The SOHO and TRACE missions reveal intricate structures above the bright active regions strewn across the 

Sun’s surface, which would otherwise appear as groups of dark sunspots in ordinary visible light. Colorized 

extreme-ultraviolet images have been melded to show that the magnetic field in the Sun’s upper atmosphere confines 

gas at widely differing temperatures virtually side by side. The Solar Dynamics Observatory, to be launched in 2008, will 

image the entire Sun every few seconds in several temperatures and measure surface velocity and magnetic field. SDO 

data will dramatically advance our ability to determine the origins of these structures and understand how they change.

How and Why Does the Sun Vary?

 How Do Planetary Systems Respond?

 What Are the Impacts on Humanity?
1

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

“Thought Generates Action” - 

 - C. Hobbs, Time Power (1987)

It is a pleasure to accept the 2005 Heliophysics Roadmap from our nation’s science 

community. It describes a renewed strategic outlook to provide essential space environment knowledge for the benefit of society and for space exploration. It communicates our 

progress made to date, our plans for the future, and our opportunities for supporting the 

Agency’s vision and mission.

The field of Space Physics has made rapid and spectacular advances over the past few 

years. Utilization of combinations of missions, each one with its own complement of instruments, has been vital to the emergence of a new view of the Sun and Solar System as 

a connected system. There will be further dramatic advances as observational techniques, 

new missions, and a new understanding of how microphysical processes influence broadscale dynamics emerge in the not-too-distant future. Each discovery impels us to ask new 

questions or regard old ones in new ways. How and why does the Sun vary? How do 

planetary systems respond? What are the impacts on humanity?

This roadmap outlines a common groundwork of inquiry spanning all the space physics 

branches of learning. It is anticipated that this will lead to a unification of long-separated 

fields of inquiry; thereby enabling the emergence of new and significant scientific insights. 

I believe that we are on the cusp of a flowing together of knowledge that will merge these 

various disciplines of research, and that the results of this process will have not only cultural and intellectual value but will also be vital to the optimization of economic and political activities in the 21st Century.

 This is our community’s most ambitious roadmap plan to date. The program includes 

forefront research and technology development as well as the development of the most 

complex flight missions conceived. The program is a balanced portfolio of small missions 

and larger spacecraft with the goal of obtaining the best science at the lowest cost that 

meet NASA’s standards for mission success. I am confident that the passage of time will 

validate the wisdom and choices of this roadmap committee and their consultants. It has 

been a privilege to associate with the people who have contributed their time and energy 

to the construction of this document.

To those involved, I extend my warmest gratitude and my admiration for a comprehensive and articulate statement. I invite you, the reader, to join this fascinating future journey 

of discovery.

 Richard R. Fisher

 Director, Earth-Sun Systems Division
2

HELIOPHYSICS

Heliophysics concentrates on the Sun and its effects on Earth, the other planets of the 

solar system, and the changing conditions in space.

Heliophysics studies the magnetosphere, ionosphere, thermosphere, mesosphere, and 

upper atmosphere of the Earth and other planets.

Heliophysics combines the science of the Sun, corona, heliosphere and geospace.

Heliophysics encompasses cosmic rays and particle acceleration, space weather and 

radiation, dust and magnetic reconnection, solar activity and stellar cycles, aeronomy 

and space plasmas, magnetic fi elds and global change, and the interactions of the solar 

system with our galaxy.

Heliophysics is the

... the comprehensive new term for the science of the Sun-

 Solar System Connection.

... exploration, discovery, and understanding of our space 

 environment.

... system science that unites all of the linked 

 phenomena in the region of the cosmos 

 influenced by a star like our Sun.

Heliophysics

helio-, pref.,

 of the Sun and environs; from the Greek helios, .

physics, n.,

 the science of matter and energy and their interactions.
3

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

Heliophysics: The New Science of the 

Sun-Solar System Connection

Recommended Roadmap for Science and Technology 

2005-2035
4

HELIOPHYSICS

Exploration and Fundamental Science

“ Something hidden. Go and fi nd it. Go and look behind the Ranges---”

 - Rudyard Kipling (1865-1936), “The Explorers” (1903)

The primary goal of the Vision for Space Exploration is the implementation of “a sustained and affordable 

human and robotic program to explore the solar system and beyond.” This simple statement has profound 

consequences on how to prioritize the science programs that are needed to accomplish the new vision. How 

is the Heliophysics community to respond, when its traditional culture has been to emphasize the scientifi c 

investigation of processes fundamental to space physics? Advice came recently from the Space Studies 

Board of the National Academy of Sciences who offered fi ve guiding principles, the fi rst of which was:

Exploration is a key step in the search for fundamental and systematic understanding of the universe 

around us. Exploration done properly is a form of science. 

The answer for the Heliophysics community becomes clear when we realize that the converse of the 

guiding principle also holds: Exploration cannot be done properly without science. 

Exploration must be well planned; history is rife with narratives of expeditions that ended fruitlessly or, 

even worse, tragically. In reality, properly implies safely, effi ciently, and economically. There are many examples of pragmatic problems facing the successful implementation of the Exploration Vision, ranging from 

the prediction of the space radiation environment to the design of the critical entry of a Crew Exploration 

Vehicle into the Martian atmosphere. In both cases, the science that enables exploration activities is drawn 

from the same science that is used to investigate the fundamental processes on the Sun, the planets, and 

in the heliosphere, from its inner boundary to the outer boundary with the interstellar medium. 

The pursuit of fundamental science not only enables Exploration but it also transforms our understanding 

of how the universe works. Current Heliophysics missions are producing a steady stream of transformational science that is rewriting the textbooks of past decades. Some recent examples:

• Direct evidence from IMAGE and Cluster that magnetic reconnection in the Earth’s protective magnetosphere can open “holes” that allow solar wind to leak through continuously for hours – much longer than 

theorists predicted. 

• Surprising information from SOHO about the hidden workings of the subsurface solar dynamo that generates the Sun’s magnetic fi eld.

• A new understanding of the acceleration sites of solar energetic particles based on RHESSI gamma ray 

observations.

• The puzzling complexities of the outer boundary of the solar wind discovered by the Voyager-1 spacecraft, our most distant explorer.

The new pragmatic challenges of the Vision for Space Exploration will dictate re-focused and intensifi ed 

scientifi c exploration. This exploration will bring forth exciting discoveries, but only if it has the same broad 

scientifi c base that has nurtured the Heliophysics community to its current maturity. Why? Because space 

science is replete with pivotal discoveries that came from unexpected quarters, from areas of sound but 

seemingly tangential research. We would not now be understanding the details of the acceleration of solar 

energetic particles revealed by RHESSI if space scientists in the 1970’s had not worked out the details of 

gamma-ray line emission in the solar atmosphere (a subject that struck many as esoteric in those days).

This Heliophysics Roadmap differs from its predecessors in that it clearly responds to the new priorities 

in space science. Nonetheless, it preserves the momentum of our community’s achievements and maintains continuity with past strategic planning. Appropriate missions recommended by previous studies are 

carried forward, while new missions are put forward that will produce the science required for the success 

of the Vision for the Moon (2020) and Mars (2035). Each of these new missions is soundly conceived in 

fundamental science objectives while being effi ciently designed to do the science that will support the Vision of Space Exploration. Well-planned science cannot help but generate exciting discoveries while still 

delivering the promised results.
5

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

Table of Contents

Preface...........................................................................................................................................1

Exploration and Fundamental Science.........................................................................................4

Forward: The Heliophysics Roadmap to Discovery and Exploration............................................6

Heliophysics Science Objectives...................................................................................................7

Executive Summary........................................................................................................................9

The Heliophysics Great Observatory in Action: The 2003 Halloween Solar Storms.....................14

Chapter 1. A New Science for the Age of Exploration: Heliophysics........................................15

The Calm Between the Storms....................................................................................................22

Chapter 2. Heliophysics: The Science........................................................................................23 Heliophysics Science and Exploration Research Focus Areas.............................................24

 Objective F - Open the Frontier to Space Environment Prediction.................................29

 Objective H - Understand the Nature of Our Home in Space..........................................37

Objective J - Safeguard the Journey of Exploration........................................................45

Chapter 3. Heliophysics: The Program.......................................................................................53

 Prioritized Implementation Strategy.................................................................................57 Anticipated Science & Exploration Achievements.............................................................58

 Solar Terrestrial Probes....................................................................................................61

Measurements of the Solar Wind Up-Stream from Earth................................................62 Living With a Star..............................................................................................................63

 The Explorer Program......................................................................................................66

 Flagship and Partnership Missions..................................................................................67

 Low Cost Access to Space..............................................................................................69

 Scientific Research and Analysis.....................................................................................70

 Research Infrastructure....................................................................................................72

Chapter 4. Heliophysics: The Missions......................................................................................75

The Evolving Heliophysics Great Observatory...............................................................76

Candidate Heliophysics Missions Linked to Research Focus Areas..........................78-79 Heliophysics Missions Currently in Development............................................................80 Near-Term Heliophysics Missions....................................................................................83 Intermediate Term Heliophysics Missions........................................................................87

 Future Heliophysics Missions...........................................................................................93

 Partnership Missions........................................................................................................95

Chapter 5. Heliophysics: Technology Investments.....................................................................99

Enabling & Enhancing Technologies.................................................................................101

Chapter 6: Heliophysics: Sun-Solar System Connection Impacts............................................107

 Education and Public Outreach.......................................................................................109

Challenges & Recommendations for Effective E/PO...................................................113

 Links Between Heliophysics and Other NASA Activities..........................................120

 Advancing U.S. Scientific, Education, Security, and Economic Interests......................124

 External Drivers of the Heliophysics Program.................................................................126

Appendices

 A. 2005 Sun-Solar System Connection Roadmap Team..............................................130 B. Bibliography of Key Agency and NRC Documents...................................................132

 C. Reconciling the Roadmap and Decadal Survey Approaches and Results................134

D. Heliophysics Mission Studies....................................................................................137

 E. Acronyms...................................................................................................................173
6

HELIOPHYSICS

The Heliophysics Roadmap to Discovery and Exploration of the Sun-Solar 

System Connection

This is a Roadmap to understanding the environment of our Earth, from its life-sustaining Sun 

out past the frontiers of the solar system. A collection of spacecraft now patrols this space, revealing not a placid star and isolated planets, but an immense, dynamic, interconnected system 

within which our home planet is embedded and through which space explorers must journey. 

These spacecraft already form a great observatory with which the Heliophysics program can 

study the Sun, the heliosphere, the Earth, and other planetary environments as elements of a 

system - one that contains dynamic space weather and evolves in response to solar, planetary, 

and interstellar variability. NASA continually evolves the Heliophysics Great Observatory by adding new missions and instruments in order to answer the challenging questions confronting us 

now and in the future as humans explore the solar system.

The three scientifi c and exploration objectives listed on the facing page require sustained research programs that depend on combining new data, theory, analysis, simulation, and modeling. Our program pursues a deeper understanding of the fundamental physical processes that 

underlie the exotic phenomena of space, such as magnetic reconnection, while at the same time 

targeting specifi c hazards, such as solar energetic particles. The result will represent not just a 

grand intellectual accomplishment; it will also provide the predictive capabilities essential to future human and robotic exploration of space and will serve important societal needs.

Over the next ten years NASA will launch spacecraft to investigate the dynamo deep within the 

Sun, image its roiling surface, and perhaps even probe the intricate structures of its torrid atmosphere. Constellations of spacecraft, separating variations in time and space, will measure the 

complex responses of the upper atmospheres of the Earth and Mars, Jupiter, and even the Sun. 

Observations of unique regions near Earth will allow us to understand the key physical processes 

regulating our local environment. 

Later activities will push the limits of our technological capabilities. The power of the Heliophysics Great Observatory will expand so that new-found understanding can be used to predict 

hazardous events wherever explorers may travel. A high-speed probe will directly measure the 

current interstellar environment from which the heliosphere shields us. Resolved images of other 

stars will provide amazing insights into the varying activity of our own Sun. External infl uences 

affecting the habitability of planets, including our own, will be understood.

How can this all be accomplished?

The Heliophysics endeavor relies on fi ve major mission programs. The Solar Terrestrial Probes 

focus primarily on fundamental science questions. Living With a Star missions and partnerships 

target knowledge of processes that directly affect life and society. The fl exible Explorer program 

provides an effi cient means of achieving urgent strategic goals that is highly responsive to new 

knowledge, technology and priorities. Challenging Flagship and Partnership missions address 

important goals that cannot be funded in the baseline program. The Heliophysics Great Observatory coordinates new and existing mission elements to confront broader problems.

Implementation of this ambitious program requires a comprehensive approach. The missions 

described in the Roadmap will be effective only with strengthened programs of supporting research and technology to develop the models, theories, and new instrumentation necessary to 

continuously redirect and reform future science and exploration activities. Virtual observatories 

and advanced information systems must be developed to provide data access and computing 

resources. The program cannot be long sustained unless the public appreciates the important 

benefi ts of NASA’s Heliophysics program and new scientists and engineers enter the fi eld, for 

example through the Low Cost Access to Space program. 

The Heliophysics Roadmap Committee derived these objectives with a set of targeted achievements to support the highest level of objectives of the U.S.A. for NASA’s program. Prioritizing 

investigations from the rich set of options was a diffi cult task.

 Join us on this exciting path of exploration, discovery, and service to humanity.
7

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

Heliophysics Science Objectives:

Open the Frontier to Space 

Environment Prediction

Understand the fundamental 

physical processes of the space 

environment - from the Sun to 

Earth, to other planets, and beyond to the interstellar medium

Understand the Nature of 

Our Home in Space

Understand how human society, technological systems, 

and the habitability of planets 

are affected by solar variability 

interacting with planetary magnetic fi elds and atmospheres.

Safeguard the Journey 

of Exploration

Maximize the safety and 

productivity of human and 

robotic explorers by developing the capability to 

predict the extreme and 

dynamic conditions in space
8

HELIOPHYSICS
9

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

Executive Summary

We live in an exciting environment: the heliosphere, the exotic outer atmosphere of a 

star. The space beyond Earth’s protective 

atmospheric cocoon is highly variable and 

far from benign. It is the one part of the cosmos accessible to direct scientifi c investigation, our only hands-on astrophysical laboratory. Our technological society is increasingly 

susceptible to space weather disturbances in 

this curious region. A host of interconnected 

physical processes, strongly infl uenced by 

solar variability, affect the health and safety 

of travelers in space and the habitability of 

alien environments. We call the science of the 

Sun-Solar System Connections ‘heliophysics.’

 Building on NASA’s rich history of exploration 

of the Earth’s neighborhood and distant planetary systems, we are poised to develop the 

quantitative knowledge needed to help assure 

the safety of the new generation of human and 

robotic explorers. The Heliophysics Program 

has been completely reevaluated to address 

the needs of the Vision for Space Exploration.

NASA’s future research and exploration 

within its Heliophysics program aims to “explore the Sun-Earth system to understand the 

Sun and its effects on Earth, the solar system, 

and the space environmental conditions that 

will be experienced by explorers, and to demonstrate technologies that can improve future operational systems.” We have unfolded 

this articulated strategic goal into the three 

broad science and exploration objectives.

• Open the Frontier to Space Weather 

Prediction: Understand the fundamental 

physical processes of the space environment – from the Sun to Earth, to other planets, and beyond to the interstellar medium. 

• Understand the Nature of Our Home in 

Space: Understand how human society, technological systems, and the habitability of planets are affected by solar variability interacting 

with planetary magnetic fi elds and atmospheres.

• Safeguard the Journey of Exploration: Maximize the safety and productivity of human and robotic explorers by 

developing the capability to predict the extreme and dynamic conditions in space.

These will be accomplished by studying 

the Sun, the heliosphere, and planetary environments as elements of a single inter-connected system, one that contains dynamic 

space weather and evolves in response to solar, planetary and interstellar conditions. Focused research programs addressing specifi c 

space environmental hazards will help guide 

the design and operations of safe and productive missions. At the same time we will pursue 

a deeper understanding of the fundamental 

physical processes that underlie the awesome 

phenomena of space. Such an understanding 

will represent not just a grand intellectual accomplishment for our times - it will also provide knowledge and predictive capabilities essential to future human and robotic exploration 

of space and will serve key societal objectives 

in important ways. Herein, we describe current plans for NASA’s research programs in this 

area and the guiding principles we will follow in 

pursuit of forthcoming exploration challenges.

This scientifi c exploration will target the 

highly coupled system that stretches from the 

Sun’s interior to planetary neighborhoods and 

the vast expanses of interplanetary space. We 

are already transforming human understanding 

of this fascinating global system of systems, 

so closely connected that a single explosive 

event on the Sun can produce power outages on the Earth, degradation of solar panels 

on interplanetary spacecraft, fatal damage to 

instrumentation in Mars orbit, and auroral displays at Saturn – effects that span the entire 

Heliophysics Mission Roadmap - Recommended and Currently Funded. The fi gure on page 8 illustrates 

the prioritized mission schedule through 2035. The top panel shows the recommendations for the Solar 

Terrestrial Probes and Living With a Star programs. Slots for competitively selected Explorers that contribute to our strategic objectives along with the partnership and fl agship missions that require additional 

funding appear in the center. The bottom panel shows the endorsed schedule for the STP and LWS programs assuming the current budget level. See page 55 for details.
10

HELIOPHYSICS

solar system. By expanding and deepening 

that understanding, we will not only develop 

a predictive capability to address hazards to 

space travelers and to important technological assets closer to home, but we will learn 

how the fundamental space processes interact to affect the habitability of other distant 

environments, beyond our own solar system.

In keeping with our requirements driven approach, each objective has been associated 

with research focus areas and scientifi c investigations. Targeted outcomes for each decade 

have been identifi ed for each objective and 

these have led to our prioritized recommendation for missions. Our goals will be achieved by 

pursuing three groups of strategic missions and 

the rapid-response Explorer Program, all supported by programs for research and analysis, 

technology development, and education and 

public outreach. Investigations supported by 

missions that can launch in the next ten years 

are described below. Subsequent mission candidates for each line are described in the report.

The Solar-Terrestrial Probe (STP) missions 

address fundamental science questions about 

the physics of space plasmas and the fl ow of 

mass and energy through the solar system. 

Three STP missions already begun can be 

launched in the next decade. Solar–B, a partnership mission led by Japan, will be launched 

in 2006 to observe how magnetic fi elds on the 

Sun’s surface interact with the Sun’s outer atAnticipated Heliophysics Science and Exploration Achievements

Each anticipated achievement in the table has been developed from the Heliophysics research focus areas. 

Each targeted outcome requires advances in understanding of physical processes. Measurement capabilities must be available to develop that knowledge. Deployment of missions, development of theoretical understanding, and availability of infrastructure systems are required to provide that measurement capability. 
11

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

This fi gure illustrates the fl ow of requirements from an overarching strategic goal to principal science objectives, through implementation, to anticipated achievements, and impacts relative to the goal and objectives. 

mosphere, which extends millions of miles 

into space. The STEREO mission, also to be 

launched in 2006, will provide an unprecedented three-dimensional view of the magnetic fi eld 

and particle fl ows throughout the inner heliosphere. Third, the Magnetospheric Multiscale 

(MMS) mission, to be launched in 2011, will 

explore the fundamental physical processes 

responsible for the transfer of energy from the 

solar wind to Earth’s magnetosphere and the 

explosive release of energy during solar fl ares.

The Living With a Star (LWS) missions will 

enhance knowledge of the Earth–Sun system that directly affects life and society. The 

budget enables the launch of four synergistic 

missions by 2015. The Solar Dynamics Observatory (SDO), to be launched in 2008, will 

observe the Sun’s interior, surface, and atmosphere continuously to determine the physical 

causes of solar variability. The Radiation Belt 

Storm Probes (RBSP), to be launched in 2011, 

will determine how space plasmas are accelerated to hazardous energies, thereby enabling 

scientists to predict changes to planetary radiation environments and protect space explorers. The Ionospheric Thermospheric Storm 

Probes and Imager (ITSP), to be launched in 

2015, will help scientists understand, to the 

point of acquiring a predictive capability, the effects of geomagnetic storms on the ionosphere 

/ thermosphere – the region of the atmosphere 

approximately 50 to 800 miles above Earth’s 

surface. Last, the Inner Heliospheric Sentinels 

IH Sentinels), also to be launched in 2015, will 

provide understanding of the propagation and 

evolution of eruptions and fl ares from the Sun 

to the planetary environments. Partnership is 

crucial to LWS and we recommend collaboration on ESA’s Solar Orbiter mission in this time 

frame. The LWS Space Environment Testbeds 

provide a valuable opportunity for technological partnerships with spacecraft designers. 

Flagship and Partnership Missions address highly challenging and important goals, 

but are not part of the baseline funded program. Flagship missions cannot be afforded 
12

HELIOPHYSICS

New knowledge of this system enables 

safe and productive exploration. Exploration 

enables new scientifi c understanding. The 

knowledge has utility for society. Our high priority science and exploration objectives address each of these needs. The program is 

vital, compelling and urgent.

without additional resources. The Solar Probe 

mission will explore the inner frontier of our solar system; the mission is ready to fl y and is 

our highest priority for new resources. Much 

later fl agships are an interstellar probe and a 

stellar imager. Partnerships must leverage opportunities available in other programs. The 

Pluto/Kuiper mission already includes space 

plasma instrumentation to examine solar wind 

interactions out to the most remote bodies in 

our solar system. The Solar Sail Demo mission will enable future missions of much higher delta-V capability. A Jupiter Polar Orbiter 

(Juno) mission will enable us to compare the 

solar wind interaction with a rapidly rotating 

magnetosphere to that of Earth. The Aeronomy and Dynamics at Mars (ADAM) mission, 

a potential Mars Scout, will provide information about the Martian atmosphere in support 

of human and robotic exploration of Mars. 

The Explorer Program provides a vital and 

effective means of achieving urgent strategic 

goals in a timely way. Explorers are highly responsive to new knowledge, new technology, 

and updated scientifi c priorities by supporting smaller missions that are conceived and 

executed in a relatively short development 

cycle, based on open solicitation of concepts 

from the entire community. The program also 

enables participation in missions-of-opportunity provided by other national or international 

agencies. Three Explorers currently in development are relevant to this Roadmap. AIM will 

determine why polar mesospheric clouds form 

and why they vary and will determine the mesospheric response to solar energy deposition 

and coupling among atmospheric regions. The 

fi ve-spacecraft THEMIS mission will elucidate 

the mechanisms of transport and explosive release of solar wind energy within the magnetosphere and is a technology precursor to future 

‘constellation’ missions. The recently selected 

IBEX mission will image the edge of our solar system to examine galactic cosmic rays 

and particle acceleration at the heliopause.

The connected system we study cannot be 

adequately measured by single missions. The 

currently operating spacecraft missions supporting Sun-Solar System connections research 

collectively constitute a Great Observatory that 

can address the fundamental challenge for heliophysics science. The Heliophysics Great 

Observatory (page 66) provides the simultaneous measurements in multiple locations 

needed to resolve temporal and spatial changes and to understand the interactions of complex systems of regimes. As we progress in the 

exploration of space, this essential capability 

must evolve to support ever more comprehensive understanding and predictive capabilities. 

In the years ahead, portions of this spacecraft 

fl eet will be confi gured into “smart” constellations - sets of strategically-located satellites 

that provide data to virtual observatories. Researchers will work together to provide the 

timely, on-demand data and analysis to users 

who enable the practical benefi ts for scientific research, national policymaking, economic 

growth, hazard mitigation, and the exploration 

of other planets in this solar system and beyond.

Several smaller but no less crucial program 

elements support the implementation of the 

Heliophysics program. The Low Cost Access to Space (LCAS) program uses ever 

Sun, Earth, Moon, Mars, and Beyond...
13

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

more capable rockets and balloons to provide 

unique science, community development, and 

technology and instrument development. The 

interplay among observation, simulation, 

modeling, and theory is essential for the vitality of our space science program. A model 

or simulation often provides specifi c predictions to spur the course of future observation. 

Unexplained observations have led to the development of new theories and the creation of 

entirely new models. Heliophysics must continue supporting fundamental theory, modeling, 

data assimilation, and simulation programs, 

the development of space weather modeling 

frameworks, and the transition to applicationsbased codes necessary for space weather operational predictions. The burgeoning maturity 

of current, comprehensive theoretical modeling systems, spanning many regions and times 

scales, provides the essential underpinnings 

for NASA’s effort to integrate and synthesize 

knowledge of the complete system of systems.

As an essential element of its plan to 

meet these challenging requirements, 

NASA will invite active participation by international and national partners to support the exploration and research program

Education and public outreach have become a natural part of Heliophysics activities. 

Building on this foundation, we recommend 

that E/PO activities stemming from the science achievements or milestones be developed to support the following fi ve messages:

• NASA keeps me informed about what’s going on with the Sun

• The Solar System is an astrophysical laboratory for NASA

• NASA science helps us protect our society 

from hazardous space weather

• NASA science helps us understand climate 

change

• NASA science helps keep space explorers 

safe and supports exploration activities

Heliophysics embraces the development, 

infusion, and study of new technology, both 

for its stimulating effect on science and because of the key role that understanding and 

predicting the space environment presents for 

the safety of other NASA missions and of our 

global infrastructure that is increasingly spacebased. Continuing progress requires technological development in a number of key areas.

• Developing compact, low-cost spacecraft 

and launch systems;

• Achieving high ∆V propulsion (solar sails);

• Designing, building, testing, and validating 

the next generation of Heliophysics instrumentation;

• Returning and assimilating large data sets 

from across the solar system;

• Analysis, data synthesis, modeling, and visualization of plasma and neutral space environments throughout the solar system.

• Enabling space weather prediction. 

This proposed Heliophysics program has 

been derived directly from NASA’s new priorities. Still, it should not be surprising that 

the new plan is largely consistent with previous recommendations. The long-term goals 

and the near-term budget have shifted since 

the solar and space physics strategy was presented in the National Research Council’s 2002 

decadal report, The Sun to the Earth – and Beyond. However, as noted in the 2004 NRC update, Solar and Space Physics and Its Role in 

Space Exploration, “the basic priorities of the 

decadal strategy are still valid for the simple 

reason that the fundamental principles used 

in constructing the strategy were the need for 

a balanced program of basic and applied research that endeavors to recognize the solarplanetary environment for the complex system 

that it is. We do not know enough today to 

perform the predictive task required of us by 

the exploration initiative, and only by pursuing 

fundamental knowledge and employing a system-level approach can we hope to succeed.”

 Our present generation of space researchers has inherited a fantastic legacy from the 

exploratory missions and discoveries of earlier decades. Our success in conducting a 

robust program of exploration at new scientifi c frontiers will leave to future generations 

a similar gift of achievement and inspiration. 

Because the purpose of exploration is to understand the unknown, the precise benefi ts 

of their future space research and their path 

to success defy prediction. We do know 

that progress will require constant adaptation to exciting diversions and new directions.
14

HELIOPHYSICS

Such events, in addition to being 

disruptive to society, are important 

from a research point of view. Because they offer clearer signatures 

of the solar source mechanisms 

and propagation characteristics, the 

ensuing planetary effects and consequences can be unambiguously 

determined. The plasma, particle 

and electromagnetic consequences 

of such events are the focus of this 

roadmap. The goal of which is to understand the Sun, heliosphere and 

planetary environments as a single 

connected system and to apply this 

knowledge for the benefi t of society and the exploration of the solar 

system. We will reach this goal by 

strategically evolving the distributed 

network of spacecraft we call the Heliophysics Great Observatory.

Today’s Heliophysics Great Observatory

The Heliophysics Great Observatory in Action

The 2003 Halloween Storms

In late October and early November 2003 a large cluster of active regions on the Sun produced 

a extended series of Coronal Mass Ejections (CMEs) that caused the most spectacular set of 

events ever observed to fl ow through the solar system. The solar storms, referred to as the 2003 

Halloween Storms, drove a blast wave that pushed the solar system boundary about 1.5 billion 

miles deeper into interstellar space and expanded the volume of the Sun’s corner of the galaxy 

by almost a third.

Only recently have enough research spacecraft been in place to track such blast waves as they 

propagate through the solar system revealing that solar storms are both universal and ubiquitous 

in their infl uence. This fl eet of spacecraft, NASA’s Great Observatory for the Sun-Solar System 

connection, observed the Halloween Storms as they blasted by Earth within a day and past Mars 

just a few hours later, they detected radio bursts from colliding CMEs as the storms streamed 

past Jupiter and Saturn. The most distant observations were taken at the outer edge of the solar 

system by the Voyager spacecraft almost eight months later.

At Earth within a few days the storms produced half as much of the deadly 30-50 MeV particle 

radiation as the total emitted from the Sun in the previous 10 years and created a new radiation 

belt at Earth that lasted for several weeks. Southern Sweden experienced a blackout, surge currents were observed in Swedish pipelines, GPS signals were degraded or occluded, and several 

Mount Everest teams reported interference in high-frequency radio communications. The storms 

caused aircraft to be rerouted and spacecraft operators reported electronic upsets, data noise, 

signifi cant proton degradation to solar arrays, orbit degradation, high levels of accumulated radiation, and proton heating. Fortunately, no NASA satellites near Earth were severely damaged, a 

tribute to advance planning and engineering, although the Mars Radiation Environment Experiment (MARIE) instrument on the Mars Odyssey spacecraft was disabled by radiation at Mar’s 

orbit.

The Sun regularly sends massive explosions of radiative plasma hurtling through the solar 

system, some with as much energy as a billion megaton bomb. Scientists have identifi ed just 

13 other events as extreme as the Halloween storms, including the historic Carrington event of 

September 1, 1859.
Chapter 1.

A New Science for the Age of Exploration:

Heliophysics
16

HELIOPHYSICS

As We Leave the Protective Cocoon of the Earth System, Our Explorers Will 

Move from a Gravitationally Dominated to a Magnetically Driven Environment

Galaxies Heliosphere Stellar Magnetism

Gravitationally Driven

Familiar Physics - Two Forces:

• Gravity

• Pressure

Magnetically Driven

Heliophysics - Three Forces:

• Gravity

• Pressure

•Magnetism

Space Weather

Stars/Sun:

CMEs Flares

Solar 

Variability

Total Solar 

Irradiance & 

Climate Magnetars Shocks

Atmospheric 

Chemistry

Aurorae Ionospheres Planetary Magnetospheres 

& Atmospheres

Planets:

The dynamic interplay between the three forces (pressure, gravity, and electromagnetism) 

in the various venues of the solar system - the Sun’s atmosphere; the relationship between 

the Sun and the heliosphere; the interfaces between planets, their magnetospheres and 

the heliosphere; and the boundary between the solar system and the galaxy

Planets
17

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

Chapter 1

A New Science for the Age of 

Exploration: Heliophysics

Space exploration has transformed our understanding of the solar system. It has revealed 

a fascinating nested system of systems, so 

closely connected that an explosive event on 

the Sun produces measurable effects that span 

the entire solar system. Through judicious use 

of a number of operating missions, we have 

achieved system surveillance over parts of the 

heliosphere and have been able to examine 

causal linkages between its elements. In late 

2003 we observed an event that caused spectacular coronal mass ejections, power outages 

on the Earth, degradation of spacecraft solar 

panels and circuits, destruction of atmospheric 

ozone, infl ation and ablation of planetary upper 

atmospheres, fatal damage to instrumentation 

in Mars orbit, auroral displays on Saturn, and, 

months later, radio disturbances at the edge of 

the solar system where it meets the interstellar medium. In short, we have observed that 

space contains weather and that it can affect 

us (pg 6 & 14).

Recognizing that comprehensive study of 

this cohesive system has no name, the division 

has coined the term “Heliophysics” to unite the 

disciplines that study the linked phenomena in 

the region of space infl uenced by the Sun, our 

star. This chapter highlight some of the key 

contributions of heliophysics.

Classically, the structure and processes of 

our environment had been understood in terms 

of gravitation and pressure. Since space exploration began in 1957, we have learned that 

space is fi lled with matter and electromagnetic 

fi elds whose importance is belied by their invisibility. Unsheltered from the Sun’s pervasive 

ultraviolet radiation, matter in space enters the 

fourth state: a conducting plasma of electrically 

charged electrons and ions, fl owing and reacting to highly variable electromagnetic forces. 

Common human experience provides little experience or intuition about the behavior of such 

plasma atmospheres.

Owing to its conductivity, moving plasmas 

generate electrical currents and magnetic 

fi elds. Many exotic phenomena ensue, some 

of which resemble turbulent fl uid fl ows, but impart signifi cant energy to a subset of particles; 

so much that they can be dangerous to semiconductor circuits or living tissue. Magnetic 

fi eld lines act to organize their source plasmas 

into coherent cells, much as droplets of water 

are defi ned by surface tension. When such 

cells come into contact, their magnetic fi elds 

may reconnect, creating a coupling between 

them so that motions of one drive motions of 

the other. Electrical currents fl ow to generate 

Our program will help assure the safety and 

productivity of the next generation of human 

and robotic explorers.

At the same time we will pursue a deeper 

understanding of the fundamental physical 

processes that underlie the awesome 

phenomena of space.

We will develop a predictive capability to 

address hazards to important technological 

assets closer to home and discover how 

fundamental space processes may affect 

the habitability of other distant environments 

beyond our own solar system.
18

HELIOPHYSICS

the coupling forces, charged particles are accelerated, sometimes explosively as in solar 

fl ares.

Such electromagnetically driven processes 

act at the center of every stellar system. Our 

own solar system is controlled by the Sun, a 

magnetically variable star. Because our solar 

system is the one part of the cosmos accessible to direct scientifi c investigation, it provides 

our only hands-on astrophysical laboratory for 

understanding these universal processes.

Heliophysics is the new science for the age 

of exploration. Implementing the Vision for 

Space Exploration will eventually free humankind from the gravitational forces that have held 

us through history. Space explorers will learn 

to live within the magnetically controlled space 

environment and, through our NASA exploration missions, every citizen will be able to see 

and experience these things.

The Earth and Sun are linked together to form 

the system that has given origin and sustenance to our lives. The story of how this came 

to be over the history of the solar system is 

one of the most compelling mysteries faced by 

humankind. The physical processes and the 

evolutionary paths embedded in this combined 

system are studied in the Earth-Sun System DiSeveral kinds of space plasma simulation models have been developed to provide a theoretical understanding of the fl ow of energy from the Sun through interplanetary space to the Earth’s magnetosphere. 

This fi rst frame illustrates the progression of a coronal mass ejection (CME). Shown are magnetic fi eld lines 

(white) and magnetic fi eld strength (low = blue to high = red) 20 hours into an event. The sun is the small 

black dot at the center of the red glow to the left. The CME is at the right riding on top of the expanding fl ow 

of the solar wind at speeds up to 2,000 kilometers per second.

vision of NASA’s Science Mission Directorate. 

We examine the Earth and Sun system today 

for insights into questions concerning how the 

system evolved so as to produce and sustain 

life, what will happen to this unique environment through the course of time, and how it 

will affect us.

With human space activity confi ned to low 

Earth orbit since the mid-1970’s, we have been 

reconnoitering the solar system (and beyond) 

using robotic spacecraft and telescopes. In 

2005, Voyager passed through the solar wind 

termination shock and into the heliosheath, 

nearing the outer edge of the solar system. 

Though we have not yet probed the inner 

boundary of the solar atmosphere directly, 

the Sun is bright enough to reveal a great deal 

about itself through remote imaging, spectroscopy, and polarimetry. 

With the fi rst general survey of the solar system nearly complete, explorers are now beginning to revisit the planets, including Earth, for 

studies of greater depth. The region around the 

Earth remains an important astrophysical laboratory for the study of the physical processes 

that are of broad relevance to astrophysics. 

Moreover, these processes are by now known 

to have infl uenced the habitability of the Earth 
19

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

This frame is a continuation of the same simulation as the 

CME impacts the Earth’s magnetosphere creating a geomagnetic storm, which fi rst manifests itself as large, episodic variations in the Earth’s magnetic fi eld. The electromagnetic pulses can produce a new radiation belt in minutes, 

not days, as normally occurs.

False color composite picture of the Sun illustrating the 

source of the disturbance shown in the simulation. The 

Sun observed in extreme UV is the center object colored 

in green. The areas in red and blue are views of the Sun’s 

atmosphere (corona) where the CME can be seen as white 

areas moving rapidly away from the Sun.

in time and so are relevant to the possible existence of life elsewhere in the solar system or 

the universe. Investigators have barely begun 

to scratch the surface of the history of our solar system over geologic time and have only 

recently determined that planets are commonplace around other stars. In at least one such 

case observers can discern the signature of an 

atmosphere being ablated by a stellar wind. In 

another case, X rays are emitted from a young 

star that is not fully ignited, showing that electromagnetic and plasma processes become 

active very early in the life of a planetary system. 

The United States is now embarking on an 

ambitious new journey of exploration to the 

Moon, Mars, and beyond. NASA has been 

challenged to establish a sustained presence 

on the Moon by the end of the next decade 

with the purpose of enabling Martian exploration thereafter. The will to achieve this Vision 

for Space Exploration presents the agency with 

great opportunity and sobering demands. 

Success in this venture requires advanced 

understanding of the complex physical systems that link the variable star at the center 

of our solar system with the Earth and other 

planets. The harsh and dynamic conditions in 

space must be characterized and understood 

in some detail if robots and humans are to 

safely and productively travel to and explore 

the Moon and Mars. 

The biological effects of the energetic particle radiation environment outside of low-Earth 

orbit remain largely unknown. Astronauts 

aboard the International Space Station (ISS) 

accumulate signifi cant radiation exposure and 

energetic particle events impact space station operations. Travel outside Earth’s protective magnetic cocoon, whether to the Moon 

or Mars, will require new predictive capability 

for solar particle events. Even well designed 

hardware is damaged or degraded by extreme 

conditions in space. And astronauts spending 

more than a few days in space will need a way 

to take shelter from episodic exposure to debilitating doses of solar energetic particles.

Equally important is the need to investigate 

the space weather and solar variability that affect critical technologies used on Earth. For 

example, satellite communications, navigation, remote sensing, and power distribution 

are subject to problems because of variations 

in the Earth’s ionosphere that are not currently 

understood. Increasing reliance on vulnerable 

global systems demands active management 

in response to variations in the space environment. In many ways, our space weather 

approach resembles earlier steps taken by 

scientists to understand and predict weather 

in the Earth’s atmosphere. We too must ob-
20

HELIOPHYSICS

serve and understand the detailed phenomena, generate theoretical models that can be 

validated and verifi ed against observed reality, build data-assimilative predictive systems, 

and then develop operational decision support 

systems closely tailored to the needs of endusers and rigorously tested and improved over 

time. In this way and by these means, NASA’s 

Heliophysics program will bring sound science 

to serve society.

Space weather is in some ways analogous to 

the tropospheric weather that is so familiar to 

us, yet remains diffi cult to predict beyond a few 

days. In other ways it is fundamentally different. It is analogous in its nonlinear complexity, 

though across an even greater range of physical and temporal scales. Systems this large 

simply cannot be reduced to a linear combination of interacting parts, no matter how detailed the study of those parts. Space weather 

is fundamentally different in that electricity and 

magnetism are at least as important as the 

more familiar forces of gravity and pressure. 

Measuring, characterizing, and understanding these processes cannot be accomplished 

with images and common intuition. Localized 

measurements cannot merely be interpreted 

to generate a global picture. Conversely, the 

global picture does not provide insight into the 

small-scale physical processes of the system. 

For example, the magnetic reconnection that 

regulates much of the interaction between the 

solar wind and the Earth’s magnetosphere cannot be observed remotely and it takes place 

in a rapidly moving location several Earth radii 

above the planet on a spatial scale of a few 

100

meters 103meters 106meters

1 to 10s of meters

1 to 10s of kilometers

thousands of kilometers

thousands of kilometers

ionospheric irregularities diffusion regions of planetary-scale waves magnetic reconnection

Interacting Powers of Ten: Our work over the past few decades have taught us enough about our local space 

environment to know that our task to produce reliable space weather predictions is a formidable challenge

In-situ sampling

Small Constellations

108

meters

solar granules and sun spots

Our approach to experimentally probing 

this vast system of systems is three-fold:

• Identify the weakest links in our 

understanding of the coupled system and 

deploy targeted missions to resolve those 

science questions.

• Utilize all NASA deployed assets as a 

distributed sensor net to sample large-scale 

phenomena.

• Combine these necessarily sparse data 

with modeling and theory to achieve systemwide understanding.

kilometers and temporal scale of several milliseconds.

Answering a specifi c science and/or exploration question often requires a narrowly focused 

mission to a particular location with a unique 

instrument. For example, measuring fl ows in 

the solar interior requires a long, continuous 

series of simultaneous velocity measurements 

at millions of locations on the solar disk. However, Sun – Solar System connection science 

increasingly depends on combining multi-point 

in situ measurements with remote sensing. 

Again, by analogy with meteorology, combining a network of distributed local observations 

with global measurements (a meteorological 

Great Observatory) enables the development 

and testing of predictive models that improve 

with time and experience.

Currently the Heliophysics Great Observatory includes satellites that (for example) hover 

Space-based remote sensing
21

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

planetary magnetospheres

1012

meters 1013meters 109meters

tens to hundreds of RE

106-7

meters

coronal mass ejections our solar system our solar system’s infl uence on our galaxy hundreds of Au tens of Au

Solar System Great Observatory

Observations of solar system-scale and planetary- scale phenomena, and of microphysical plasma processes, will be required. 

This requires a range of observational techniques: in situ, imaging, constellations, and the Heliophysics Great Observatory.

near L1 – a million miles upstream in the solar wind, circle over the Sun’s poles, orbit the 

Earth in various confi gurations, and have just 

reached the fi rst boundary between the interstellar medium and the Sun’s domain, the termination shock. 

As each set of scientifi c problems is resolved, new mysteries emerge and the Heliophysics Great Observatory evolves with the 

addition of new spacecraft. Solar-B will help 

understand the creation and destruction of solar surface magnetic fi elds, variations in solar 

luminosity, and the dynamics of the solar atmosphere. Soon the two STEREO spacecraft 

will drift away from Earth to provide the fi rst 

stereoscopic views of the Sun and inner heliosphere. The Solar Dynamics Observatory 

(SDO) will image the Sun’s interior, surface, 

and atmosphere from geosynchronous orbit. 

Observing the terrestrial response, the Radiation Belt Storm Probes (RBSP) will investigate 

the processes that accelerate particles to hazardous radiation levels, and the four Magnetospheric Multi-Scale (MMS) spacecraft will fl y in 

tight formation to explore the multiple scales 

of reconnection, turbulence, and particle acceleration in the magnetosphere of the Earth. 

Solar Probe, when funded, will transform our 

understanding of the physical processes that 

control the heating of the solar corona, the acceleration of the solar wind, and the release of 

eruptive activity.

This recommended science and exploration 

roadmap for the Heliophysics Division elaborates the strategic planning consequences 

of a stated U.S. national objective for NASA: 

“Explore the Sun-Earth system to understand 

the Sun and its effects on Earth, the solar system, and the space environmental conditions 

that will be experienced by human and robotic 

explorers, and demonstrate technologies that 

can improve future operational systems.” The 

resulting science and explorations objectives 

are explained in the next chapter. Implementation plans follow that span the next 30 years. 

The document concludes with an explanation 

of the links to other NASA activities.

New knowledge of this system enables safe 

and productive exploration. Exploration enables new scientifi c discovery and understanding. The knowledge has utility for society. Our 

high priority science and exploration objectives 

address each of these needs. The program is 

vital, compelling, and urgent.

tens to hundreds of RE

Challenges to achieving a quantitative, predictive understanding of this complex “system of systems”

• Regulation of global and interplanetary 

 structures by microphysical processes

• Multi-constituent plasmas and complex 

 photo chemistry

• Non-linear dynamic response

• Integration and synthesis of multipoint 

 observations

• Development of data assimilative 

 models and theory

• Amalgamation of interdisciplinary 

 communities and tools
22

HELIOPHYSICS

The Calm Between the Storms 

Powerful events such as the 2003 Halloween space storms (page 6) obviously affect astronauts, satellites, communication and electrical power systems. But it may seem that the space environment is usually 

benign and unimportant because such storms are rare. In fact, the constant variation of the space environment makes the time between storms anything but calm.

Magnetic active regions on the Sun emerge and decay over days to weeks. The numbers of active regions varies regularly with the 11-year solar cycle and erratically over longer time scales - up to centuries. 

The patchy distribution of regions over the Sun produces variation at the 27-day solar rotation period. 

Many phenomena – emission of visible light, intensity of short wavelength radiation, solar wind characteristics, and blocking of galactic 

cosmic rays – vary signifi cantly with the time scales of the solar magnetism, even without storms.

Light from the solar surface directly heats the Earth’s surface and 

lower atmosphere. Dark sunspots and bright faculae in magnetic regions alter the emission of light from the surface enough to affect the 

climate over long intervals.

The corona above magnetic regions is heated to millions of degrees 

and emits strong and variable amounts of X-rays, EUV, and UV radiation. The radiation heats, dissociates, and ionizes the atmospheres of 

Earth and other planets, producing our ozone layer, the ionosphere, 

and the thermosphere. It alters atmospheric chemistry and temperature, which in turn modifi es the mixing of molecules over height and 

latitude. As these layers heat and cool, they become more and less 

dense, changing the drag that slows satellites until they reenter.

The solar wind, striking Earth’s magnetic fi eld, drives the acceleration of energetic particles that fi ll the radiation belts. By contrast, 

Mars has no global magnetic fi eld, and the solar wind directly impacts 

and strips away Mars’ upper atmosphere. The wind’s magnetic fi eld, 

constantly reshaped by change on the Sun even in absence of solar 

events, can power intense geomagnetic storms, with the whole array 

of energetic particle acceleration, aurora, and disturbances of satellites systems.

Coronal holes above stable solar areas power the solar wind, which 

carries magnetic fi elds with it. The magnetized solar wind, fi lling the 

heliosphere, defl ects many of the cosmic ray particles that fi ll the rest 

of the galaxy.

Understanding the varying space environment on all timescales is 

the motive for our Heliophysics Great Observatory and for the new 

missions planned in this Roadmap. From the climate of Sun and 

Earth, to travel to other planets, and out to the space between the stars, the Heliophysics program seeks to 

predict these variations that we know – and those we have yet to discover.

Annual soft x-ray images from 

Yohkoh (above) show dramatic 

changes over an 11-year solar cycle. Less regular, but equally large, 

changes can occur on shorter (27-

day) and much longer (millennial) 

time scales. The solar wind velocity distribution (below) follows 

a similar pattern. Fast (blue) solar 

wind originates in dark x-ray coronal holes.
Chapter 2.

Heliophysics: The Science
24

HELIOPHYSICS

HELIOPHYSICS SCIENCE & EXPLORATION RESEARCH FOCUS AREAS:

 Open the Frontier to Space Environment Prediction

 Understand the fundamental physical processes of the space environment -

 from the Sun to Earth, to other planets, and beyond to the interstellar medium.

F1. Understand magnetic reconnection as revealed in solar fl ares, coronal mass ejections, and 

 geospace storms.

F2. Understand the plasma processes that accelerate and transport particles.

F3. Understand the role of plasma and neutral interactions in nonlinear coupling of regions 

throughout the solar system.

F4. Understand the creation and variability of magnetic dynamos and how they drive the 

dynamics of solar, planetary and stellar environments.

 Understand the Nature of Our Home in Space

 Understand how human society, technological systems, and the habitability 

 of planets are affected by solar variability interacting with planetary magnetic 

 fi elds and atmospheres.

H1. Understand the causes and subsequent evolution of solar activity that affects Earth’s 

 space climate and environment.

H2. Determine changes in the Earth’s magnetosphere, ionosphere, and upper atmosphere to 

enable specifi cation, prediction, and mitigation of their effects.

H3. Understand the role of the Sun as an energy source to Earth’s atmosphere and, in 

 particular, the role of solar variability in driving change.

H4. Apply our understanding of space plasma physics to the role of stellar activity and 

 magnetic shielding in planetary system evolution and habitability.

 Safeguard the Journey of Exploration

 Maximize the safety and productivity of human and robotic explorers by 

 developing the capability to predict the extreme and dynamic conditions in 

 space.

J1. Characterize the variability, extremes, and boundary conditions of the space environments 

that will be encountered by human and robotic explorers.

J2. Develop the capability to predict the origin and onset of solar activity and disturbances 

associated with potentially hazardous space weather events.

J3. Develop the capability to predict the propagation and evolution of solar disturbances to 

enable safe travel for human and robotic explorers.

J4. Understand and characterize the space weather effects on and within planetary 

environments to minimize risk in exploration activities.
25

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

This generation of space researchers has inherited a fantastic legacy from the exploratory 

missions and discoveries of earlier decades. 

Our success in conducting a robust program of 

exploration at new scientifi c frontiers will leave 

to future generations a similar gift of achievement and inspiration. Because the purpose of 

exploration is to understand the unknown, the 

precise benefi ts of their future space research 

and their path to success defy prediction. We 

do know that progress will require constant adaptation to exciting diversions and new directions.

Building on this rich history of exploration, 

we now seek to transform human understanding of this fascinating system of systems that 

are so closely connected (page 14). We will 

not only develop a predictive capability to address hazards to space travelers and important 

technological assets closer to home, but we 

will also learn how the interplay of fundamental space processes affects the habitability of 

other distant environments. The strategic plan 

for the future of heliophysics consists of three 

encompassing scientifi c and exploration objectives we designate F, H, and J for Frontier, 

Home, and Journey.

Heliophysics: The Science

Chapter 2

Earth’s upper atmosphere, the Sun, our solar system, and the universe consist primarily 

of plasma, resulting in a rich set of interacting 

physical processes and regimes, including intricate exchanges with the neutral environment. 

We will encounter hazardous conditions on our 

return to the Moon and our journey to Mars. 

Technological systems are disrupted and we 

must develop a complete understanding of the 

many processes that occur within these systems with such a wide range of parameters 

and boundary conditions.

As the foundation for our long-term research 

program, we must develop a comprehensive 

understanding of the fundamental physical processes of our space environment–from the Sun 

to the Earth, to other planets, and beyond to 

the interstellar medium. We will systematically 

examine similar processes in widely different 

regimes with a range of diagnostics techniques 

to both test our developing knowledge and to 

enhance overall understanding. The universal themes of energy conversion and transfer, 

cross-scale coupling, turbulence and nonlinear 

physics have been chosen as near-term priority targets. The fi ve fundamental processes 

that have been identifi ed as the critical immeOpen the Frontier to 

Space Environment 

Prediction

Understand the fundamental physical processes of the space environment 

- from the Sun to Earth, to other planets, 

and beyond to the interstellar medium.
26

HELIOPHYSICS

Humankind does not live in isolation; we are 

intimately coupled with the space environment 

-through our technological needs, the habitability of the planets and the solar system bodies we plan to explore, and ultimately the fate 

diate steps are magnetic reconnection, particle 

acceleration and transport, the generation and 

variability of magnetic fi elds, cross-scale coupling across boundaries and large structures, 

and nonlinear energy and momentum transport 

and coupling in atmospheres. Both in situ and 

remote sensing observations will be required, 

together with modeling to provide a three dimensional large-scale perspective as well as 

a detailed small-scale microphysics point of 

view. With our increasingly sophisticated understanding of such basic processes, we will 

open the frontier of predictive modeling across 

the solar system.

Understand the 

Nature of Our Home 

in Space

of our Earth itself. We regularly experience how 

variability in the near-Earth space environment 

affects the activities that underpin our society.

We plan to better understand our place in 

the Solar System by investigating the interaction of the space environment with the Earth 

and the effect of this interaction on humankind. 

Building on our new knowledge of fundamental processes, we plan to characterize and develop a predictive knowledge of the impact of 

the space environment on society, technology, 

and our planet. This will be accomplished both 

by direct investigation of the local environment 

and by what can be learned about life on Earth 

through studying other environments. Human 

life and society provide the context in which 

these investigations are conducted.

As we extend our robotic and human presence throughout the solar system, we will be 

increasingly interested in the planetary environments that await us and how the lessons 

learned can be applied to our home on Earth. 

Much can also be learned by studying our own 

atmosphere and applying that knowledge to 

the exploration of other planets. Even a casual 

scan of the solar system is suffi cient to discover that habitability, particularly for humankind, 

requires a rare confl uence of many factors. 

At least some of these factors, especially the 

role of magnetic fi elds in shielding planetary 

atmospheres, are subjects of immense interest. We believe we know some of the features 

that make planets habitable, but there is much 

more to be understood.

Understand how human society, 

technological systems, and the habitability of planets are affected by solar variability interacting with planetary magnetic fi elds and atmospheres.
27

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

The great variety of space environment conditions will have a signifi cant impact on our future space explorers, both robotic and human. 

We plan to pursue, with all due vigilance, the 

research necessary to assure the safety and 

the maximum productivity of our explorers. We 

plan to develop the capability to predict space 

environment conditions from low Earth orbit to 

the Moon and Mars. Addressing space weather 

issues is necessary for optimizing the design of 

habitats, spacecraft, and instrumentation, and 

for planning mission and operations scenarios, 

ultimately contributing to mission success.

Building on our knowledge of fundamental 

processes, we plan to understand those aspects of the space environment essential for 

enabling and securing space travel. Useful engineering data are already fl owing into exploration-oriented planning and implementations 

because the Heliophysics community has long 

been exploring useful scientifi c directions. Our 

heliophysics research community is poised to 

provide the next generation of measurements, 

Safeguard the 

Journey of 

Exploration

simulations, and models that will be useful to 

the implementation of manned and robotic 

missions to the Moon, Mars, and other planetary bodies. Such parameterizations of the 

space environment will be essential inputs for 

overcoming the challenging engineering problems that must be solved for successful and 

economical exploration activities.

The remainder of this chapter explains the 

research focus areas and lists the investigations that fl ow from these three objectives. 

The Connection to missions is developed in 

later chapters. See the table at the beginning 

of Chapter 4 for mission details.

Maximize the safety and productivity of 

human and robotic explorers by developing the capability to predict the extreme and dynamic conditions in space.
28

HELIOPHYSICS
29

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

Open the Frontier to Space 

Environment Prediction

Understand the fundamental physical processes of the space 

environment - from the Sun to Earth, to other planets, and 

beyond to the interstellar medium.

This results in a rich set of interacting physical processes, including intricate exchanges 

with the neutral gas in planetary atmospheres. 

Although physicists know the laws governing 

the interaction of electrically charged particles, 

the collective behavior of the plasma state 

leads to complex and often surprising physical 

phenomena.

As the foundation for our long-term research 

program, we will develop a comprehensive 

scientific understanding of the fundamental 

physical processes that control our space environment – from the Sun to the Earth, to other 

planets, and beyond to the interstellar medium. 

We must be able to predict the behavior of the 

complex systems that influence the inimical 

conditions we will encounter on our return to 

the Moon and journeys to Mars.

Objective 

The strategy for prioritizing this first science 

objective focuses on the knowledge gaps 

most vital to safe and productive exploration 

via the development of accurate forecasting 

of the space environment. Four fundamental 

processes have been identified as crucial immediate steps: magnetic reconnection, particle acceleration, the physics of plasma and 

neutral interactions, and the generation and 

variability of magnetic fields with their coupling to structures throughout the heliosphere. 

Each of these research focus areas (RFA’s) 

involves the universal themes of energy conversion and transport, cross-scale coupling, 

turbulence, and nonlinear physics – concepts 

that are fundamental to the understanding of 

space and planetary systems. In addition they 

all include processes that can be influenced by 

The Sun, our solar system and the universe 

consist primarily of plasma. Plasmas are more 

complex than solids, liquids, and gases because the motions of electrons and ions produce both electric and magnetic fi elds. The 

electric fi elds accelerate some of these particles, sometimes to very high energies, and the 

magnetic fi elds guide their motions.

The processes of interest occur in many locations, 

though with vastly different magnitudes of energy, 

size, and time. The same 

processes rule the seething 

atmosphere and interior of our Sun, the supersonic wind of particles that our star flings 

outward into space, Earth’s cocoon-like magnetosphere, the highly variable terrestrial ionosphere, the tenuous upper atmosphere of 

Mars, and even the fantastically energetic spinning pulsars that spray out beams of x rays.

By quantitatively examining similar phenomena occurring in different regimes with a 

variety of measurement techniques, we can 

ultimately identify the important controlling 

mechanisms and more rigorously test our developing knowledge. Both remote sensing and 

in situ observations must be utilized to provide 

the complementary three-dimensional largescale perspective and the detailed small-scale 

microphysics view necessary to see the complete picture.

Prediction provides the ultimate test for scientific understanding.
30

HELIOPHYSICS

Particle Acceleration: By 

far the most distinguishing 

characteristic of plasmas, in 

contrast to the neutral states 

of matter of planets, is that 

plasmas produce prodigious 

large-scale boundaries or by coupling between 

regions with very different conditions (for example, cold, dense neutral atmospheres with 

energetic particles).

Magnetic Reconnection: Magnetic reconnection occurs in highly 

localized regions when 

interacting magnetic 

fields “snap” to a new, 

lower energy configuration, as if a pair of twisted rubber bands broke and relinked to form two 

new relaxed bands. Magnetic reconnections 

can release vast amounts of stored energy and 

are responsible for solar flares, CME’s and geospace storms. An explosive release of energy 

can be potentially devastating to space assets 

and voyaging humans, and can seriously affect 

worldwide communications. Although we have 

developed an initial picture of where reconnection may occur and the observable results, the 

detailed physical mechanisms, in particular the 

microphysical processes and the role of largescale topology, are not understood. This focus 

area (RFA F.1) will deliver a fundamental understanding of this universal process in the very 

different regimes where it occurs. 

amounts of radiation. Because energetic particle radiation has the most direct impact on 

human and robotic space explorers, detailed 

understanding of the particle acceleration processes that produce radiation, the regions in 

which these processes operate, and the boundary conditions that control them is crucial to 

the exploration of space. RFA F.2 will investigate the mechanisms that accelerate particles 

within the solar system, including small-scale 

waves, shocks, and quasi-static electric fields. 

Radiation can be produced almost instantaneously through explosive processes, but also 

built up step-wise by processes acting under 

more benign conditions. Providing essential 

predictions of the radiation environment along 

the end-to-end path of space explorers will involve accounting for particle acceleration in all 

its forms and locations, from Earth’s aurora to 

the solar corona.

Plasma-Neutral Interactions: Heliophysics requires 

understanding of the fundamental physics of plasma 

and neutral particle coupling. 

This coupling encompasses 

a variety of mechanisms and regions from 

turbulence and charge exchange in the solar 

wind to electrodynamic processes in the ionosphere and thermosphere to gravity waves 

and chemical/collisional interactions in planetary atmospheres. Space plasmas are often 

in a non-equilibrium state and they can be a 

highly nonlinear medium. Many of the techniques developed for understanding nonlinear 

systems ensue from basic plasma research 

– chaos theory is one example; another is the 

understanding of turbulence, which is so important to safer air travel. The goal of RFA 

F.3 is a comprehensive understanding of how 

nonlinear processes influence plasma-neutral 

interactions from atmospheric to heliospheric 

scales. This work has specific applicability to 

the operation of satellites in the Martian atmosphere, the mitigation of the effects of global 

change, as well understanding how habitable 

planets retain their atmospheres.

Magnetic Dynamos: Understanding the variations of the 

magnetic fields of the Sun and 

planets on both long and short 

time scales is the key element 

of the Sun-Solar System 

connection addressed by RFA F.4. The creation 

of these fields – the magnetic dynamo problem 

– remains one of the outstanding problems in 

Plasmas are conductive assemblies of 

charged particles and neutrals that exhibit 

unfamiliar collective effects. Plasma systems 

carry electrical currents, generate magnetic 

fields, and can interact explosively. The solar 

system is the only directly accessible laboratory for exploring the behavior of astrophysical plasmas. We must prepare our space 

explorers to live and work in this harsh alien 

environment.
31

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

physics. How dynamos operate in such widely 

disparate systems – from stellar interiors 

to planetary cores – is poorly understood. 

Dynamos determine the characteristics of the 

solar activity cycle. The Sun’s magnetic field 

controls the structure of the heliosphere and, 

thus, regulates the entry of galactic cosmic rays 

into the solar system. Therefore, it is imperative 

that we understand the origin and variability of 

solar magnetism. The Earth’s interior dynamo 

sustains the geomagnetic field and provides the 

shield that enables life to flourish in the harsh 

radiation environment of space. Understanding 

how dynamos are created and sustained, how 

they affect the nearby space environment, how 

to predict their variations and ultimately their 

demise lies at the heart of understanding our 

own destiny.

With our increasingly sophisticated 

understanding of these fundamental physics 

process, we will open the frontier to the 

development of truly predictive space weather 

models.

Objective F: Open the Frontier to 

 Space Environment Prediction

Priority Research Focus Areas & 

Associated Investigations

F1.Understand magnetic reconnection as 

revealed in solar fl ares, coronal mass 

ejections, and geospace storms.

1. What are the fundamental physical 

processes of reconnection on the small 

scales where particles decouple from the 

magnetic fi eld?

2. What is the magnetic fi eld topology for 

reconnection at the Earth and at what size 

scales does magnetic reconnection occur 

on the Sun?

F2. Understand the plasma processes that 

accelerate and transport particles.

1. How are charged particles accelerated to 

high energies?

2. How are energized particles transported?

3. How is the solar wind accelerated and 

how does it evolve?

4. How are planetary thermal plasmas 

accelerated and transported?

F3. Understand the role of plasma and neutral 

interactions in nonlinear coupling of regions 

throughout the solar system.

1. What governs the coupling of neutral and 

ionized species at various spatial and 

temporal scales?

2. How do energetic particles chemically 

modify planetary environments?

3. How do the magnetosphere and the 

ionosphere-thermosphere systems 

interact with each other?

4. How do the heliosphere and the 

interstellar medium interact?

5. How does the neutral environment in 

planetary and cometary systems affect 

their global morphology through charge 

exchange and mass loading processes?

F4. Understand the creation and variability of 

magnetic dynamos and how they drive the 

dynamics of solar, planetary and stellar 

environments.

1. How do subsurface fl ows drive the solar 

dynamo and produce the solar cycle?

2. How do solar and stellar dynamos evolve 

on both short and long-term time scales?

3. How are open fl ux regions produced 

on the Sun, and how do variations in 

open fl ux topology and magnitude affect 

heliospheric structure?

4. How do planetary dynamos function and 

why do they vary so widely across the 

solar system?
32

HELIOPHYSICS

RFA F.1: Understand magnetic 

reconnection as revealed in solar 

flares, coronal mass ejections, 

and geospace storms.

Reconnection typically results in the rapid 

conversion of magnetic energy into particle energy. It is an important, cross-scale coupling 

process in a variety of space plasmas ranging from the magnetotail of the Earth to solar 

flares. Reconnection can accelerate particles 

to very high energies and, because it changes 

the magnetic field topology, it can dramatically 

alter the regions of space that are accessible 

to those particles. In the corona reconnection 

can sever large clouds of dense plasma from 

the magnetic fields that anchored them. Solar 

flares, coronal mass ejections, and geospace 

storms are all initiated and energized by reconnection – often with potentially devastating effects for space systems.

The explosive conversion of magnetic energy originates in a volume of space known as 

the diffusion region. This region is very small 

when compared to the large scales in space. 

For example, reconnection at the Earth’s magnetopause surface (the boundary separating 

the solar wind and terrestrial magnetic fields) 

occurs in a region with an area of the order of 

hundreds of square kilometers compared to 

a total surface area of approximately 60 billion square kilometers. While there have been 

a few encounters with the diffusion region in 

the near-Earth environment, systematic in situ

study of this region is just beginning. Current 

solar imaging is insufficient to resolve the diffusion region associated with solar flares. Thus, 

the physical processes that initiate and control 

reconnection remain to be measured.

Most of our basic theoretical understanding 

of reconnection comes from an MHD (magnetohydrodynamics) perspective. Although this 

approach has provided important insight, it is 

inherently limited in that it cannot examine the 

very small scales on which ions and electrons 

decouple from the magnetic field or predict the 

particle energization process. Important questions that remain unanswered include: What 

initiates the reconnection process? What are 

the kinetic processes that occur and what is 

their role? What is the range of scale sizes of 

the region over which reconnection occurs 

in different regimes? Is reconnection quasisteady or bursty? What mechanisms or boundary conditions control the spatial and temporal 

scales? What is the 3D structure of the reconnection region and how does this structure affect particle acceleration?

One type of reconnection takes place when the Earth’s usually impenetrable magnetic field fractures and 

has to find a new stable configuration. Until the field mends itself, solar protons leak through the gap and jet 

into Earth’s atmosphere, precipitating aurora and ionospheric currents. For a predictive capability, very high 

time-resolution, 3D measurements of particles and fields from multiple satellites with variable separations 

are needed reveal the micro- to meso-scale processes needed to directly probe the electron diffusion region. 
33

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

Granulation on the solar surface reveals Texas-sized convective cells produced by hot columns of rising gas. 

(left) The cells originate just below the visible photosphere and only last for about five minutes. The emergence of active regions disrupts this steady state and stores energy in the overlying atmosphere (center) 

Eventually this leads to dramatic energy releases from coronal loops in the form of flares and coronal mass 

ejections (right). Various acceleration mechanisms have been proposed to explain the highly efficient energy conversion in these eruptions, including strong electric fields induced by reconnection in current sheets.

RFA F.2: Understand the plasma 

processes that accelerate and 

transport particles.

High-energy particles accelerated at the Sun 

and within interplanetary space, as well as cosmic rays from outside the solar system, pose a 

serious hazard to the human and robotic exploration of our solar system. Energetic particles 

produced or trapped within planetary magnetospheres can have deleterious effects on important technological assets in those locations. 

Predicting these effects requires a fundamental 

understanding of where and how particles are 

accelerated and how they are transported.

More than one mechanism can operate to 

produce a given energetic particle population 

at a given location and the nature of the seed 

population from which the accelerated particles are drawn is a critical part of the puzzle. 

Important processes for near-term investigation include quasi-static electric fields parallel 

to the background magnetic field, wave parallel 

electric fields, stochastic (Fermi) acceleration, 

and the drift of particles along a component of 

the electric field. such as occurs in shocks and 

the magnetotail. The Earth’s aurora provides a 

unique opportunity to understand acceleration 

by parallel electric fields and waves. Particle 

acceleration at CME shock fronts is a leading 

candidate for the production of gradual solar 

energetic particle (SEP) events.

Energetic particles accelerated both at localized sites (solar flares, magnetotail reconnection sites, auroral acceleration regions), and 

globally (coronal and interplanetary shocks, corotating interaction regions and global merged 

interaction regions in the solar wind, and the 

termination shock) need to be understood. 

An understanding of the acceleration of thermal plasmas is also vital to meeting NASA objectives. For example, both the interaction of 

the Sun with planets and the transport of solar 

energetic particles are mediated by the solar 

wind. Successful progress on the understanding of solar wind acceleration will significantly 

improve the predictive capability for determining the severity of solar wind disturbances. The 

origin of the solar wind is not well understood 

and represents a large gap in our knowledge of 

fundamental processes.
34

HELIOPHYSICS

Image of electron density enhancements (equatorial arcs) in the Earth’s ionosphere. The transport of 

plasma away from the equator results in alternating 

traveling bands of enhanced and depleted density. 

These exist during the daytime and most of the night 

and create enhanced media transmission errors in 

navigation and communication signals.

RFA F.3: Understand the role of 

plasma and neutral interactions in 

the nonlinear coupling of regions 

throughout the solar system

Plasma populations are embedded in a background neutral gas throughout the solar system, from the solar transition region, to planetary upper atmospheres, to the heliosphere’s 

interface with the interstellar medium. These 

populations transfer energy and momentum 

through multi-scale, nonlinear interactions 

which act to redistribute the bulk flows that, 

in turn, feed energy back into the original coupling system.

For example, the upper atmospheres of planets, including Earth, are dramatically affected 

by energetic inputs originating at the Sun in the 

form of photons, particles, and fields. However, there are many pathways by which that 

solar energy is transformed and redistributed 

throughout the atmosphere until the energy is 

ultimately re-radiated to space. Connected 

with these processes is much of the inherent 

variability of the atmosphere over daily to millennial time scales.

The lower atmosphere is periodically pumped 

and heated, giving rise to a spectrum of smallscale gravity waves and longer-period oscillations. These waves can propagate into the 

mesosphere and thermosphere depositing 

momentum. The atmospheric mean circulation is thereby modified, resulting in changes 

to the temperature structure and redistribution of radiation absorbers and emitters. The 

mean wind and temperature structures in turn 

influence the propagation of the waves and the 

manner in which they couple the lower and upper atmosphere. Similar processes are also 

key to understanding the upper atmosphere 

weather and climate on Mars and Venus.

The ionospheric electron density distribution 

depends on thermospheric composition and 

winds, together with electric fields that can be 

generated within the ionosphere-thermosphere 

system or imposed from the magnetosphere. 

In turn, the ionospheric plasma can inhibit or 

accelerate thermospheric winds that produce 

electric fields via an electrodynamic interaction. 

The interactions and feedback mechanisms remain a mystery due to a lack of simultaneous 

measurements of all the parameters that describe the fully coupled system. These interactions can occur on a global scale, but can also 

produce mesoscale structures, such as high 

latitude thermospheric density cells that affect 

satellite orbits, or mid-latitude electron density 

enhancements that disrupt aircraft navigation 

systems being implemented by the FAA. In 

addition, smaller scale structures cause ionospheric irregularities that degrade communication system performance.

Turbulence is another example of a very important multi-scale, nonlinear process that 

transports particles and fields effectively, but 

is not well understood. Numerical simulations 

and laboratory experiments demonstrate that, 

in the presence of rotation or magnetic fields, 

turbulent motions create small-scale and largescale dissipative structures.

In addition, electrodynamic and mass coupling along magnetic fields are fundamental 

physical processes that cut across many disciplines of space science. The interface between 

the heliosphere and the interstellar medium is a 

coupling region about which we are just beginning to learn.

Finally, mass loading through ionization and 

charge exchange is a phenomenon of broad 

interest from planetary and cometary atmospheric erosion to energetic particle creation 

and loss.
35

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

The figure shows the residual solar rotation 

speed after removing the average differential rotation. The cut-away shows the surface velocity 

on the left of the disk and a cross-section of the 

interior on the right. The two figures show how 

the rotational profile changes over six months. 

RFA F.4: Understand the creation 

and variability of magnetic dynamos and how they drive the dynamics of solar, planetary and 

stellar environments.

The Sun’s variable magnetic field is the energy source for solar particle acceleration and its 

structure controls the entry of galactic cosmic 

rays into the solar system. Helioseismic data 

from SOHO and ground-based observatories 

have revolutionized dynamo theories by placing the main solar-cycle dynamo action at the 

base of the convection zone, in the rotationally 

sheared layer called the tachocline. Having 

the correct meridional circulation has proven to 

be a key ingredient for determining the length 

of the solar cycle. For the first time models 

can now use the meridional flow patterns from 

previous cycles to estimate the length of the 

next cycle. However, although these dynamo 

models can now forecast the cycle length, neither the amplitude nor details, such as whether 

the cycle will be double peaked, are within our 

predictive capability. For example, we do not 

know why the last two solar cycles have had 

relatively small maxima in the sunspot number. 

We know even less about activity cycles on 

other stars, though comparative stellar dynamo studies should reveal much about the longterm behavior of stars and the Sun. Developing the understanding of dynamo process to 

enable this kind of prediction is important for 

long-term planning for solar activity and would 

have obvious applications in trying to understand past and future periods of abnormally 

reduced solar activity and concomitant affects 

on terrestrial climate and planetary habitability.

Closer to home, reversals and other large 

variations of Earth’s magnetic field can lead to 

periods of reduced protection from the harsh 

radiation environment of space. The process 

responsible for the existence and behavior of 

these magnetic fields – the dynamo – involves 

the twisting and folding of weak fields so as to 

change and amplify them. Solving the problem 

of just how dynamos operate in such widely 

different environments, from planets to stars, 

will allow better predictions of the effects of 

magnetic field changes at both the Earth and 

the Sun. This understanding is essential to 

describing the coupled Sun-solar system connection and has important implications for the 

exploration of our solar system.

Simulated reversal of Earth’s magnetic field, with inward (blue) and outward (yellow) directed field lines. 

The location of the core-mantle boundary is evident where the structure becomes complex. We seek to 

understand the effects of such magnetic field variations on the formation and retention of planetary atmospheres. Image credit: Gary Glatzmaier, Los Alamos National Laboratory

37

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

Understand the Nature of 

Our Home in Space

Understand how human society, technological systems, and the 

habitability of planets are affected by solar variability interacting 

with planetary magnetic fields and atmospheres.

Objective 

We do not live in isolation. Our past, present, 

and future are intimately coupled to the relationship between the Earth and Sun - and with the 

universe beyond. Increasingly we are sensitive 

to changing conditions on the Sun and in the 

space environment because of our technology; 

increasingly we have a practical interest in the 

habitability of planets and solar system bodies 

we plan to explore; and increasingly we recognize how astrophysical phenomena influence 

life and climate on our home planet. Variability 

in this environment affects the daily activities 

that sustain our society, including communication, navigation, and weather monitoring and 

prediction. We are living with a star.

This context is not limiting. As we extend 

our presence throughout the solar system, 

we are interested in the planetary environments awaiting us and how the study of these 

environments can be applied to our home on 

Earth. Habitability, for humankind in particular, 

requires a rare convergence of many factors. 

These factors, especially the role of the Sun 

as a source of energy to planets and the role 

of magnetic fields in shielding planetary atmospheres, are a subject of immense importance. 

We understand some of the features contributing to make planets habitable, but key questions remain.

The interactive couplings of solar system processes, in the Sun and interplanetary space, 

with the interstellar medium, and throughout 

the near-Earth environment - require comprehensive study of these linked systems through 

a series of investigations covering these regions. Investigations of impacts on humankind must begin with the Sun, understand the 

cause of eruptive events and solar variability 

over multiple time scales, follow propagation 

and evolution of solar wind disturbances and 

acceleration and transport of energetic particles through the heliosphere to Earth, and 

finally investigate the interaction of solar radiative emission and the solar wind with Earth’s 

coupled magnetosphere-ionosphere-atmosphere system.

Four Research Focus Areas (RFAs) have 

been formulated to understand: the Sun so we 

can predict solar variability and the evolution 

of solar disturbances as they propagate to the 

Earth; the response of the coupled ionosphere, 

thermosphere, magnetosphere plasma enviTo meet this objective, Heliophysics investigates the 

interaction of the space environment with Earth and its impact on us and on our home, 

either directly or by what can 

be learned about life on Earth 

by studying other environments in our solar 

system and beyond. This effort builds on the 

understanding of the fundamental physical 

processes addressed in Objective F. Our scientific goal is to understand the web of linked 

physical processes connecting Earth with the 

space environment. Our applied goal is to protect society and its technological infrastructure 

from space hazards and understand the external drivers of long-term climate change. We 

will improve technological efficiency of future 

operational systems by exploiting our understanding of Earth and its place in space. Human life and society provide the context for our 

investigations.
38

HELIOPHYSICS

ronment and the impacts on society; the role 

of the Sun as the principal energy source in our 

atmosphere, including the impact of long-term 

solar variability on Earth’s climate; and, in a 

broader context than just the Earth, the solar 

photon and particle impact on other solar system bodies and how stellar activity and magnetic fields affect the evolution of planetary 

habitability over time.

It is not enough to study just variability and 

change due to external drivers. Coupled systems also have complex internal forcing, e.g. 

gravity waves breaking in the upper atmosphere. The internal dynamics of the nearEarth coupled systems that protect us must be 

understood, even in the absence of solar variability. The program outlined below focuses 

on both internal linkages and external forcing 

mechanisms.

Solar Variability & Heliospheric Disturbances. RFA H.1 aims to 

understand the Sun, determine how predictable 

solar activity truly is, and 

develop the capability to forecast solar activity 

and the evolution of solar disturbances as they 

propagate to Earth. It focuses on both shortterm and long-term variability. X-ray fl ares 

can immediately and severely degrade radio 

communications through ionospheric effects. 

Precursors to solar disturbances observable 

above and below the solar surface will initially 

serve as predictive tools for disruptive events. 

Coronal mass ejections that create large magnetic storms at Earth evolve signifi cantly over 

their multi-day travel time to Earth. We will 

learn how disturbances initiate, propagate, 

and evolve from the Sun to Earth and incorporate this knowledge into a predictive model of 

geoeffectiveness at Earth to enable a warning 

and mitigation system for our technological assets. Solar energetic particle events can pose 

serious threats to technological assets and astronauts in near-Earth orbit; we will learn how 

particles are accelerated in the inner heliosphere and how they propagate. We must also 

understand the long-term changes in total and 

spectral irradiance and the solar cycle variations that have signifi cant impacts on Earth’s 

climate and human society.

Objective H: Understand the Nature 

 of Our Home in Space 

Priority Research Focus Areas & 

Associated Investigations

H1. Understand the causes and subsequent 

evolution of solar activity that affects Earth’s 

space climate and environment.

1. How do solar wind disturbances propagate and 

evolve from the Sun to Earth?

2. What are the precursors to solar disturbances?

3. Predict solar disturbances that impact Earth.

H2. Determine changes in the Earth’s 

magnetosphere, ionosphere, and upper 

atmosphere to enable specifi cation, 

prediction, and mitigation of their effects.

1. What role does the electrodynamic 

coupling between the ionosphere and the 

magnetosphere play in determining the 

response of geospace to solar disturbances? 

2. How do energetic particle spectra, magnetic 

and electric fi elds, and currents evolve in 

response to solar disturbances?

3. How do the coupled middle and upper 

atmosphere respond to external drivers and to 

each other?

H3. Understand the role of the Sun as an 

energy source to Earth’s atmosphere and, 

in particular, the role of solar variability in 

driving change.

1. How do solar energetic particles infl uence the 

chemistry of the atmosphere, including ozone 

densities

2. What are the dynamical, chemical, and radiative 

processes that convert and redistribute solar 

energy and couple atmospheric regions? 

3. How do long-term variations in solar energy 

output affect Earth’s climate?

H4. Apply our understanding of space plasma 

physics to the role of stellar activity and 

magnetic shielding in planetary system 

evolution and habitability.

1. What role do stellar plasmas and magnetic 

fi elds play in the formation of planetary 

systems?

2. What is the role of planetary magnetic fi elds for 

the development and sustenance of life? 

3. What can the study of planetary interactions 

with the solar wind tell us about the evolution of 

planets and the implications of past and future 

magnetic fi eld reversals at Earth?

4. How do local interstellar conditions infl uence 

the Solar System’s space environment and what 

are the implications for the formation, evolution, 

and future of life in the solar system?
39

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

Variability in the magnetosphere, ionosphere, 

and upper atmosphere.

RFA H.2 will develop understanding of the response 

of the near-Earth plasma 

regions (magnetosphere, 

ionosphere, and thermosphere) to space weather. 

Solar Variability and 

Atmospheric Responses. RFA H.3 addresses the role of the Sun 

as the primary energy 

source for Earth’s atmosphere. We seek to 

understand not only the 

atmospheric response 

Stellar Variability and 

Magnetic Shielding. Other planets and other stars 

provide illuminating perspectives for understanding the Earth and Sun. RFA 

H.4 addresses the longterm impact of interactions 

of the solar wind with Earth, 

This complex highly coupled system protects 

Earth from the worst solar disturbances, but it 

also redistributes energy and mass throughout. 

A key element involves distinguishing between 

the responses to external and internal drivers, as well as the impact of ordinary reconfi gurations of environmental conditions, such 

as might be encountered when Earth crosses 

a magnetic sector boundary in the solar wind. 

This near-Earth region harbors space assets 

for communication, navigation, and remote 

sensing needs; even though conditions there 

can adversely affect their operation. Ground 

based systems, such as the power distribution 

grid, can also be affected by ionospheric and 

upper atmospheric changes. Investigations 

emphasize understanding the nature of the 

electrodynamic coupling throughout geospace 

(the near-Earth plasma environment), how geospace responds to external and internal drivers, and how the coupled middle and upper 

atmosphere respond to external forcings and 

how they interact with each other.

to solar variability, but also the importance of 

steady-state processes in maintaining our atmosphere. It also considers long-term climatic 

impacts of solar variability on humankind. We 

need to understand the changing inputs - both 

spectral changes in the electromagnetic radiation and changing levels of energetic particles 

throughout the atmosphere. Two fundamental 

problems are fi rst, delineating what processes 

convert and redistribute solar energy within the 

atmosphere and second, determining how this 

is accomplished. Other specifi c processes 

can have signifi cant impact on Earth’s atmosphere and climate and merit dedicated investigations. For example, the role of energetic 

particles from aurorae, the radiation belts, and 

solar fl ares on ozone chemistry in the upper atmosphere is not well understood. As another 

example, non-solar external processes, for example cloud nucleation from galactic cosmic 

rays, may affect Earth’s climate but the details 

of this impact are uncertain.

other solar system bodies, the local interstellar medium, and the study of activity on stars 

other than our Sun. We need to understand 

the role plasmas and magnetic fi elds play in 

planetary formation and in the evolution of 

planetary atmospheres because this relates to 

the ultimate habitability of planets. A particular 

goal is to understand the importance of planetary magnetic fi elds for the development and 

sustenance of life. 

The interaction between the solar wind and 

the interstellar medium has created boundaries 

that shield us from most of the hazardous galactic cosmic radiation. The properties of the 

local interstellar medium and of the solar wind 

change over the course of time. How do these 

changes affect the biospheres of planets like 

Earth? Observing activity on other stars will tell 

us how conditions change with time. One applied investigation that stems from these studies is to determine the implications of past and 

future magnetic fi eld reversals at Earth. Such 

investigations provide important opportunities 

for linkages with other NASA fi elds of study.
40

HELIOPHYSICS

RFA H.1: Understand the causes 

and subsequent evolution of solar 

activity that affects Earth’s space 

climate and environment

The climate and space environment of Earth 

are primarily determined by the impact of plasma, particle, and electromagnetic radiation 

outputs from the Sun. The solar output varies 

on many time scales: from explosive reconnection, to convective turn over, to solar rotation, to the 22-year solar magnetic cycle, and 

even longer, irregular fluctuations, such as the 

Maunder minimum. The variability is linked to 

the emergence of magnetic field from below 

the photosphere, its transport and destruction on the solar surface, and the eruption into 

the heliosphere of energy stored in the atmosphere as flares and coronal mass ejections. 

The large-scale heliosphere also modulates 

the propagation of incoming galactic cosmic 

rays. Longer-term changes that can affect 

Earth’s climate include solar total and spectral 

irradiance.

The solar wind, embedded disturbances, and 

energetic particle populations evolve as they 

travel through the heliosphere. Shocks accelerate particles and interact with other irregularities. CME’s can even interact with each other. 

Current observations generally depend only 

on near-Sun and 1 AU observations. Understanding the three-dimensional time-varying 

propagation of solar disturbances is one of the 

Sunspots and their associated magnetic fi elds follow an 11-year activity cycle. This composite image shows ten magnetic maps of the Sun observed 

approximately one year apart, from one maximum 

of activity almost to the next. As activity fades, the 

large regions disappear and only small ones generated near the surface continue to emerge, creating 

a salt-and-pepper pattern of ephemeral magnetic 

regions that persists through time. As the next cycle 

of activity picks up, the magnetic polarities of the active regions that emerge from deep inside the Sun 

are reversed. This means that although the sunspot 

number and the coronal activity have an eleven-year 

cycle, the full magnetic cycle is actually twenty-two 

years. Images: Kitt Peak telescope of the National 

Solar Observatory.

greatest challenges facing us. Understanding 

the internal configuration of the structures is 

another.

Precursors will provide useful information 

about solar and interplanetary events; however 

more complete predictive models based on 

physical principles are required. Like terrestrial 

weather, it is not yet clear how long in advance 

solar activity is predictable. Improved continuous observations of the solar vector magnetic 

field and high-resolution observations of the 

atmosphere are as critical for resolving this 

question as helioseismology is for revealing the 

subsurface conditions.

RHESSI data overlaid on a TRACE image shows 

gamma-rays (blue) and X-rays (red) thrown off by 

the hottest part of the 20 January 2005 fl are. The 

gamma rays are made by energetic protons at the 

Sun. 
41

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

RFA H.2: Determine changes in 

the Earth’s magnetosphere, ionosphere, and upper atmosphere to 

enable specification, prediction, 

and mitigation of their effects.

 

The near-Earth space environment, geospace, is unique in the solar system and central to the protection of Earth and its inhabitants. This region includes the magnetosphere, 

ionosphere, and thermosphere (MIT) bound 

together as a tightly coupled system that interacts with the neutral atmosphere below and 

the Sun and heliosphere above. The variability 

within geospace and the nearby interplanetary 

environment is our local space weather. Much 

of space weather is driven by the external processes discussed in the previous section. In 

addition, internal drivers of the MIT region, 

such as the upward propagation of gravity 

waves, greenhouse gases generated in the 

troposphere, wave-particle interactions, and 

auroral current systems, are equally important 

and must be investigated. The consequences 

of internal drivers include both the natural variability of the MIT system and anthropogenic 

effects.

Geospace is also the location of most of our 

space activities. Communication, navigation, 

Earth weather and remote sensing, emergency 

location, defense reconnaissance, and NASA 

missions are all affected by space weather. 

Space weather also causes disturbances of 

electric power grids and sensitive electronic 

systems on the ground. The technological 

systems sensitive to disturbances in geospace 

are increasing in importance and urgency to 

human society.

The electromagnetic, dynamical, and aeronomic processes that couple the inner and 

outer regimes of geospace remain unresolved. 

The exchange of mass and energy between 

these regions during both quiescent conditions and disturbed times must be understood 

before predictive capabilities, or strategies to 

mitigate adverse space weather effects, can 

be developed. Energetic solar and magnetospheric particles penetrate below the MIT domain into the middle and lower atmosphere, 

and establish the need to better understand 

the chemical and dynamical effects on the 

whole atmosphere.

Noctilucent clouds, also known as polar mesospheric clouds, are rare, bright cloud-like atmospheric phenomena visible in a deep twilight. Most 

commonly observed in the summer months at latitudes between 50° and 60°, they are the highest 

clouds in the Earth’s atmosphere, being located in 

the mesosphere at altitudes of around 85 kilometers. They are visible only when illuminated by sunlight from below the horizon while lower layers of the 

atmosphere are in the Earth’s shadow; otherwise 

they are too faint to be seen. 

These clouds are not well understood. In most 

meteorological concepts, clouds generally can not 

reach such great altitudes, especially at such low 

air pressures. It was once proposed that they were 

composed of volcanic or meteoric dust, but they are 

now known to be primarily composed of water ice. 

They appear to be a relatively recent phenomenon 

- they were fi rst reported in 1885, shortly after the 

eruption of Krakatoa - and it has been suggested 

that they may be related to climate change. Recent 

evidence also suggests that many noctilucent clouds 

today are created by water exhaust from manned 

spacefl ight, such as the Space Shuttle.

Noctilucent clouds can be studied from the ground, 

from space, and by sounding rockets, but they are 

too high to be reached by weather balloons. The 

AIM Explorer satellite, scheduled for launch in 2006, 

is dedicated to research into noctilucent clouds.
42

HELIOPHYSICS

RFA H.3: Understand the role of 

the Sun as an energy source to 

Earth’s atmosphere and, in particular, the role of solar variability in 

driving change. 

Solar energy in the form of photons and particles drives the chemical and physical structure of Earth’s atmosphere. For example, ultraviolet and even more energetic radiation 

deposited globally throughout the mesosphere 

and thermosphere are responsible for formation of the ionosphere. Also, while particles 

primarily deposit their energy at high latitudes, 

the resulting ionization, dissociation, and excitation of atoms and molecules can have a 

world wide effect due to dynamical processes 

that transport energy around the globe. Ultimately these processes combine to drive the 

temperature and chemical composition of the 

entire Earth’s atmosphere. A key example of 

how atmospheric modifi cation by the Sun affects life is stratospheric ozone, which acts as 

a human UV shield. The very existence of the 

ozone layer is a direct result of solar energy 

deposition. Nitric oxide created at higher altitudes by processes involving solar energy may 

be transported to lower altitudes where it can 

destroy ozone. The ionosphere-thermosphere 

plays an equally important role in protecting 

life on Earth, since it is the atmosphere’s shield 

against solar EUV radiation. 

Because life depends on the atmosphere and 

its climate, study of solar energy driven atmospheric variations is critically important. Solar 

energy and its changes have effects throughout the atmosphere including the troposphere 

where humans live. Despite this, the strength 

and variability of atmospheric solar energy deposition remain poorly understood. In addition, coupling processes that spread effects of 

energy deposition in altitude and latitude are 

not well understood. Addressing these issues 

requires high time-resolution spectral observations of solar energy deposition measurements 

of the atmospheric response, as well as theory 

and modeling of dynamical processes that distribute effects of solar energy.

The solar surface varies fairly 

regularly, with an average period 

of 11-years. However, if we look at 

the variation of the sunspot number 

with time, we fi nd that for a period 

of about 70 years, from A.D. 1645 to 

1715, practically no sunspots were 

observed. In other words, during 

this time the solar cycle was interrupted. This period of time is called 

the Maunder Minimum. It is one of 

several such intervals revealed in 

cosmic ray records. Other sun-like 

stars appear to have similar cycles. 

The Maunder minimum also coincided in time with an period of very 

cold weather in Western Europe 

(and perhaps all over the world). 

This era is often called the “Little 

Ice Age”. During this time it got so 

cold that rivers and lakes that were 

normally ice-free froze over and the 

snow did not melt all year round even 

at low latitudes. In the middle of the 

17th century temperatures dropped 

so low that the Baltic sea and the 

Thames River froze over regularly. 

The ice on the Thames in London 

was so thick that people organized 

winter festivals with skating parties 

and carnivals on the river. One of 

these festivals on the Thames was 

painted by the Dutch painter Abraham Hondius in December 1676.
43

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

RFA H.4: Apply our understanding of space plasma physics to the 

role of stellar activity and magnetic 

shielding in planetary system evolution and habitability. 

Plasmas and their embedded magnetic 

fi elds affect the formation, evolution and destiny of planets and planetary systems. The 

heliosphere shields the solar system from galactic cosmic radiation. Our habitable planet 

is shielded by its magnetic fi eld, protecting it 

from solar and cosmic particle radiation and 

from erosion of the atmosphere by the solar 

wind. Planets without a shielding magnetic 

fi eld, such as Mars and Venus, are exposed to 

those processes and evolve differently. And 

on Earth, the magnetic fi eld changes strength 

and confi guration during its occasional polarity reversals, altering the shielding of the planet 

from external radiation sources. How important is a magnetosphere to the development 

and survivability of life? The solar wind, where 

it meets the local interstellar medium (LISM), 

forms boundaries that protect the planets from 

the galactic environment. The interstellar interaction depends on the raw pressure of the solar 

wind and the properties of the local interstellar 

medium (density, pressure, magnetic fi eld, and 

bulk fl ow). These properties, particularly those 

of the LISM, change over the course of time, 

and change dramatically on long time scales 

(1,000 years and longer) as the solar system 

encounters interstellar clouds. How do these 

long-term changes affect the sustainability of 

life in our solar system? Understanding the nature of these variations and their consequences 

requires a series of investigations targeting the 

structure of the heliosphere and its boundaries 

and conditions in the LISM. Planetary systems 

form in disks of gas and dust around young 

stars. Stellar ultraviolet emission, winds, and 

energetic particles alter this process, both in 

the internal structure of the disk and its interaction with its parent star. The role of magnetic 

fi elds in the formation process has not been 

fully integrated with other parts of the process. 

The study of similar regions in our solar system, 

such as dusty plasmas surrounding Saturn and 

Jupiter, will help explain the role of plasma processes in determining the types of planets that 

can form, and how they later evolve.

On May 24, 2005 NASA’s Voyager 1 spacecraft had traveled far enough outward through 

our Solar System that it reached the heliosheath. This is an area just past the termination 

shock region, where the solar wind crashes into the thin interstellar gas of the galaxy.

45

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

Safeguard the Journey of Exploration

Maximize the safety and productivity of human and robotic 

explorers by developing the capability to predict the extreme and 

dynamic conditions in space. 

Objective 

Harsh conditions in the space environment 

pose significant risks for the journey of exploration. Like seafaring voyagers, space explorers 

must be constantly aware of the current space 

weather and be prepared to handle the most 

extreme conditions that might be encountered. 

The important considerations include sudden 

changes in energetic particle and electromagnetic radiation, encounters with plasmas that 

cause spacecraft charging and discharging, 

and the uncertain response of neutral atmospheres to variable energy inputs.

The first step toward safeguarding astronauts 

and robotic assets in space is to characterize 

the extremes and ranges of variability that can 

occur in the space environment to help establish appropriate design requirements for vehicles, electronics, and habitats. This requires 

not only measurements in various locations at 

different times, but also an understanding of 

the physical processes that both cause temporal fluctuations and limit the range of responses 

of the system to those inputs.

The next milestone requires the ability to determine current conditions in key locations from 

an affordable set of available measurements 

– nowcasting of the space environment. This 

provides the critical operational knowledge 

that productive work can safely be undertaken 

at the time. The set of observations must be 

carefully chosen and the physical system must 

be modeled well enough to give confidence 

that the results can be extrapolated to the relevant locations.

Finally, we must develop the capability to 

forecast the dynamic conditions in space. 

Forecasting quiet times may be as useful as 

forecasting disturbances. Initial reliance on 

empirical relationships will give way to highfidelity physics. As our understanding of the 

fundamental processes improves, through 

comparison of predictive models with actual 

events, we will gradually improve the accuracy 

and extend the range of our predictions, and 

provide key support to implementing the Vision for Space Exploration. As with terrestrial 

weather in the past several decades, progress 

will be made, but it will be difficult because the 

systems are more diverse, the measurements 

are more sparse, and the physics is more complex.

These steps are not necessarily sequential 

and some capability already exists in each 

area. One of the first major challenges is to 

determine more precisely what capabilities are 

needed and when. Our Objective J focuses 

on the science necessary to ensure safety and 

maximize productivity of both human and robotic space explorers. This objective includes 

both near-Earth and planetary environments, 

especially as they affect the robotic and technological systems that support human space 

flight. Benefits of addressing these issues 

include the optimization of spacecraft and inHumans will work with robots and vehicles on 

Mars. Safe and productive expedition activity 

will depend on accurate forecasting of surface 

and space weather conditions in order to mitigate risks but avoid false alarms. 
46

HELIOPHYSICS

strument design, improved planning of mission 

and operations scenarios, ensuring the safety 

and maximizing the success and productivity 

of both robotic and human exploration.

Though much of the dramatic variability in 

the space environment is driven by solar activity, such as flares and coronal mass ejections 

or energetic particles accelerated by shocks 

in the heliosphere, understanding the more 

routine variations driven by rotation or slowly 

evolving structures is also important. For example the changing density of the Martian upper atmosphere depends on many uncertain 

factors in addition to solar activity. The underlying thread that links all three of the Heliophysics roadmap objectives is working to achieve 

a detailed understanding of the basic physical 

processes required to enable prediction. While 

Objective H focuses on the science needed to 

understand the processes in the near-Earth 

space environment that affect life and society, Objective J emphasizes understanding 

the variability of the space environment and its 

potential hazards with the purpose of enabling 

and securing human and robotic space travel 

across the inner solar system.

Objective J is divided into four priority Research Focus Areas (RFAs). The first aims to 

adequately characterize the important environments. The second and third build on the first 

and focus on developing the capability to predict solar activity and understand the propagation and evolution of consequential events in 

the inner heliosphere. The final RFA targets the 

environmental variability at planets (Earth and 

Mars) that impact exploration activities.

Characterization of Space 

Environments. RFA J.1 focuses on determining the 

full range of extreme conditions that may occur in the 

inhospitable environments 

that human and robotic 

explorers will encounter. 

Learning these limits takes 

more than just observational surveys; it requires 

basic understanding of the dynamics of each 

space environment. This entails developing 

an understanding of the internal mechanisms, 

the critical boundary conditions, and the exterObjective J: Safeguard the Journey of 

 Exploration

Priority Research Focus Areas & 

Associated Investigations

J1. Characterize the variability, extremes, and 

boundary conditions of the space environments 

that will be encountered by human and robotic 

explorers.

1. What are the variability and extremes of the radiation and space environment that will be encountered 

by future human and robotic explorers, both in 

space and on the surface of target bodies?

2. How does the radiation environment vary as a 

function of time and position, and how should it be 

sampled to provide situational awareness for future 

human explorers?

3. What is the relative contribution to the space radiation environment from solar energetic particles and 

galactic cosmic rays and how does this balance 

vary in time?

J2. Develop the capability to predict the origin and 

onset of solar activity and disturbances associated with potentially hazardous space weather 

events.

1. What are the observational precursors and magnetic confi gurations that lead to CMEs and other solar 

disturbances, and what determines their magnitude 

and energetic particle output?

2. What heliospheric observations, and empirical models are needed to enhance the predictive capability 

required by future human and robotic explorers?

J3. Develop the capability to predict the propagation and evolution of solar disturbances to enable safe travel for human and robotic explorers.

1. How are solar energetic particles created and how 

do they evolve from their coronal source regions 

into interplanetary space?

2. How do solar magnetic fi elds and solar wind plasma 

connect to the inner heliosphere and what is the nature of the near-Sun solar wind through which solar 

disturbances propagate?

3. How are energetic particles modulated by largescale structures in the heliosphere and what determines the variations in the observed particle fl uxes?

J4. Understand and characterize the space weather 

effects on and within planetary environments to 

minimize risk in exploration activities.

1. To what extent does the hazardous near-Earth 

radiation environment impact human and robotic 

explorer’s safety and productivity?

2. What level of characterization and understanding 

of the dynamics of the atmosphere is necessary to 

ensure safe aerobraking, aerocapture and EDL operations at Mars?

3. To what extent do ionospheric instability, seasonal 

and solar induced variability affect communication 

system requirements and operation at Earth and 

Mars?

4. What are the effects of energetic particle radiation 

on the chemistry and the energy balance of the 

Martian atmosphere?

5. What are the dominant mechanisms of dust charging and transport on the Moon and Mars that impact 

human and robotic safety and productivity?
47

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

nal drivers – the sources of external variability at the Sun and the interplanetary medium 

that modulates its extremes. This knowledge 

feeds into the design of exploration activities 

and equipment. Practical understanding of the 

physical conditions and processes that modulate various space environments will lead to a 

capability to nowcast and forecast both benign 

and hazardous intervals.

Prediction of Hazardous 

Solar Activity. RFA J.2 

aims to develop the capability to forecast solar activity and the onset of the 

solar disturbances that 

are sources of potentially 

hazardous space weather. 

Successful prediction begins with reliable characterization of impulsive 

solar disturbances and their global effects on 

the corona and solar wind through which they 

propagate. Presently solar fl ares and CME’s 

are little more predictable than earthquakes or 

volcanic eruptions. Complex active regions 

and other features with high potential for eruption can be identifi ed on the visible solar disk 

and, absent such regions, it is quite feasible 

to announce “all clear” periods, when sensitive 

activities can be safely accomplished. However, during most of the 11-year solar activity 

cycle, when active regions are almost continuously present or could emerge at any time, 

even short-term forecasting is unreliable with 

our current level of knowledge. On longer time 

scales, we need to develop the ability to predict when and where active regions will arise, 

when the magnetic fi eld will become unstable, 

and what the heliospheric consequences will 

be. This requires spacecraft observations of 

the entire solar surface both to follow the evolution of active regions over the full solar disk 

and to observe complex active regions that 

may be magnetically connected to human or 

robotic explorers far from Earth.

Propagation to Explorers. 

RFA J.3 entails development of an understanding 

of coronal and heliospheric 

acceleration mechanisms, 

the propagation of solar 

disturbances, and local acceleration of particles by plasma interactions 

in the disturbed solar wind. All are needed for 

a practical predictive understanding of these 

events. Disturbances interact with the solar 

wind. Particles and fi elds can be swept up and 

shocks associated with CME’s can accelerate 

particles to dangerous energies. We need to 

develop observational and modeling tools to 

more accurately predict the arrival times, durations, and severity of solar energetic particle 

impacts. In addition, exposure to high-energy 

galactic cosmic rays accumulates over long intervals to dangerous doses. Cosmic rays are 

modulated by the large-scale fi eld and diverted 

by disturbances in the outer heliosphere, so 

they are of less concern during intervals of high 

solar activity. 

Space Weather Effects 

on Planets. Hazards in 

planetary environments 

must also be understood, 

characterized, and mitigated. RFA J.4 targets 

how space weather impacts planetary environments in ways that affect exploration activities, such as spacecraft 

staging in low Earth orbit, or entry, descent, 

and landing (EDL) at Earth and Mars. Reliable 

communications and navigation for spacecraft 

and surface crews will require improved understanding of terrestrial and martian ionospheres. 

While the Sun and its variability drive these 

environments, many internal processes must 

also be understood. Planetary space weather 

develops through the interaction of the solar 

wind with the planetary magnetic fi elds and 

plasmas, the interaction of solar photons with 

plasma and neutral gas populations, interactions with the lower atmosphere, and via internal processes such as dynamos, wave interactions, magnetic reconnection, electric fi elds, 

transport, and chemistry. Because geospace 

is the site of initial staging activities and transport of human and robotic explorers, as well as 

their return to Earth, understanding this environment is particularly important.
48

HELIOPHYSICS

RFA J.1: Characterize the variability, extremes, and boundary conditions of the space environments 

that will be encountered by human 

and robotic explorers.

Mitigating future risks to long-duration space 

flight requires knowledge of two elements for 

operational planning: the anticipated background environment and the worst-case transient event environment. The primary goal 

of space environment characterization is to 

establish the range of variability both for system design purposes as well as to develop 

and refine comprehensive models for predictive capabilities. This characterization must be 

conducted over a sufficiently long time frame. 

We also need to be able to nowcast the space 

environment in real time, so astronaut explorers can react to current conditions.

Energetic particles from the Sun generally 

propagate along the spiral magnetic field embedded in the solar wind. However, CMEs 

routinely disrupt the field lines and solar wind 

flow. Further complicating our understanding of this relatively straightforward view are 

recent observations of significantly elevated 

proton levels without any activity observed on 

the Earth-facing side of Sun. Activity on the 

far side of Sun can have effects throughout the 

inner heliosphere. Future spacecraft in transit 

to Mars will endure a 6-9 month cruise phases 

far from either Earth or Mars, requiring them 

to have their own support, characterization, 

and forecasting capability at their own, remote 

location, independent of Earth-local forecasting. Measurements from a wide range of heliospheric longitudes will be required to accurately characterize, and ultimately predict the 

conditions throughout this region of the inner 

solar system.

Understanding the near-Sun source region 

of the space environment is ultimately required 

to provide the boundary conditions to enable 

accurate predictive modeling. This region produces solar energetic particles with energies as 

high as 1 GeV/nucleon. Above 15 solar radii, 

the solar wind speed is higher than any of the 

embedded wave speeds, so it is not possible 

to extrapolate back from in situ measurements 

made outside this region to determine the 

physical mechanisms at work there. A nearSun mission is the only way to provide the direct observations necessary to understand the 

physics of this critical region.

The continuous galactic cosmic ray background radiation is modulated by the heliosphere. Progress in understanding the modulation requires measurements far from the 

ecliptic plane and from the inner and outer 

reaches of the heliosphere.

Because the near-Earth geospace region 

is the launch and staging point for outbound 

missions, the landing point for return missions, 

and the site of much of our space-based communications and logistical infrastructure, characterizing the variability of extremes of the 

hazardous radiation environment within the 

Earth’s magnetosphere is critically important 

for safeguarding exploration activities. For example, we are currently unable to distinguish 

among a growing number of theories relating 

to the function and evolution of new radiation 

belts, how energetic and hazardous they can 

become, or the relative importance of several 

particle acceleration and loss mechanisms. 

After a day on the lunar surface, Apollo 17 astronaut 

Gene Cernan communicates with ground controllers 

from inside the lunar module Challenger. Note the 

condition of his spacesuit and the smudges of dust 

on his face. Photo credit: Jack Schmitt.
49

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

RFA J.2: Develop the capability to 

predict the origin and onset of solar activity and disturbances associated with potentially hazardous 

space weather events. 

The energetic particles in impulsive solar particle events produced near the Sun by flares or 

by coronal mass ejections in the low corona 

have 1 AU transit times of minutes to hours, 

whereas the gradual events associated with interplanetary CME shocks arrive hours or days 

later. Coronagraph observations of a CME 

leaving the Sun may give 1-2 days warning 

of the gradual events. To give warning of the 

near-relativistic impulsive events or to increase 

the warning time of CMEs and gradual events 

will require the capability to forecast the origin 

and onset of solar activity and disturbances 

from observations of the Sun itself. Successful forecasting of space weather depends on 

knowledge of solar disturbances as well as the 

global corona and solar wind through which 

they propagate. This RFA focuses on the onset of solar activity; the next RFA focuses on 

the propagation of the solar disturbances.

We already have some empirical understanding of the regions that generate solar activity: 

large, complex active regions are likely to produce flares and CMEs. Both CMEs and flares 

are driven by magnetic energy release, but 

neither the stabilizing mechanism allowing energy to accumulate, nor the release processes 

are understood well enough to predict eruption reliably. At present, the best indicators of 

oncoming geoeffective coronal disturbances 

are morphological. New physical diagnostic 

measurements in the photosphere, sub-photosphere, and solar atmosphere may hold the 

key to more reliable prediction. We need to develop the ability to predict the evolution of active regions and CME-producing regions from 

observations of the solar and corona magnetic 

fields. We need to understand how changes in 

the magnetic configurations lead to flares and 

CMEs.

Another critical need for exploration will be 

the capability of predicting “all clear” periods 

when extravehicular activities (EVAs) can be 

safely accomplished. This will require spacecraft observations of the entire solar surface, 

both to follow the evolution of active regions 

that are otherwise hidden on the back side of 

Sun and to observe complex active regions 

that may be magnetically connected to human 

or robotic explorers far from the Earth-Sun line. 

On a longer time scale, we need to develop the 

ability to predict when and where active regions 

will arise. This will require development of helioseismology techniques and also observation 

of the Sun from multiple view points. Research 

focus areas from Objective F provide the foundation for understanding the fundamental processes related to long term variations in solar 

activity.

In order to develop the methodology and 

tools required during the first human exploration operations on the Moon, presently scheduled near the solar maximum of 2020, these 

investigations need to begin at or just after the 

time of the next solar maximum (2011-2015).

One of the most diffi cult problems in space 

weather is the prediction of solar energetic particles. These relatively rare events travel from 

the Sun to Earth in about an hour, giving astronauts and spacecraft operators little time to 

prepare. New theoretical models are providing 

information about the precise source region of 

the energetic particles. Instead of blasting outward from the fl are itself, many of these particles may arise in a thin electrifi ed sheet of gas 

that stretches from the fl are site to the base of 

the coronal mass ejection. This current sheet 

acts much as a particle accelerator, pushing 

atomic particles to almost the speed of light.
50

HELIOPHYSICS

RFA J.3: Develop the capability to 

predict the propagation and evolution of solar disturbances to enable safe travel for human and robotic explorers.

Predicting the heliospheric radiation environment requires an understanding of how solar 

energetic particles (SEPs) are produced, how 

solar disturbances evolve as they propagate 

outward, and how solar disturbances modulate galactic cosmic rays. The investigations 

described below, along with the fundamental 

physical understanding provided by the Objective F investigations, are the necessary steps 

required for transitioning to predictive understanding.

Solar energetic particles can be grouped 

into two classes: impulsive events and gradual events. Impulsive events are associated 

with fl ares or current sheets in CMEs. Gradual events are associated with CME shocks 

and some are produced farther out in the heliosphere by corotating interaction regions 

(CIRs). Gradual events produce greater risks 

to explorers because they extend tens of degrees in latitude and longitude and can last for 

days as a disturbance propagates through the 

interplanetary medium. We must characterize 

the coronal and interplanetary SEP source regions and the properties of the resulting SEPs 

in order to understand the important factors 

that determine their composition, fl ux, energy 

spectrum, and duration. In situ measurements 

within 0.3 AU are needed in order to characterize the particles before they are scattered in 

the interplanetary medium.

The evolution of solar disturbances depends 

on the pre-existing state of the solar wind and 

the background magnetic fi elds through which 

they propagate. Knowledge of the bulk properties of the solar wind is important for determining the strengths of shocks involved in energetic particle acceleration. On smaller spatial 

scales, wave turbulence processes play a role 

in particle heating and acceleration. Remote 

sensing measurements, both spectroscopic 

and imaging, can tell us much about the region nearest the Sun. However, the regions 

of the outer corona that provide the interface 

between the inner corona and the heliosphere 

(solar wind) are best studied with direct in situ

measurements. In situ measurements taken 

more than about 0.1 AU from the Sun cannot 

be extrapolated back to determine the physical mechanisms at work in the coronal source 

regions. Understanding the physics of these 

critical regions is necessary to predict the radiation environment throughout the solar system.

Galactic cosmic rays (GCRs) and other energetic particles are affected by disturbances in 

the heliosphere. The outer heliosphere shields 

us from much of the nearly continuous GCR 

fl ux, as much as 90% at 100 MeV/nucleon. 

The remaining fl ux is modulated by variations 

in heliospheric structure over the solar cycle 

and by sporadic events such as coronal mass 

ejections. Near Earth substantial variability 

(factors of up to 10 over the solar cycle) is observed in the differential fl uxes of GCRs with 

energies below several hundred MeV/nucleon. 

The modulation is not completely understood. 

Global measurements of the heliospheric structure with concurrent measurements of in situ

energetic particle fl uxes are needed. In particular, missions that travel outside of the ecliptic 

plane and to the inner and outer reaches of the 

heliosphere provide essential boundary conditions necessary to constrain models.

Martian Sunset
51

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

RFA J.4: Understand and characterize the space weather effects 

on and within planetary environments to minimize risk in exploration activities. 

Human and robotic exploration of our solar 

system will necessarily be infl uenced by the 

planetary environments encountered. Both the 

plasma and neutral atmospheres of the planets, including Earth and Mars, impact exploration activities. Surface-to-orbit and surface-tosurface communications are sensitive to space 

plasma variability. Spacecraft control in low 

orbits and aerobraking parking orbits depend 

on the upper atmospheric density. Asset staging and operations, as well as astronaut health 

and safety, are impacted by planetary radiation 

environments. The radiation environment at 

the Moon varies as it traverses in and out of 

the Earth’s magnetosphere. The plasma and 

ultraviolet radiation environment at the Moon’s 

surface contributes to recognized problems 

with lunar dust.

Planetary environmental conditions develop 

through the interaction of the solar wind with 

the planetary magnetic fi elds and plasmas as 

well as through the interaction of solar photons with plasma and neutral populations and 

with the atmosphere below. To understand the 

planetary conditions essential for exploration, 

scientifi c investigations target the “near-planet” environments of the Earth and other planetary systems. Because initial staging activities 

and transit of human and robotic explorers will 

occur in geospace, including at the Moon, understanding of this environment is particularly 

important. Furthermore, near-Earth characterization and understanding provides an essential baseline for modeling the impact of space 

weather in other planetary environments. As 

exploration proceeds at other planets, our understanding of the near-Earth environment will 

guide the development of follow-on planetary 

missions. In addition, comparison with other 

planetary environments will inform our understanding of our home planet. Understanding 

and characterizing the effects of near planet 

interactions and environments is essential to 

maximize the safety, productivity, and risk mitigation of hazardous conditions for exploration 

activities. A human mission to Mars will require 

some combination of both orbiting and landing 

crews. Improved knowledge of the Mars atmosphere for aerocapture, entry, descent, and 

landing and improved knowledge of densities 

in the aerobraking regime (90 - 170 km), and 

The atmospheric density encountered by the Mars Global Surveyor mission during its aerobraking phase. 

The density varied by an order of magnitude relative to the predictions, illustrating why current atmospheric 

prediction science makes for a very tricky implementation of aerobraking and aerocapture. MGS required far 

more thruster operation than anticipated as a result of this uncertainty in atmospheric drag, and may have 

suffered minor damage to appendages. Human landings on Mars will require signifi cantly better knowledge 

of its atmospheric structure and dynamics to minimize fuel consumption while assuring safety. 
52

HELIOPHYSICS

in a possible low-altitude (200-300 km) station orbit are all required for safe operation of 

spacecraft.

Reliable communications and navigation between orbiting and surface crews, and with 

Earth, are essential, requiring improved understanding of the Martian ionosphere. Neutral 

density variability at aerobraking altitudes is 

predominantly controlled by dynamical infl uences from below and can be addressed by 

extending the same basic connections and 

measurements to higher altitudes. 

Orbiting crews may be affected by various 

space weather effects involving interaction between the solar wind and the partially-magnetized ionosphere and exosphere of Mars. For 

example, energetic particle events are of concern for astronaut safety, and the variability of 

radiation dosage when at the surface is poorly 

constrained.

The lunar surface that is encountered by the 

human and robotic explorers contains fi ne dust 

grains. Due to the lack of any appreciable atmosphere, the grains are exposed to a plasma 

and solar ultraviolet radiation environment. 

This creates a known problem of dust grain adhesion on astronaut suits and instrumentation 

that is not fully understood or resolved.

The radiation dose to astronauts during the Apollo era missions is plotted with the sunspot count. This plot 

graphically highlights the profound difference between short Apollo-like expeditions to the Moon and the 

longer duration stays anticipated as part of the Vision for Space Exploration, where sporadic risks will become certain events. 
Chapter 3.

Heliophysics: The Program
54

HELIOPHYSICS

Table 3.1. 

 The Heliophysics Program
55

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

The science and exploration prospectus in 

the previous chapter describes a crucial sector of the NASA Science Mission Directorate. 

Heliophysics research will develop knowledge 

that transforms our physical understanding of 

the universe and our place in it. Heliophysics 

investigations provide practical understanding and measurements of areas that affect our 

technological society and enable safe and productive exploration of the Moon, Mars, and beyond. The missions and technology developed 

to explore the solar system ultimately contribute to the science aspirations of the entire directorate.

The NASA strategic objective addressed 

with this roadmap is intrinsically one of connections, of infl uences that extend over vast 

distances and that produce dramatic effects 

throughout the solar system. Because these 

connections are generally mediated extremely 

locally by essentially invisible agents – plasmas 

and magnetic fi elds – investigation of the unknown processes at work across this system 

requires three approaches: a) detailed observations of the key unknowns within the system, 

b) simultaneous observations of the important 

source and interacting regions across the Solar System, and c) modeling and theory on all 

scales.

The Heliophysics program is constructed to 

address the most important fundamental Sunsolar system science problems with investigations prioritized in order to have the greatest 

impact on developing understanding of the 

entire system, from the solar sources to their 

ultimate consequences.

Heliophysics: The Program

Chapter 3

Table 3.1. The Heliophysics Program. The fi gure on the opposite page illustrates the prioritized mission set 

for heliophysics. The top panel shows the missions recommended for the Solar Terrestrial Probe and Living 

With a Star programs. The center panel (with years) shows the critical Explorer missions (purple) and the 

unfunded Flagship missions (green) and Partnership missions (yellow).

 With fairly optimistic assumptions about the Heliophysics budget, the anticipated achievements described in this chapter can be accomplished when required. Science return will be multiplied because of 

mission synergy. The missions in blue have already begun development. Future missions are shown in 

green.

 The bottom panel shows the endorsed schedule for the STP and LWS programs assuming the current 

budget level. This scenario delays many achievements and greatly curtails the ability to simultaneously 

observe the connected system. Several decision points for future missions are indicated.

 Smaller boxes indicate less costly missions. The program elements are discussed in more detail in this 

chapter. Individual missions are described in the next chapter.

 NASA’s Strategic Objective for Heliophysics

 Explore the Sun-Earth system to understand the Sun and

 its effects on Earth, on the Solar System, and on the

 space environment conditions that will be experienced by

 explorers, and demonstrate technologies that can

 improve future operational systems.
56

HELIOPHYSICS

Careful management of the resources available to address these problems points to a 

three-prong implementation strategy. First, 

science focused missions must be deployed 

to solve the fundamental physical problems 

identifi ed as key impediments in understanding how magnetic and gravitational physical 

processes operate. Second, these targeted 

science missions should be strategically ordered to ensure that complementary measurements are taken at a suffi cient number of locations. Finally, data from multiple sources must 

be synthesized through analysis, modeling, 

and theory to develop scientifi c understanding 

and practical knowledge of the system-wide 

behavior as solar storm erupt. In this way, the 

science of Heliophysics can be most effi ciently addressed with platforms deliberately and 

strategically distributed throughout the important interaction regions.

In recent years the power of simultaneous 

observations at multiple vantage points has 

been clearly demonstrated by what we now 

call the Heliophysics Great Observatory (page 

6). The current Heliophysics Great Observatory is a fl eet of widely deployed solar, heliospheric, geospace, and planetary spacecraft 

that are working together to help understand 

solar activity and its interaction with geospace 

and other planetary systems throughout the 

solar system. Like NOAA’s system for observing and predicting terrestrial weather, this observatory utilizes all assets available – remote 

sensing, in situ measurements, theory, data 

analysis, and models – to provide physical understanding and predictive capability for space 

weather research. The diverse measurements 

The Heliophysics Roadmap derives from the U.S. National Objectives and Vision and draws on earlier strategies developed by NASA and by the National Research Council for the study of the Sun-Earth Connection 

and Sun-Solar System Connection. These elements of strategy help defi ne the science that is most vital, 

compelling, and urgent. Plans for achievement in each area depend on scientifi c technical, and fi nancial 

resources. The recommended implementation prioritizes the program to provide the necessary capabilities 

when needed.
57

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

The intersecting ovals illustrate the intersection of three categories of science: scientifi c understanding 

that is enabled by exploration, science that transforms our knowledge, and science that informs to enable 

exploration. At the intersection is the ‘sweet spot’ where the highest priority Heliophysics missions lie. 

The mission acronyms are explained in Chapter 4.

across distributed spatial scales are linked by 

a variety of improving models that serve to fi ll 

in the gaps in the observations and provide 

the knowledge that will lead to predictions of 

tomorrow’s space weather. The opportunity 

exists now to deliberately evolve this distributed observatory to meet the needs of 

the Vision for Space Exploration. This is the 

Heliophysics community’s highest priority.

The strategy presented in this document has 

been derived from the NASA Objective for Heliophysics that addresses the vital, urgent, and 

compelling space weather needs of our nation. 

The community-based Heliophysics Roadmap committees solicited input from the many 

stakeholders of the program, both internal and 

external, in formulating the plan. The proposed 

Heliophysics Program implements the best 

science and exploration effort that can be accomplished within the budget constraints of 

the program. This Community Roadmap presents two alternatives, one that fi ts within the 

Prioritized Implementation Strategy

The interplay of exploration, discovery, and 

understanding provides guidance for prioritizing the program elements. Exploration of Mars 

and other destinations in the solar system provides the opportunity to measure conditions in 

different environments that help us understand 

our own world. New physical understanding 

of the Sun and its interactions with planetary 

magnetospheres provide information about the 

habitability of worlds near other stars. Understanding our space environment to the point 

expected resource cap with some specifi cally 

identifi ed augmentations, and another that is 

optimized to address the science goals in a 

more reasonable time frame with greatly increased mission synergy. The program is highly responsive to the requirements for the Vision 

for Space Exploration and consistent with the 

recommendations of the relevant decadal surveys of the National Academies and previous 

Roadmaps (See Appendix C).
58

HELIOPHYSICS

of prediction contributes to developing future 

operational systems that support the needs of 

our increasingly technological society and informing of our future exploration endeavors.

The objectives, research focus areas, and investigations defi ned in the previous chapter describe realms of scientifi c inquiry that will take 

decades to complete. The road to progress 

has been more clearly charted by identifying a 

series of targeted outcomes necessary to accomplish the desired objectives. The targeted 

outcomes in the accompanying achievements 

table have been established after careful consideration of the research focus areas, consolidation of investigation requirements, anticipation of the capabilities likely to be available and 

required at different times, and estimation of 

available resources. The outcomes have been 

ordered in phases to develop the scientifi c understanding necessary to support the needs of 

Table 3.2. Each anticipated achievement in this table has been developed from the Heliophysics research focus areas. Each targeted outcome requires advances in understanding of physical processes. Measurement 

capabilities must be available to develop that knowledge. Deployment of missions, development of theoretical 

understanding, and availability of infrastructure systems are required to provide that measurement capability. 

For each outcome in the table the necessary understanding, capabilities, and implementation have 

been traced. These scientifi c fl ow-down charts are available at the Heliophysics 2005 Roadmap web 

site (http://heliophysics.gsfc.nasa.gov/roadmap.htm) and an example chart will be found in Appendix C. 

The requirements in the numerous fl ow-down charts often overlap; so the results have been consolidated. The phasing was determined by the urgency, importance, and cost. Finally a balanced set of missions was chosen to address the most critical science and exploration topics in each phase. The missions have been assigned to program elements and resources identifi ed to implement them. Information 

gained in earlier missions must be used to decide the selection and ordering of later fl ight opportunities.

Anticipated Heliophysics Science and Exploration Achievements
59

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

society and the exploration program. 

The Heliophysics objectives identify robust 

goals that are vital, urgent and compelling. Obviously no unique strategy can exist today that 

addresses the scientifi c and programmatic 

needs, fi ts within the anticipated budget profi le, and anticipates all developments over the 

next 30 years. The developing requirements of 

the Vision for Space Exploration, the increasing need for understanding external infl uences 

on our home planet, and the transformational 

science required to develop predictive capabilities for the space environment require a broad 

approach to address interlocking needs and 

demand considerable fl exibility in the implementation. 

The program relies on several elements: 

strategically planned missions in the Solar Terrestrial Probes (STP) and Living With a Star 

(LWS) lines to address widely recognized critical problems; competitively selected Explorers 

to optimize responsiveness to strategic needs; 

coordinated operation of new and existing 

space assets as part of the Heliophysics Great 

Observatory; support for the low cost access to 

space program for unique science, community 

health, and instrument development needs; 

technology development; supportive, targeted 

research, theory, and analysis programs; and a 

strong effort in education and public outreach. 

Partnerships with other areas of NASA and 

other agencies, both U.S. and international, 

are essential. Each of these program elements 

is described in more detail below.

Flagships missions address very diffi cult 

problems in scientifi c areas that present major roadblocks to future progress. Flagship 

missions have great promise for scientifi c 

advance, but may cost four or more times as 

much as an Explorer mission. Missions of this 

scope cannot be accomplished within the current resource limits without fatally compromising the rest of the program. Flagship missions 

are identifi ed separately as top priorities for 

supplemental funding.

Science by Phase

The Roadmap committees considered three 

decade-long phases in formulating a plan. The 

achievements of each phase inform decisions 

made about implementation in subsequent 

phases. The phases roughly correspond to development cycles in the Exploration Initiative. 

Phase 1 ends in 2015 and includes missions 

launched by that date; Phase 2 ends in 2025 

and Phase 3 in 2035. The potential achievements identifi ed in Table 3.2 correspond fairly 

well to these phases.

In this section the overall program for each 

decade-long phase is summarized. Subsequent sections provide the rationale for the 

ordering of each element of the Heliophysics 

program. The illustration at the beginning of 

this chapter (Pg. 54) shows the Strategic Mission Roadmap for Heliophysics.

Our Phase 1 program presumes the continued operation of the current missions in the 

Heliophysics Great Observatory. Because of 

resource constraints, the “Current Resources” 

baseline Phase 1 program necessarily includes 

only those missions that are already in development or formulation (shown in green). These 

are STEREO, Solar-B, and MMS in the STP 

program; SDO and RBSP in the LWS program; 

and the selected Explorers: AIM, THEMIS, and 

IBEX. The selection of future Explorers will 

close gaps in the program. Of the partnership 

missions, the Pluto-Kuiper mission has already 

been launched and the Jupiter Polar Orbiter 

(Juno) is in the study phase. A solar sail demonstration mission and the ADAM Mars Scout 

mission could also occur in Phase 1. 

The recommended Phase 1 strategy optimizes the program, moving up the STP mission MMS by two years and launching the 

missions identifi ed for early in Phase 2 sooner 

- in time to allow simultaneous observation of 

related system elements. The multiple synergies and comprehensive views afforded by the 

Heliophysics Great Observatory now and as it 

evolves and develops during this interval are 

a testimonial to the investments and achievements of the past decade in Sun-Earth Connection science at NASA. The fi rst crucial set of 

questions required to open the frontier to space 

weather predictions, understand the nature of 

our home planet, and safeguard our journey of 

exploration have been largely anticipated in the 

existing program plan. Heliophysics is clearly 

poised to make signifi cant progress in the next 
60

HELIOPHYSICS

10 years on these important objectives.

Solar Probe should be launched in this 

phase, though data from this fl agship mission’s 

fi rst plunge through the solar corona will not be 

available until Phase 2. This set of investigations provides a very powerful tool for accomplishing the achievements listed in Table 3.2.

Phase 2 includes missions scheduled for 

launch between 2015 and 2025. GEC and 

MagCon address the next set of fundamental 

problems in the STP program. They too depend on continued context observations from 

the evolving Heliophysics Great Observatory. 

The LWS Program plans to launch two missions relatively early - ITSP and the Inner Heliosphere Sentinels. These rely on continuous 

measurements from SDO and RBSP to realize 

their full potential. Later two smaller missions, 

SEPM and Heliostorm/L1 will address questions about hazardous space weather directed 

toward the Earth-Moon system in support of 

the human fl ight initiative. Toward the end of 

Phase 2 a choice between terrestrial and heliospheric mission priority will need to be made 

(as described in the next section). The pace of 

launches is somewhat slower and the comprehensive coverage of the connected system 

available early in phase 2 will likely diminish 

toward the end of the decade if missions do 

not continue to function past their expected life 

times.

Missions beyond 2025 in Phase 3 have been 

identifi ed because we already know many of 

the scientifi c questions that will probably remain unanswered. The priorities will be adjusted depending on what is learned and on 

progress in the Exploration Initiative, but it is 

clear that constellations of spacecraft will be 

required in new regions to resolve spatial and 

temporal changes in the magnetosphere and 

in interplanetary space where remote global 

sensing is not possible. Technological development and selection of Explorers may allow 

some objectives to be achieved earlier.

Several missions of great interest cannot be 

implemented even during this time period. A 

few are limited by technology, but more are 

limited by resources, particularly those having 

to do with comparative magnetospheres and 

planetology.

The Heliophysics Roadmap promises signifi cant accomplishment. Most of the science 

requirements derived from the national objectives for NASA can be accomplished with the 

resources available. With additional resources 

an optimized plan has been crafted that will be 

signifi cantly more productive. The near term 

course is clear and decision points for the future have been identifi ed.

 

Program Elements

The implementation of the Heliophysics Program is currently funded though several sources. Missions come from the Solar-Terrestrial 

Probes Program, the Living With a Star Program, and the Explorer Program. The fl eet of 

existing missions makes up the Heliophysics 

Great Observatory that evolves as new missions are launched and new combinations of 

observations can be made. Larger fl agship 

missions are not part of the baseline funded 

program and Heliophysics requires additional 

resources to overcome the roadblocks to scientifi c progress in these areas. Rockets and 

balloons provide low-cost rapid access to 

space. Focused research and analysis programs lead to new understanding and contribute to new investigation requirements. The 

Table 3.3. Schematic illustrating a decision point for selecting a future STP mission.
61

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

at NASA that are refl ected in the objectives 

derived in this Roadmap and in the reduced 

funding available for this line. STP missions 

currently in development or formulation are 

STEREO, Solar-B, and MMS. The fi rst STP 

mission, TIMED, was launched in 2001 to study 

the infl uences of the Sun and of humans on 

the mesosphere and lower thermosphere/ionosphere. These missions strongly support the 

current objectives explained in this Roadmap 

and must be completed as scheduled. SolarB is a joint mission with the Japanese space 

agency, JAXA, and it will provide the high-resolution solar observations needed to understand 

magnetic energy storage and release in the solar atmosphere. STEREO will observe coronal 

mass ejections and other structures moving 

in the interplanetary medium from two spacecraft in solar orbit to understand how CME’s 

reach Earth. The set of four MMS spacecraft 

will probe the regions of geospace most critical 

to measuring magnetic reconnection.

In order to support the fundamental science 

necessary to open the frontier for prediction of 

space weather effects, this Roadmap identifi es 

GEC and MagCon as the next two STP missions. GEC will measure the vitally important 

yet poorly observed region just below stable 

satellite orbits to resolve issues of ion-neutral 

support of data, computing, and community 

infrastructure ensures that progress will continue to be made. Each of these program elements and the mission strategy for each line is 

described below. We fi rst describe briefl y the 

mission strategy for each line. 

Solar Terrestrial Probes

The Solar Terrestrial Probe investigations focus on specifi c scientifi c areas required to advance our fundamental understanding of the 

Sun – Solar System connection. Successive 

missions target the ‘weakest links’ in the chain 

of understanding. STP missions are strategically defi ned and investigations are competitively selected.

STP is one of two funded strategic lines for 

the Heliophysics Program. Strategic mission 

lines afford the space physics community the 

opportunity to plan specifi c missions to address one or more of the research focus areas 

and thus make signifi cant progress in elucidating the fundamental processes of the coupled 

Sun-Earth system. In addition, such capable 

spacecraft missions often result in unexpected 

new discoveries.

The future and existing mission priority has 

been re-evaluated in light of the new priorities 

The fi gure shows the STP missions identifi ed for fl ight through 2035 using current budget projections. 

The fi gure shows the mission identifi ed for fl ight through 2035 in our optimized scenario. The improved 

synergy of STP missions is apparent. Boxes represent anticipated Heliophysics resources in units of 

medium sized missions. Mission names in blue boxes indicate that resources are committed and development is underway. Green boxes represent new missions assigned here to anticipated resources. 
62

HELIOPHYSICS

Measurements of the Solar Wind Up-Stream from Earth

Partnerships and Decision Points for Heliophysics Near L1:

In principle the operational function of solar wind monitoring upstream of Earth should be the responsibility of other U.S. government agencies. However, the L1 vantage point remains critical to Heliophysics because without knowledge of the external drivers, understanding space weather effects in geospace is problematic. Reliable prediction of geospace conditions requires accurate measurements of the incoming solar 

wind parameters. Short-term forecasts based solely on solar observations will never be detailed enough 

for terrestrial space weather needs. Fortunately, in situ solar wind conditions about an hour upstream from 

the Earth can be continuously determined by a single spacecraft. This Roadmap identifi es three possible 

L1 partnering options for long-term replacement of the continuous solar wind monitoring currently provided 

by the ACE and WIND spacecraft. Only one mission needs to be implemented by Heliophysics.

Heliostorm, in the LWS line, uses solar sails to hover twice as far upstream as an L1 mission. The mission will measure the same solar wind parameters as L1-Heliostorm, described below. This is the preferred 

option.

L1-Heliostorm provides basic measurements of the solar wind plasmas, fi elds, and energetic particles 

from the L1 position using conventional technology.

L1 Earth-Sun is a joint Earth-Sun Science partnership mission that includes an in situ solar wind package. The concept mission simultaneously conducts spectral imaging from XUV to IR of both the Earth and 

the Sun. The scope of this collaboration needs to be worked out more completely.

Decision Points and Partnerships:

If the Solar Sail Demonstration is successful, then Heliostorm would use a solar sail to provide double the 

time interval for forecasting and data assimilation into nowcasting models. The Heliophysics mission cost 

would be similar to an Explorer if NOAA and DoD partner with NASA.

If the Solar Sail Demonstration does not fl y or is not successful, then L1-Heliostorm will use conventional 

technology at L1 to provide operational solar wind data. The mission cost is small and should be very small 

to Heliophysics when shared with DoD and NOAA partners.

If L1 Earth-Sun goes forward as a science mission in partnership with Earth Science, then the total Heliophysics component should be of moderate cost; the Heliophysics cost for the solar wind component should 

be small. L1-Heliostorm would not be necessary in this case.

coupling and the processes linking the ionosphere and magnetosphere. MagCon, now 

slated for launch in 2022 in the current budget 

scenario, provides comprehensive measurements of processes in the magnetosphere with 

a fl eet of spacecraft. These and the other missions we identify are described in more detail 

in the next chapter.

Coupled with the rest of the program, these 

missions promise the best assault on the important problems facing Heliophysics. The 

slowed fi ve-year spacing between launches 

in the current budget scenario is not ideal, not 

only because progress is slow, but because 

synergy between missions is curtailed.

If additional funds can be made available 

to restore the planned 2.5 year cadence of 

STP missions the MMS, GEC, and MagCon 

missions should be fl own more quickly. They 

should be followed by Doppler & SEPM, two 

smaller missions candidates that could be 

combined to obtain measurements for understanding the initiation (DOPPLER) and the coronal evolution (SEPM) of fl ares, current sheets, 

and CME shocks that produce solar energetic 

particles. These two missions particularly benefi t from overlap with the inner heliospheric 

and solar missions planned in the LWS line. 

Next, AAMP focuses on particle acceleration 

too, but in the auroral region around Earth. Two 

more small missions, HIGO and ITM Waves, 

complete phase 2 of our plan in this optimized 

scenario. A revamped HIGO complements the 

IBEX Explorer recently selected to explore the 

outer boundary of the heliosphere; HIGO will 

measure the components of the interstellar 

medium that survive into the sub-Jovian solar system. ITM Waves concentrates on the 

wave processes fundamental to the coupling 

between distinct altitude regions and on the 

overall dynamics of the Earth’s atmosphere.

Phase 3 STP missions will measure reconnection near the Sun and observe lower latitude disturbances in the ionosphere-thermosphere-mesosphere; a stellar imager (likely a 

fl agship mission) will resolve activity on other 

stars to enable us to complete our objectives. 

Even later, more ambitious missions to explore 

the interactions of external drivers with other 

worlds in the solar system, specifi cally Titan, 
63

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

 Living With a Star

The Living With a Star program emphasizes 

the science necessary to understand those 

aspects of the space environment that affect 

life and society. The ultimate goal is to provide 

a predictive capability for the space weather 

that has important consequences. LWS missions have been formulated to answer specifi c 

science questions needed to understand the 

linkages among the interconnected systems 

that impact us. LWS investigations build on 

the fundamental knowledge gained by the STP 

missions and very directly address the needs 

of the Vision for Space Exploration and Objectives H and J of this Roadmap. Signifi cant 

planning has already informed the crafting of a 

coordinated LWS program that includes strategic missions, targeted research and technology 

development, a series of space environment 

test bed fl ight opportunities, and partnerships 

with other agencies and nations. Partnerships 

are crucial to LWS because the vast number 

of complex physical connections between and 

within the Sun-Earth system cannot be addressed by a few missions. 

LWS Targeted Research and Technology 

Program (TR&T) uniquely satisfi es two critical 

LWS needs. First, it tackles the major LWS science problems that cross the usual boundaries between scientifi c disciplines and between 

research techniques. Second, TR&T develops 

the specifi c, comprehensive models required 

to understand the LWS system, in particular 

those that can serve as prototypes for operational forecasting and nowcasting.

To achieve the fi rst, some resources are set 

aside to support new research in a few key 

areas that are recommended each year by a 

TR&T steering committee. The LWS program 

announces the targeted topics and funds science coordinators to help the competitively selected PI teams work together. This innovative 

approach assures that the best peer-reviewed 

investigators can combine their individual expertise to address the broad system science 

required to achieve specifi c LWS goals.

To meet the second need, LWS invites proposals to develop a particular set of strategic 

capabilities or technologies, also recommendVenus, and Io, could be accomplished in partnership with others to address questions of 

habitability and atmospheric evolution. Larger 

telescopes to remotely probe the solar transition region would complete our understanding 

of how energy propagates from the Sun outward and remote sensing of other planetary 

environments would close the path at the receiving end.

The Recommended LWS mission set assuming the current budget level

This fi gure shows the missions identifi ed for fl ight in the LWS program through 2035 in our optimized scenario.
64

HELIOPHYSICS

ed annually by the TR&T steering committee. The strategic capability tools are made 

available (e.g. at the Community Coordinated 

Modeling Center, CCMC) for use by the scientifi c community and for evaluation for potential 

transition to operations.

Special care must be exercised in selecting 

the targets for the TR&T program and in determining the fraction of TR&T support set aside 

for these specifi c tasks. Continued commitment to selecting the most compelling science 

investigations addressing the full spectrum of 

LWS goals serves to keep the program vital, 

relevant, and responsive.

TR&T also supports post-doctoral fellowships and summer schools intended to build 

the cross-disciplinary science community 

necessary for addressing LWS systems science. Even though the fi rst LWS launch still 

lies several years in the future, TR&T has from 

its inception delivered new capabilities that advance the goals of the program and provide a 

sound basis for planning and refi ning the science requirements of investigations on future 

missions and using the Heliophysics Great Observatory. TR&T will be indispensable for integrating the science across investigations after 

they are launched. TR&T is an essential core 

component of LWS, equivalent in importance 

to the missions.

Two LWS missions are currently in development: the Solar Dynamics Observatory (SDO) 

and the Radiation Belt Storm Probes (RBSP). 

The fi rst LWS mission, SDO, is expected to 

launch in 2008 to understand the mechanisms 

of solar variability by measuring the solar interior, atmosphere, and EUV spectral irradiance 

for at least fi ve years. Two geospace storm 

probe missions complement SDO to measure 

the terrestrial environment; all three should 

fl y simultaneously. The fi rst geospace storm 

probe, RBSP, is planned for a 2011 launch; it 

will quantify the source, loss, and transport 

processes that generate Earth’s radiation belts 

and cause them to decay. 

Our Roadmap concurs with earlier recommendations that the next two LWS missions 

should 1) complete the geospace storm probes 

by investigating ionospheric disturbances with 

the Ionosphere-Thermosphere Storm Probes 

(ITSP) and 2) explore radial evolution of solar wind structures with the Inner Heliosphere 

Sentinels mission. The priority of the ITSP mission is driven by the very practical need to aid 

communications and navigation; ITSP will observe the complex interplay of plasma - neutral processes that frequently produce both 

The diagrams suggest decision points for future missions based on technology or science criteria.
65

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

rameters as L1-Heliostorm. Heliostorm is the 

preferred option. Measurement of incoming 

solar wind parameters is crucial to many other 

investigations, so depending on Heliostorm, 

the status of the Earth Science L1-Earth-Sun 

mission, the lifetime of existing assets, and 

partnerships with other agencies, we have reserved some small amount of resources for L1 

observations.

Subsequent Phase 2 mission selection in 

the LWS program depends on future developments in the program. Priorities will shift based 

on progress of the Exploration Initiative and 

what we learn from spacecraft launched in the 

next ten years. Our baseline program shows a 

choice preceding the 2022 launch of either Solar Weather Buoys (SWB) or a pair of smaller 

missions, SECEP and GEMINI. The SWB mission provides for about a dozen in situ observing platforms circling the Sun near 1 AU to fully 

understand how the solar wind and hazardous 

disturbances propagate outward from the Sun. 

SWB could become part of the early warning system needed to support safe and productive journeys to Mars and beyond. SECEP 

(Sun Earth Coupling by Energetic Particles) 

will explore the destruction of ozone by solar 

energetic particles; SECEP will measure the 

precipitating energetic particle infl ux as well 

as the descending odd nitrogen and odd hydrogen compounds and ozone densities. The 

Geospace Magnetosphere-Ionosphere Neutral 

Imagers (GEMINI) will provide the fi rst 3-D observations of the global geospace dynamics in 

response to external solar drivers and internal 

coupling. The decision will be based on what is 

learned from STEREO, SDO, and the IH Sentinels missions on the one hand and MMS, 

RBSP, ITSP, and GEC on the other.

 Later Phase 3 choices in the LWS program 

unexpectedly large electron density plumes 

and the subsequent formation of small-scale 

ionospheric irregularities. ITSP includes a 

separate imaging instrument. The Exploration 

Initiative raises the priority of the IH Sentinels 

mission because hazardous space weather 

near Earth and in the inner heliosphere, solar 

energetic particles in particular, cannot be understood without it. In our “current resources” scenario for LWS, these two missions are 

launched within a year of each other in 2015 

and 2016. Our optimized scenario moves the 

ITSP and IH Sentinels missions ahead three 

years to provide synergy with RBSP and SDO 

and to provide earlier information for the design of systems for the return to the Moon later 

in the decade. Launching in 2012, near solar 

maximum, could also triple the number of solar 

energetic particle events (from ~10 to ~30) that 

would be available for study. We also identify an important partnership opportunity with 

ESA’s Solar Orbiter mission that complements 

the IH Sentinels in situ measurements and will 

provide solar observations from a different 

vantage point.

Subsequent LWS missions in Phase 2 address understanding energetic particle production near the Sun with the Solar Energetic 

Particle Mission (SEPM) and crucial measurements of the solar wind and energetic particle 

inputs to geospace with Heliostorm or an L1 

Heliostorm Mission. These mission candidates 

can be smaller in cost than typical strategic 

missions. The choice between Heliostorm and 

an L1 mission is complex (see box on page 60 

and top fi gure on page 62). Heliostorm would 

use solar sails to hover twice as far upstream 

of the L1 point in the solar wind for advanced 

warning of geospace disturbances. The mission will measure the same solar wind pa-
66

HELIOPHYSICS

would select among high-latitude solar observations necessary to understand the solar 

cycle and interior, two or three solar imagers 

stationed far from Earth to provide global coverage, a constellation of spacecraft to understand the inner magnetosphere, and exploration of the day-side boundary layer where 

energy from the solar wind crosses the magnetopause. The prioritization of these missions 

depends on results from earlier investigations.

In our optimized scenario the ordering 

changes slightly as shown in the accompanying chart. The SEPM mission has moved to 

the STP timeline to improve its overlap with the 

IH Sentinels and Solar Orbiter.

 The Explorer Program

The Explorer program is an indispensable element of the strategic Roadmap plan. Explorer 

missions fi ll important gaps in the prescribed 

program. These investigations target very focused science topics that augment, replace, or 

redirect strategic line missions. Highly competitive selection assures that the best strategic science of the day will be accomplished. 

Missions currently in development, AIM, 

THEMIS, and IBEX, address important targeted 

outcomes. AIM (Aeronomy of Ice in the Mesosphere) will explain polar mesospheric clouds 

formation and variability as well their relationship to global change in the upper atmosphere 

and the response of the mesosphere to solar 

energy deposition. THEMIS (Time History of 

Events and Macroscale Interactions during 

Substorms) addresses the spatial and temporal development of magnetospheric substorms 

– one of the fundamental modes of the magnetosphere. IBEX, the Interstellar Boundary 

Explorer, will image the entire 3D confi guration 

of the boundary region of our heliosphere, the 

vast (~100 AU thick) region where the solar 

wind decelerates because of the pressure of 

the local interstellar plasma.

Because future selections are determined 

competitively in response to evolving strategic 

conditions, identifi cation of specifi c future accomplishments at this time is impossible; however, numerous candidate missions have been 

identifi ed (see the Quad charts in Appendix D 

and the Heliophysics Roadmap web site for examples). The Explorer program has long been 

critical to maintaining the strength of the SunSolar System Connection (now Heliophysics) 

science program. It affords a regularly recurring opportunity to fl y exciting new missions, 

selected by peer-review for the best science 

with a relatively short response time, utilizing 

state-of-the-art instrument development. In 

addition, the program provides the opportunity 

for instrument teams to participate in missionsof-opportunity provided by other agencies 

(DoD, etc.) or international programs. These 

missions-of-opportunity allow the space physics community to obtain the data necessary for 

specifi c strategic goals at a fraction of the cost 

of a dedicated mission. SEC Explorers have 

been responsible for major scientifi c achievements that have profoundly transformed our 

understanding of the Sun-Earth system. Some 

highlights include: visualization of the global 

dynamics of the geospace system by IMAGE, 

the fi rst solar gamma ray imaging by RHESSI, 

discovery of coronal magnetic complexity by 

TRACE, discovery of trapped anomalous cosmic rays in Earth’s magnetosphere by SAMPEX, and discovery of small scale-size parallel 

electric fi elds in the auroral acceleration region 

by FAST.

Explorers demonstrate the ability of the science community to respond rapidly to decision 

points, an important element in the strategy 

put forth in the Vision for Space Exploration 

initiative. Decision points can allow us to take 

advantage of a new scientifi c discovery that 

suggests the need for a new mission, or new 

instrumentation development that provides the 

opportunity to address questions previously 

not accessible, or new technologies or analysis 

techniques that enable a less costly mission. 

Enabling rapid response of the Heliophysics 

community to such promising scientifi c opportunities ensures that science goals are met 

in the most cost- and time-effective manner. 

Results from such missions in turn may lead 

to development of new strategic missions or 

modifi cations of existing ones.

The Explorer program also plays a key role in 

developing and maintaining the scientifi c and 

engineering community needed to meet the 

objectives of the Roadmap, NASA, and the nation. Explorers provide hands-on training of in-
67

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

strumentalists, both scientists and engineers, 

thus enabling Heliophysics strategic missions, 

and directly contributing to the NASA Mission 

element “to inspire the next generation of explorers”. Managing cost-constrained missions 

such as Explorers requires specialized expertise.

Flagship and Partnership Missions. 

Urgent need for progress across a range of 

topic areas means that all of the Heliophysics 

resources cannot be applied to a single problem for an extended interval. Yet some major 

roadblocks to progress simply cannot be overcome with missions supportable in the strategic lines available to Heliophysics. Solar Probe 

in the immediate term, and Interstellar Probe 

and Stellar Imager in the more distant future 

are fl agship missions that address such problems (see inside back cover). 

Solar Probe will transform our understanding 

of the physical processes that control the heating of the solar corona, the acceleration of the 

solar wind, and the release of eruptive activity. 

Solar Probe is the fi rst fl ight into the Sun’s corona, only 3 solar radii above the solar surface. 

Accurate predictions of events that disturb 

both Earth’s human systems and affect deep 

space explorers require this understanding. 

Solar Probe can only be achieved with specifi c 

budget augmentation owing to the cost of ensuring its survival in an extreme environment. 

That said, the science and technology defi nition team currently investigating Solar Probe 

concludes that the mission is ready for a new 

start now. The decadal surveys and this roadmap identify Solar Probe as the highest priority 

fl agship mission requiring an augmentation in 

funding.

Interstellar Probe will be the fi rst mission to 

leave our heliosphere and directly sample and 

analyze the interstellar medium. It requires an 

advanced in-space propulsion system, such 

as a solar sail or nuclear electric propulsion, 

to reach the upstream interstellar medium at 

a distance of 200 AU within 15-20 years. The 

mission will be the fi rst specifi cally designed 

to directly measure the characteristics of the 

local interstellar medium, including dust, plasma, neutral gas, energetic particles, and electromagnetic fi elds. On its way, it will provide 

only the second opportunity after Voyager to 

directly observe the region of interaction between the solar wind and the interstellar medium, from the termination shock to the heliopause and beyond.

Stellar Imager (SI) is a challenging mission 

that will obtain the fi rst direct resolved (1000 

pixel) images of surface magnetic structures 

on stars like the Sun. The SI will develop and 

test a predictive dynamo model for the Sun 

and Sun-like stars using asteroseismology and 

by observing the patterns in surface magnetic fi elds throughout activity cycles on a large 

sample of Sun-like stars.

Partnerships provide another method to increase scientifi c return. Several missions have 

been identifi ed in our plan that rely on partnerExplorer missions are an indispensable element of the Heliophysics strategy. Flagship missions overcome 

roadblocks to scientifi c progress but require additional funding because of their larger cost. Partnership 

missions greatly strengthen the Heliophysics Program.
68

HELIOPHYSICS

The Heliophysics Great Observatory – Evolving to Meet the Needs of the Vision for Exploration

The very large “Halloween Solar Superstorms” described on page 6 demonstrates 

the unique and powerful capability of the Heliophysics Great Observatory to view this system of systems. The effects of the solar storms 

were observed simultaneously from the Sun, to 

the Earth, to Mars, and beyond to the edge of 

the solar system. It would not have been possible to link the consequences of these superstorms at Earth and Mars to the solar drivers 

that produced them without this collection of 

satellites and the human and computational 

resources to interpret the observations. The 

power of the Great Observatory comes from 

the combination of multiple operational assets, 

ships with other parts of NASA, as well as other U.S. government and international agencies. 

Within NASA the solar sails demonstration 

project will lay the ground work for Heliostorm, 

Solar Polar Imager, and Interstellar Probe. The 

Jupiter Polar Orbiter (JUNO) planned by the 

solar system exploration division has direct 

relevance to understanding planetary magnetospheres. Pluto-Kuiper will provide another 

opportunity to explore the outer heliosphere. 

Multiple opportunities for partnership have 

been identifi ed as part of the International Living With a Star (ILWS) program. Partnership 

with ESA on Solar Orbiter should be formalized 

in the very near term as a way to optimize and 

enhance the IH Sentinels, SEPM, and SHIELDS 

investigations. 

Enabling information about the aeronomy 

and dynamics of the Mars atmosphere is required for aerocapture, entry, descent, and 

landing. The Mars Scout program provides an 

opportunity for a collaborative mission such as 

ADAM. Future missions to refi ne our knowledge of the interaction of the Martian environment with the Sun will also be collaborative. 

The SECEP mission, designed to understand 

ozone production, is a prime candidate for collaboration with our Earth Science colleagues. 

The L1-Earth-Sun mission to understand the 

Earth’s radiation budget is another potential 

partnership with Earth Science.

timely and convenient data access, large-scale 

models, and associated data analysis. Many 

of the spacecraft are Heliophysics missions, 

but additional “observation posts” are provided by spacecraft supported by other programs such as Mars Global Surveyor (MGS), 

Cassini and the Hubble Space Telescope. For 

example, from MGS, we learned that the fl uxes 

of solar energetic particle radiation caused by 

the superstorms were quite different at Mars 

and Earth. Our Great Observatory will need 

to evolve and expand to fully understand why 

space weather effects vary so much at different locations in our solar system.

The Heliophysics Great Observatory is vital 

to our quest to understand the fundamental 

physical processes at work throughout the 

complex, coupled system that is the Sun-Solar 

System connection. For example, magnetic 

reconnection between the interplanetary and 

terrestrial magnetic fi elds is the critical physical 

process determining the size of a geomagnetic 

storm. Our strategic mission Magnetosphere 

Multiscale (MMS), currently in development, is 

being deployed to observe the physics at work 

within the small-scale diffusion region that ultimately regulates the effectiveness of solar effects on the Earth system. This single mission 

will transform our understanding of this universal plasma process. However, by utilizing 

existing missions in fl ight at the time of MMS, 

we have the opportunity to greatly increase our 

understanding of the impacts of this process 

by connecting the in situ MMS data near the 

small dayside reconnection site to upstream 

solar wind measurements and to satellitebased images of corresponding ionospheric 

airglow emissions. The resultant increase in 

knowledge improves our capability to predict 

the space environment that human and robotic explorers will experience and provides the 

foundation for future operational systems.

The Heliophysics Great Observatory will 

continue to evolve as new spacecraft join and 

older ones retire or change their operating 

modes. Missions both in their prime phase and 

in extended phases (supported by the Heliophysics MO&DA program) provide the variety 

of observation posts needed to study Sun-Solar System connections, as demonstrated by 

the 2003 Halloween Storms. A great strength 
69

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

Low Cost Access to Space

The Low Cost Access to Space (LCAS) program, whose key elements are the sounding 

rocket and balloon programs, is an essential 

component of NASA’s space physics research 

program. LCAS investigations make cuttingedge science discoveries using state-of-the-art 

instruments developed in a rapid turn-around 

environment. Of course the capabilities of the 

LCAS program must continue to evolve and 

improve so investigators can continue to do 

forefront research. Like Explorer missions, 

LCAS investigations fi ll important gaps in the 

prescribed program, augmenting strategic 

line missions. These investigations, selected 

for the best science, serve two additional purposes that cannot be adequately addressed 

in other fl ight programs: the training of experimental space physicists and engineers and the 

development and fl ight verifi cation of new instrumentation and methods.

Three examples illustrate the strategic relevance of the LCAS rocket program. One 

current investigation will use two rockets to simultaneously probe different altitude ranges in 

the polar cusp, the high-latitude region where 

Earth’s magnetic fi eld maps most directly to 

of this fl eet is that it is regularly evaluated and 

reviewed to maximize the return on the agency 

investments. This Senior Review process determines which spacecraft are most necessary 

to meet the needs of the Heliophysics program as defi ned by the community-developed 

Strategy Roadmap. The criteria for continuation include relevance to the goals of the Heliophysics Division; impact of scientifi c results 

as evidenced by citations, press releases, etc.; 

spacecraft and instrument health; productivity 

and vitality of the science team (e.g., publishable research, training of younger scientists, 

education and public outreach); promise of 

future impact and productivity (due to uniqueness of orbit and location, solar cycle phase, 

etc.); and broad accessibility and usability of 

the data. The Heliophysics Guest Investigator 

(GI) program is a critical component of the Heliophysics Great Observatory. The GI program 

enables the broadest community of Heliophysics researchers in universities and institutions 

across the country to use Great Observatory 

data in innovative scientifi c investigations pursuing the goals of this roadmap. The focus of 

competitively selected research funded by the 

program continuously evolves to ensure that 

the most important current questions are addressed.

New missions will be selected for inclusion in 

the Heliophysics Great Observatory on the basis of their demonstrated ability to satisfy the 

same criteria discussed above for successful 

operating missions. The most important of 

these, from the perspective of strategic planning, is relevance to NASA scientifi c goals. To 

meet the needs of the Vision for Space Exploration as articulated in this roadmap, will necessarily require new missions in order to characterize, understand and predict the dynamic 

environmental conditions in space. At the same 

time, some existing missions are demonstrably vital and irreplaceable and will need to be 

maintained in order to meet the agency objectives.

A Terrier-Black Brant IX rocket lifts off from Poker 

Flat Research Range near Fairbanks on its way 

into an aurora to study high-altitude plasma waves. 

Photo courtesy of Chuck Johnson, UAF Geophysical Institute.
70

HELIOPHYSICS

the solar wind. These multipoint observations 

of ions accelerated in the cusp can only be 

provided by sounding rockets and will make 

a signifi cant contribution to investigation F3.3. 

Recent rocket experiments in the South Pacifi c 

are revealing the origin of equatorial plasma 

turbulence. In this case the ability of rocket 

experiments to measure multiple vertical profi les of electric fi elds and electron density in 

the ionosphere during selected events contributes to investigation F2.4. The understanding of auroral physics gained during another, 

earlier series of rocket fl ights demonstrates the 

three-pronged role the program plays in science discovery, instrument development, and 

science training. New, higher-altitude rockets 

made evident the crucial role of microphysics 

and the need for high time-resolution measurements to elucidate the acceleration processes. 

The “top-hat” plasma detectors developed 

for these rockets are now common on space 

plasma satellite missions. The PI and graduate students went on to develop a successful 

Explorer mission as PI and instrument leads.

The other key component of LCAS is solar 

physics balloon missions, which have an outstanding record of scientifi c discoveries. For 

example, the LASCO coronagraph on board 

the SOHO spacecraft enabled systematic 

studies and arrival time predictions of coronal 

mass ejections aimed at Earth. The solar telescopes on the RHESSI Explorer mission used 

hard X-ray imaging spectroscopy, high-resolution nuclear gamma-ray line spectroscopy, 

and gamma-ray line fl are imaging to observe 

the surprising energy release process in solar 

fl ares in greater detail than ever before. These 

achievements trace their heritage to balloonborne instruments fl own in the continental U.S. 

and in Antarctica.

An essential ingredient of the Vision for Exploration is a source of well-trained engineers 

and scientists who understand the demands 

of building and delivering spacefl ight systems 

and hardware. The LCAS program provides 

important hands-on training for these human 

resources. The program involves numerous 

undergraduate and graduate students from 

diverse institutions. Graduate students can 

participate in the entire life cycle of a scientifi c 

space mission, from design and construction, 

to fl ight and data analysis; this is something 

no other fl ight program can do. The rocket 

program alone has resulted in more than 350 

Ph.D.s. In addition, a rocket or balloon experiment offers the chance for younger scientists 

to gain the project management skills necessary for more complex missions.

The combination of unique science, advanced instrument development, and training 

makes LCAS a critical path item for achieving 

NASA’s national space science goals.

Scientifi c Research and Analysis

Scientifi c research and analysis are at the 

heart of Heliophysics Division activity. The 

bulk of the discussion in this chapter relates 

to missions and their sequencing, because 

that aspect of the program is most amenable 

to long-range planning. Note, however, that 

the primary purpose of the Roadmap is to lay 

out a route to achieve the three science and 

exploration objectives detailed in the previous 

chapter. Many of the indispensable stepping 

stones along that path are supplied by the 

research and analysis programs that include 

Supporting Research and Technology (SR&T) 

and the Heliophysics Theory Program, along 

with three programs discussed previously: the 

Guest Investigator Program, LCAS, and the 

LWS TR&T.

SR&T comprises an ever-evolving suite of individual PI-proposed investigations that cover 

the complete range of science disciplines and 

techniques essential to achieve the Heliophysics Division objectives. SR&T enables exploration of innovative concepts in suffi cient depth 

to determine whether they have real potential, 

and because of this, the diversity of the program is one of its critical components. The 

Theory Program supports larger PI-proposed 

team efforts that require a critical mass of expertise in order to make signifi cant progress 

in understanding complex physical processes 

with broad importance, such as magnetic reconnection or particle acceleration. The SR&T 

and Theory programs provide not only the 

foundation on which the rest of the Heliophysics Division research enterprise is built, but 

much of the superstructure into which the individual mission efforts are integrated. These 
71

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

responsive programs develop the pioneering 

theories, techniques, and technologies that result in missions and they also capitalize on the 

new information from the missions to advance 

our understanding across the whole spectrum 

of Heliophysics.

SR&T, including the instrument and technology development components, and the Theory 

Program make vital contributions throughout 

the mission development cycle. The process 

begins with a clear defi nition of an important 

and attainable science and exploration target 

and proceeds through mission development, 

fl ight, and data analysis. In the end, a new cycle begins in which either new or newly refi ned 

questions and/or techniques are employed in 

follow-on missions. Being able to move from 

a promising science goal to a practical mission 

defi nition requires the availability of the theories, modeling, data analysis techniques, and 

instrumentation that are developed in these research and analysis programs. The approaches that are suggested on the basis of this 

groundwork are then tested via SR&T supported laboratory and/or suborbital work. Once a 

mission has actually fl own, its productivity can 

be multiplied through SR&T investigations; for 

instance, laboratory measurements may greatly enhance the quality of the information that 

can be recovered from spacecraft data or unexpected results can be explored. At the same 

time, the program supports the development 

of the new theory, data analysis, modeling, 

observing techniques, technology, and instrumentation that will be needed to address the 

next generation of questions. 

Critical contributions of these programs can 

be seen, for example, in the fi rst LWS mission, 

SDO. A primary science thrust of this mission 

is understanding the solar interior using helioseismology. Another is understanding the dynamic magnetic structure of the solar corona. 

Many of the techniques and models crucial to 

these two areas came to fruition in the SR&T 

and Theory programs. SDO also relies on technology, such as normal-incidence, multi-layer 

XUV imaging, and laboratory measurements 

that were enabled by the SR&T program. An 

upcoming STP mission provides another example. MMS will overcome obstacles to our 

understanding of magnetic reconnection, especially in the collisionless regimes found in the 

heliosphere and magnetosphere. Many of the 

current theories and models for collisionless 

reconnection have been developed through 

the Theory Program.
72

HELIOPHYSICS

Achieving NASA’s objectives requires a 

strong scientifi c and technical community to 

envision, develop, and deploy space missions, 

and to apply results from these missions for the 

benefi t of society. Such a community currently 

exists within the United States. It is a world 

leader in space physics research and exhibits 

a diverse spectrum of sizes and specialties, 

based at universities, government facilities, 

and industrial labs.

Research Infrastructure

The continued health of our research community, and thereby the ability to achieve NASA 

objectives, is dependent on many factors. 

These factors include a robust infrastructure of 

funding opportunities and resources to enable 

and maintain research initiatives; low-cost access to space for science, prototype development, and training; and a strong education and 

public outreach program to inspire and recruit 

new scientists and engineers.

The term infrastructure often refers to tangible assets, such as launch facilities, design 

and test facilities, or communications enabled 

by the Deep Space Network (DSN). These assets are a critical element of mission conception and execution. For example, long before 

major strategic missions are selected an extensive development program begins with fi rst 

generation ‘brass board’ instrument concepts; 

this is followed by near-Earth testing exploiting 

Low Cost Access to Space (LCAS) opportunities. More mature concepts can be tested in 

Explorer-class missions. The IMAGE and STEREO mission concepts provide two excellent, 

current examples of this process.

However, in addition to investing in hard assets and fl ight missions, NASA must invest 

heavily in intellectual infrastructures through 

its programs of research grants: Heliophysics 

Supporting Research and Technology (SR&T), 

LWS Targeted Research and Technology 

(TR&T), Heliophysics Theory Program, Applied 

Information Systems Research (AISR), Guest 

Investigator (GI), Virtual Observatories (VXO), 

etc. 

NASA must also invest in analysis infrastructures that support computing and data analysis 

efforts. This is a critical element in the symbiotic advance of scientifi c understanding through 

mission design: scientists use data from existing missions to improve theories and models, 

which then suggest measurements for the next 

mission. Large-scale numerical calculations, 

such as the temporal evolution of fundamental 

equations in three dimensions, require massive 

supercomputers. Without a cutting edge computing infrastructure such computations are 

not possible. A strong computing structure is 

also needed to support data analysis and data 

assimilation, especially for increasingly large 

and complex data and modeling structures.

Fortunately, much of this supporting infrastructure is in place, as evidenced by examples ranging from computing architectures 

such as the Columbia supercomputing project, 

the Community Coordinated Modeling Center 

(CCMC), the Virtual Observatory efforts, and 

NASA’s Applied Information Systems Research 

Program, to strong EPO efforts and innovative 

programs such as NASA’s Summer Faculty 

Fellowship program.

Nonetheless, our research community faces 

signifi cant challenges in the immediate future, 

challenges that directly affect our ability to meet 

NASA’s goals and support national objectives. 

The most signifi cant challenges are those of 

training new researchers while maintaining the 

corporate memory of an experienced work 

force. NASA and its supporting contractors 

will soon have large portions of their work force 

eligible for retirement. By some estimates the 

services of as much as two-thirds of the most 

experienced scientists, technicians, and managers could be lost in the near future.

Support for a competitive number of research 

teams and investigators is of paramount importance to a healthy and robust scientifi c community. There is a real danger that the loss of 

‘critical mass’ of research teams has already 

begun to impinge on NASA’s science and exploration goals. This is especially important 

for hardware development teams that have a 

high startup investment and have diffi culty retaining technical expertise in uncertain funding 

cycles. NASA support for low-level hardware 

development is generally deemed insuffi cient 

to support enough truly innovative instrument 

development. Only the largest teams are per-
73

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

ceived as capable of competition for hardware 

development. Paradoxically, the opposite can 

be said about modeling support, in that largescale modeling efforts are not suffi ciently funded for the tasks they face. In all cases, there 

must be a balance between large and small 

research efforts, as well as between pure and 

applied science.

Training opportunities at the graduate and 

undergraduate levels provide an introduction to 

all aspects of space missions, including instrument development, mission operations, data 

analysis, and theory and modeling. These often provide the fi rst opportunities for students 

to experience the excitement of working in 

space physics and provide the primary means 

of recruiting these students into the space 

physics community. NASA programs that provide low-cost access to space such as rocket, 

balloon, and airplane missions, are especially 

useful for training in that students can contribute to mission design and operations while 

obtaining data in a timely fashion for analysis. 

This is particularly important in light of the long 

development times for complex missions that 

can exceed the normal tenure of graduate education.

Universities have traditionally provided the 

bulk of the training function, though innovative co-operative programs provide additional 

training opportunities in non-University settings. The needs for a robust training program 

are necessarily tightly linked to the health and 

number of graduate education programs and 

to the education and public outreach goals 

that attract students.

The challenges discussed above are not new. 

The community has previously considered 

these problems and voiced concerns and suggested mitigation efforts through community 

efforts such as the recent NRC Decadal Survey, 

which offered specifi c recommendations for 

education and public outreach efforts as well 

as strengthening the solar and space physics 

enterprise. These recommendations remain 

relevant and are endorsed by this Roadmap.

NASA’s SR&T, TR&T, and GI programs are 

the traditional underpinning of most research 

teams and individual investigators and have 

been repeatedly recognized as such in community strategy documents. The content of these 

competitively selected programs continuously 

evolves to address new questions with innovative new methods. They have provided a signifi cant contribution to the vast body of knowledge needed for direction and implementation 

of NASA’s initiatives. It is worse than foolish 

to collect expensive data and not provide adequate resources to exploit it. Unfortunately, 

recent budget pressures have forced delays 

and cut backs in some of these programs and 

the potential impact of these delays must be 

acknowledged.

NASA Heliophysics has traditionally pursued 

cooperative research and analysis efforts with 

programs funded by other agencies, such as 

NSF’s ground-based observatory structure; the 

CEDAR, GEM, and SHINE research programs; 

and the Center for Integrated Space-Weather 

Modeling (CISM), an NSF Science and Technology Center. Current and future groundbased observations, will provide understanding of certain fundamental physical processes 

that cannot be measured from space alone; 

they provide a context for the space-based 

Earth-system measurements and enable coordinated studies of events over the entire SunEarth system.

For example the MILEURA wide-fi eld array offers another vantage point by which to 

study inhomogeneities in the solar wind, the 

Advanced Technology Solar Telescope (ATST) 

and the Frequency Agile Solar Radiotelescope 

(FASR) provide coronal magnetic fi eld measurements that Heliophysics does not have 

the resources to obtain, and chains of magnetometers provide information about the global 

electromagnetic coupling between the magnetosphere and solar wind. The Advanced Modular Incoherent Scatter Radar (AMISR) is a new 

ionospheric radar that can be deployed to different locations as science priorities change. 

An ambitious new program called Distributed 

Arrays of Small Instruments (DASI) aims to deploy a comprehensive network of remote sensing instruments that will track with unprecedented spatial and temporal resolution the 

fl ow of energy through the extended terrestrial 

atmosphere.

These longstanding partnerships will con-
74

HELIOPHYSICS

tinue to strengthen our future space-based capabilities and so must continue to be nurtured 

and supported.

In summary, this Roadmap recommends that 

NASA pursue programs across a broad spectrum of size and duration and that a portion of the 

budget be reserved for smaller strategic projects that might otherwise be overlooked. NASA 

should also seek to expand current partnerships 

with industry, universities, and other agencies. 
Chapter 4.

Heliophysics: The Missions
76

HELIOPHYSICS
77

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

The next seven near-term missions (those 

with launch planned by 2015) include one partnership and a fl agship mission. All have been 

the subject of thorough science and technology defi nition team (STDT) studies. 

The 13 intermediate-term mission candidates for the following decade include two 

partnerships and several alternative choices. 

The intermediate-term missions have either 

been considered by an STDT or have undergone an intensive, objective conceptual evaluation and costing by the GSFC or JPL mission 

study teams. 

The nine future missions (those expected to 

launch after 2025) have been studied to varying degrees. 

The seven missions described in the Partnership section are the primary responsibility 

of other divisions at NASA.

Heliophysics utilizes several mission resources. Strategic fundamental science missions are executed as Solar-Terrestrial Probes 

(STP). The Living With A Star (LWS) mission 

line is also strategic, dedicated to research on 

understanding and mitigating effects of space 

weather. Flagship Missions are grand challenge missions that require separate new starts 

outside of the STP or LWS programs. Explorer 

missions are smaller than the others and present opportunities for open competition to address strategic scientifi c questions that are 

relevant and timely. MOO’s, missions of opportunity, are inexpensive components fl own 

as part of another mission. Partnership missions receive external funding, either from other parts of NASA, other U.S. agencies, or other 

national entities. The two-page table indicates 

how missions are related to the Objectives, Research Focus Areas, and investigations developed in Chapter 2. Missions currently in development and near term Heliophysics missions 

are shown in order of approximate launch date. 

Later missions are listed alphabetically.

Heliophysics: The Missions

Chapter 4

Previous sections of the Roadmap have described the science and exploration objectives 

of the Heliophysics division, identifi ed targeted 

outcomes for the next 30 years, listed investigations and mission candidates that can provide the necessary data, and recommended 

two alternative program implementation strategies based on an optimized and the current 

budget expectations. This chapter gives more 

information about the specifi c missions and 

how they fi t into the program.

Numerous mission options were considered 

by the committee based on prior knowledge, 

community input, and 12 new mission studies commissioned by the Roadmap team. The 

missions described below are those specifi -

cally recommended in the two alternative program strategies. Not included are many exciting Explorer candidates and missions that 

cannot be accomplished in the time period we 

considered, even with the optimistic resource 

scenario. In the past Explorers have replaced 

some strategic missions. However, the number of missions may still seem large because of 

the unique challenges presented by Heliophysics system science; the evolving Heliophysics 

Great Observatory requires distributed multipoint measurements. Other factors are the 30-

year time span, the relatively modest cost of 

many missions, particularly partnerships, and 

the number of mission alternatives suggested 

in the Heliophysics strategy.

The following brief descriptions answer three 

key questions:

• What is the main purpose of the mission?

• Why does the Heliophysics strategy require 

the mission?

• When should the mission be implemented?

Further details about these and other Heliophysics mission candidates can be found in 

the Quad Charts in Appendix D of this report.

Candidate Mission Reference List

The fi rst seven missions are currently under 

development, including four Explorers. 
78

HELIOPHYSICS
79

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 
80

HELIOPHYSICS

Aeronomy of Ice in the Mesosphere (AIM)

The primary goal of the AIM mission is to resolve why Polar Mesospheric Clouds (PMCs) 

form and why they vary. In addition, AIM will 

determine the mesospheric response to solar 

energy deposition and coupling among atmospheric regions. 

AIM will examine the relative contributions 

of solar and anthropogenic effects that cause 

change in the upper atmosphere and it will examine long term change. AIM will also make 

key observations of solar energetic particle induced effects on upper atmospheric composition, in particular of odd-nitrogen compounds 

and ozone. 

AIM is a top priority in view of current heightened scientifi c and public interest in PMCs and 

the immediate need to understand how the upper atmosphere responds to variable solar energy inputs such as solar storm events. AIM is 

scheduled to launch in 2006.

Coupled Ion-Neutral Dynamics Investigation (CINDI)

CINDI, a NASA Explorer Mission of Opportunity will fl y on the Communication/Navigation 

Outage Forecast System (C/NOFS) satellite 

that is funded by the US Air Force. The CINDI 

experiment will measure the electrodynamics 

of the low latitude ionosphere resulting from 

ion-neutral interactions. The ion and neutral 

motions are key variables in the triggering of 

equatorial spread-F (ESF) and scintillation, 

which are space weather events that disrupt 

radio signal propagation over a wide range 

of frequencies. CINDI will provide the fi rst simultaneous high-resolution measurements of 

these parameters, and may lead to the development of a predictive capability for ESF and 

related irregularities.

CINDI has two separate instruments that 

measure the three dimensional ion and neutral 

thermal gas fl ows in the low latitude ionospheric F region. The Neutral Wind Meter (NWM) 

and the Ion Velocity Meter (IVM) make continuous measurements of the neutral and ion motions along and perpendicular to the satellite’s 

velocity vector. The spatial resolution of the 

CINDI instruments is on the order of one kilometer, and the precision is +/- 10 m/s for the 

neutral drifts, and +/- 5 m/s for the ion drifts. 

An important strength is that the measurements are equally sensitive in sunlit and dark 

conditions. This will allow accurate measurements of neutral winds and ion drifts near the 

sunset terminator, where the magnitude of the 

vertical plasma drift creates the conditions that 

help to initiate ESF and scintillation events.

The CINDI mission supports a number of Objective H RFAs, and has strong ties to space 

weather programs funded by NASA, the DoD, 

and the NSF. For example, diagnostic measurements from the CINDI mission will substantially augment the science return from 

ground-based observatories such as the Jicamarca Radio Observatory (JRO) in Peru, and 

the growing global network of GPS receivers. 

In addition, the polar orbiting sun-synchronous 

DMSP satellites gather ESF related data at 

high altitudes along the meridional dimension. 

The CINDI orbit is ideal for providing comparative data for lower latitudes it cuts through the 

medium in the zonal direction, thus providing 

temporal and spatial resolution that is critical 

to characterizing regions of ESF.

Time History of Events and Macroscale Interactions for Substorms (THEMIS)

THEMIS is a MIDEX Explorer mission that 

addresses the spatial and temporal development of magnetospheric substorms. The mission consists of fi ve identical spacecraft and 

an array of ground-based all-sky cameras. The 

cameras are a mission-critical element of THEMIS, providing a global context for the in situ

measurements and also detecting auroral substorm onset for mission operations decisions. 

When the spacecraft are on the day side, it will 

address the question of solar wind control of 

the magnetosphere and the coupling of energy 

across the various dayside boundaries.

THEMIS addresses the issue of onset and 

evolution of the substorm instability, an explosive yet fundamental mode of the magnetosphere. This was identifi ed by the National 

Research Council as one of fi ve main strategic 

questions in space physics.

Heliophysics Missions Currently in Development
81

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

The mission was selected in the last MIDEX 

proposal solicitation and is currently in Phase 

C/D development. The mission is scheduled 

for launch in 2006.

Solar-B

Solar-B will reveal the mechanisms of solar 

variability and study the origins of space weather and global change. NASA is a 1/3 partner 

with the Japanese space agency (JAXA) on 

this mission to investigate the detailed interactions between the Sun’s magnetic fi eld and the 

corona. High resolution observations of active 

regions on the photosphere together with an 

X-ray telescope and imaging spectrograph will 

help understand the creation and destruction 

of magnetic fi elds, variations in solar luminosity, generation of UV and X-radiation, and the 

dynamics of the solar atmosphere.

Solar B addresses most of the expected 

achievements in Phase 1 (now until 2015, page 

56): reconnection, the mechanisms of particle 

acceleration near the Sun, the origins of solar 

disturbances, understanding of the sources of 

irradiance variations, causes of the extremes in 

the local environment, and prediction of space 

weather. Many Phase 2 topics are also covered.

Solar B complements SDO, STEREO, and 

SOHO by providing high resolution imaging 

and understanding of detailed mechanisms of 

variability. The essential next step in understanding the origins of solar activity requires 

the high resolution data from Solar B, expected 

to launch in 2006 .

Solar-Terrestrial Relations Observatory 

(STEREO)

STEREO will determine the 3-D structure and 

evolution of coronal mass ejections (CMEs) from 

their eruption on the Sun through the inner heliosphere to Earth’s orbit. The mission will employ remote sensing and in situ measurements 

from two spacecraft drifting in opposite directions away from the Earth at 1 AU to triangulate 

CME-driven shocks, detect preceding shockaccelerated particles, and analyze in situ CME 

and solar ejecta signatures. As the spacecraft 

reach large separations, one spacecraft will 

observe the propagation of CMEs that will be 

directly sampled by the second spacecraft to 

provide a defi nitive determination of the relation between the white light and in situ features 

of a CME. 

This mission will also provide important information on CME-shock-accelerated particles, contributing to the characterization of 

the space environment. This mission is a high 

priority for Heliophysics science because of 

the central role of CMEs in determining space 

weather.

The Solar-Terrestrial Relations Observatory 

(STEREO) is nearly complete and ready to be 

launched in 2006.

The Two Wide-angle Imaging Neutralatom Spectrometers (TWINS)

TWINS provides stereoscopic viewing of the 

magnetosphere by imaging charge exchanged 

energetic neutral atoms (ENAs) over a broad 

energy range (~1-100 keV). Using identical instruments on two widely spaced high-altitude, 

high-inclination spacecraft, TWINS will enable 

a 3-dimensional visualization of large scale 

structures and ion dynamics within the magnetosphere. The fi rst TWINS spacecraft may 

overlap with the IMAGE mission, providing an 

early (2005-2006) opportunity for magnetospheric stereo imaging that could evolve into 

three spacecraft imaging with the launch of the 

second TWINS in 2006.

TWINS will provide a 3D view of the ring current ions in the magnetosphere. These ions 

carry much of the energy and most of the mass 

into and through the magnetosphere. Different 

from in situ observations, TWINS will provide a 

dynamic picture of the whole magnetospheric 

system with a cadence that resolves the radial 

and azimuthal ion motions. The in situ measurements provided by RBSP, MMS and ITSP, 

are truth data that can be used to further validate the necessary inversion process that will 

be applied to the TWINS data to obtain 3D ion 

fl ux distributions. These TWINS distributions 

will provide a global geospace input for space 

weather models. The 3D ion distributions will 

enable inferring the inner geospace currents 

and electric fi elds which penetrate to low altitudes and high latitudes where they couple energy into the ionosphere-thermosphere system 
82

HELIOPHYSICS

partially driving its space weather.

TWINS supports many of the objectives H 

and J, as can be seen in the discussion above. 

TWINS value is greatly enhanced if it is fl ying 

simultaneously with RBSP, ITSP and MMS. 

Solar Dynamics Observatory (SDO)

SDO will help to understand the mechanisms of solar variability by observing how the 

Sun’s magnetic fi eld is generated and structured and how this stored magnetic energy is 

released into the heliosphere and geospace. 

SDO’s goals are to understand the solar cycle, 

the transfer of energy through the solar atmosphere, and the variable radiation output of the 

Sun. SDO measures subsurface fl ows, photospheric magnetic fi elds, high-temperature solar atmospheric structures, and the extreme ultraviolet spectral irradiance that affects Earth’s 

atmosphere.

Solar magnetism drives the variability that 

causes most space weather. Helioseismology measures the internal causes of activity. 

Photospheric and coronal observations trace 

the evolution of magnetic fi eld structures and 

the origins of disturbances. The upper atmosphere is highly sensitive to solar EUV variability. SDO’s investigations are essential to many 

phase 1 and 2 achievements relevant to all 

three Heliophysics Objectives.

SDO plans to fl y near solar minimum in 2008 

to provide crucial understanding of solar activity, the solar cycle, and the inputs to geospace. 

Predictive modeling cannot improve without 

the improved data SDO will provide. SDO is 

an essential replacement for the aging SOHO 

spacecraft.

Interstellar Boundary Explorer (IBEX)

IBEX will remotely sense the global interaction between the solar wind and the interstellar medium, complementing the single-point 

direct measurements now being obtained by 

Voyager

IBEX places a spinning, Sun-pointing spacecraft in a highly elliptical equatorial orbit with 

an apogee of 35 RE so that it spends most of its 

time outside the magnetosphere. The payload 

includes tightly integrated high and low energy 

single-pixel neutral atom cameras of very high 

sensitivity needed to observe the relatively 

weak but telltale fl uxes emitted from the heliospheric boundary region. During the course of 

a year, the cameras will sweep out the entire 

sky to form a complete map of the interstellar 

boundary.

IBEX began development in May 2005 for 

launch in 2008, which may be in time for correlative operations with Voyager. Voyager 1 recently passed through the solar wind termination shock and into the heliosheath region.
83

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

Near-Term Heliophysics Missions

Radiation Belt Storm Probes (RBSP)

RBSP will focus on the variability and extremes of energetic radiation belt ions and electrons by identifying and evaluating their acceleration processes and transport mechanisms 

and identifying and characterizing their sources and losses. The RBSP instruments provide 

measurement of the energetic particle phase 

space densities plus the local AC/DC magnetic 

and electric fi elds in the inner magnetosphere 

where the intense radiation belts reside. 

RBSP consist of two small satellites in “chasing” elliptical orbits with low perigees and ~5.5 

Re apogees, and slightly different orbital periods. The different periods generate an orbital 

evolution that provides both variable radial 

separations in the same local time frame and 

local time separations at a range of constant 

radial distances to separate space-time effects 

in the radial transport and azimuthal drifts of 

the particles.

RBSP provides one link in the chain of evidence that tracks the geospace response to 

solar and interplanetary sources and variability. 

ACE, TWINS, SDO, MMS, ITSP and IH Sentinels will fi ll in many of the other links. Flying 

together, they would provide a nearly complete 

picture of geospace, its external environment 

and its responses to solar variability and evolving interplanetary plasma and fi eld structures. 

RBSP is important to objectives H and J because it provides the observations needed to 

characterize and develop models of the near 

Earth space weather. Its data will form the basis for specifi cation of the near Earth radiation 

environment and its variability on a time scale 

that meets the needs of the Exploration Vision’s 

early operations near Earth. 

RBSP data will provide a measure of the magnetospheric energy inputs to the ionosphere 

and atmosphere that are important to space 

station and crew vehicle communications, 

reentry, and atmospheric drag induced orbit 

variations. In addition, RBSP observations will 

provide new knowledge on the dynamics and 

extremes of the radiation belts that are important to all technological systems that fl y in and 

through geospace. This includes many platforms that are important to life and society as 

we rely ever more on space platforms to link us 

together through communications, to provide 

Earth resource data and to provide entertainment streams. It is also very important that we 

understand the space weather in geospace as 

we resume human exploration because it can 

impact the many US space assets that play a 

role in our national security and support human 

exploration.

Magnetospheric Multi-Scale (MMS)

MMS is the fi rst mission designed from the 

bottom up to separate spatial variations from 

temporal changes at the fi ne scales needed to 

understand the reconnection diffusion region. 

MMS will determine the fundamental physical 

properties of magnetic reconnection. 

MMS is a four spacecraft mission designed 

to study magnetic reconnection, charged 

particle acceleration, and turbulence (crossscale coupling) in key boundary regions of the 

Earth’s magnetosphere. The primary goal of the 

mission is to use high time resolution, in situ

plasma and fi elds measurements to determine 

the micro-scale processes in the exceedingly 

small (perhaps <100 km thick) diffusion region, 

where the electrons in a plasma become decoupled from the magnetic fi eld, and the fi eld 

reconnects. The close spacecraft spacing will 

also enable exploration of the cross-scale coupling of plasma turbulence in the Earth’s magnetosheath, at the magnetopause, and in the 

magnetotail. Finally, charged particle acceleration processes associated with magnetic 

reconnection, turbulence, and electric fi elds in 

the outer magnetosphere will be determined 

using direct measurement of the plasma and 

waves that cause the acceleration. MMS will 

resolve rapidly moving narrow structures, to 

yield a full understanding of the factors controlling the rate of reconnection. This will enable a 

predictive science of space weather, which in 

turn will allow us to understand energetic processes throughout the solar system.

MMS has recently entered development and 

its results will be needed as soon as possible 

as a basis for the predictive models of space 
84

HELIOPHYSICS

weather needed to undertake heliospheric 

weather prediction in support of Exploration. 

Magnetic reconnection is a primary source 

of energy release and particle acceleration in 

plasmas. No mission has ever been properly 

instrumented and confi gured to measure the 

small-scale features of reconnection in space. 

Thus, we know little about this fundamental 

process that drives much of the activity on the 

Sun, near Earth, and throughout the Solar System.

Ionosphere-Thermosphere Storm Probes 

(ITSP)

The ITSP mission is designed to investigate 

and understand the dynamic changes of the 

ionosphere-thermosphere system during solar and geospace storms. In particular, the effects of ionospheric irregularities, especially at 

mid-latitudes, have important societal consequences and are not the subject of any other 

planned mission. Variations in electron density 

of the ionosphere and changes in the neutral 

composition of the thermosphere impact radio 

propagation for communications, radar, GPS, 

and increase the drag on low altitude spacecraft.

ITSP combines imaging and in-situ measurements of the I-T system with physics-based 

models to provide the fundamental understanding required to advance IT models to the 

level of predictive capability. ITSP will investigate details of ion-neutral interactions, crossscale coupling of global processes driving mesoscale and microscale variability, circulation, 

chemistry, and the role of penetration and dynamo electric fi elds on the behavior and redistribution of the ionospheric plasma.

Two LEO satellites are necessary, slightly 

separated in local time in order to determine 

how electric fi elds, thermospheric winds, and 

composition interact to redistribute energy and 

generate changes of electron density in the 

ionosphere. Daytime thermospheric composition, nighttime electron density, and the global 

state of the system will be provided by an imager that will fl y as a Mission of Opportunity.

The scientifi c questions addressed by ITSP 

have direct relevance to the Vision for Space 

Exploration. Because ITSP will characterize, 

understand, and predict the I-T processes that 

degrade augmented GPS performance and 

produce scintillation of radio signals, similar 

concerns at Mars may be addressed by applying the knowledge gained at Earth. At Mars, 

we must be able to land with precision and 

communicate with assurance. ITSP informs 

the design of systems for precision navigation 

and communication without requiring that we 

build at Mars the equivalent of the Earth’s network of ionospheric observatories.

ITSP was designed to overlap with the SDO 

and RBSP missions in the 2008-2015 timeframe. The ITSP imager will supply context for 

the RBSP by imaging precipitation boundaries and temporal behavior of magnetospheric 

populations. The optimal schedule places 

ITSP at solar maximum and in the declining 

phase of the solar cycle when the ionosphere 

is both enhanced and disturbed. This is the 

most stressing phase of the solar cycle from 

the standpoint of technical systems and the 

extreme conditions for the advanced models 

to be developed. Under current NASA funding 

guidelines, ITSP cannot be fl own until well into 

the declining phase of the solar cycle. Further, 

the SDO 5-year mission design life concludes 

in 2013 so that an extended SDO mission lifetime will be needed to provide the required 

context observations. These are compromises 

and risks that could be avoided with a modest 

acceleration of the program.

The GEC mission may launch in a similar 

timeframe providing highly desirable scientifi c 

synergies that utilize the two orbit confi gurations and measurement complements. However, because of the urgency of each of these 

missions, each should fl y as early as funding 

permits, regardless of any loss of overlap with 

each other or the other LWS missions.

Inner Heliospheric Sentinels (IH Sentinels)

The four Inner Heliospheric Sentinel spacecraft fl ying in various formations will detect 

how structures change in space and time during the transit. IH Sentinels investigations will 

discover, model, and understand the connection between solar phenomena and geospace 

disturbances.

Interactions in interplanetary space make the 
85

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

determination of the linkage between pointsampled 1 AU measurements and their solar 

sources diffi cult or impossible. IH Sentinels 

science is important to understanding which 

disturbance will be geoeffective and for developing predictive capability. The interactions relate to particle acceleration, the drivers 

of space weather and characterization of the 

extreme conditions near Earth and throughout 

the heliosphere. Most space weather evolves 

as it passes through the inner heliosphere. Understanding this infl uential region of space is 

required for safe and productive use of space. 

IH Sentinels should fl y in conjunction with SDO 

and will contribute to understanding gained by 

the two LWS Geospace Storm Probe missions. 

In an extended mission they will provide essential information about material that eventually reaches SWB or other spacecraft at 1 AU 

and beyond

Solar Probe (SP)

Solar Probe will be the fi rst fl ight into the 

Sun’s corona, only 3 solar radii above the solar 

surface. Solar Probe’s instruments measure 

plasma, magnetic fi elds and waves, energetic 

particles, and dust that it encounters. They 

also image coronal structure surrounding Solar 

Probe’s orbit and in polar structures at the coronal base. Solar Probe makes two passes into 

the corona, separated by 4.5 years, exploring 

why the corona changes its whole form over 

the solar cycle.

The corona is heated to millions of degrees 

by poorly understood processes governed by 

the Sun’s magnetic fi eld. The UV radiation from 

the hot solar atmosphere affects the chemistry 

of the atmospheres of the Earth and other planets. The boundary where the corona accelerates to become the solar wind governs the heliosphere and its interactions with the planets 

and the interstellar medium. That boundary is 

also critical to the release of solar disturbances 

that travel throughout the solar system, to the 

Earth and other planets, producing energetic 

particle events and magnetospheric storms. 

Solar Probe will transform our understanding 

of the physical processes that control the heating of the solar corona, the acceleration of the 

solar wind, and the release of eruptive activity. 

Accurate prediction of events that disturb the 

Earth’s human systems and deepspace explorers require this understanding.

One factor sets the placement of Solar Probe 

in the Roadmap: Solar Probe is the most technically challenging mission attempted. It must 

survive in the cold and intense particle radiation environment of its orbit-shaping fl yby at 

Jupiter, and function through the heat and 

high-speed dust impacts of the solar corona. 

The path to meet the technical challenges is 

now well defi ned and Solar Probe is ready 

for a mission start. Solar Probe can only be 

achieved with specifi c budget augmentation 

because the work to ensure surviving its diffi -

cult environment keeps it more costly than any 

mission line can support.

Solar Orbiter (SO)

Solar orbiter is a European Space Agency 

(ESA) mission with U.S. participation that will 

fl y as close as 45 solar radii to the Sun in order 

to study the solar atmosphere with unprecedented spatial resolution (~100 km pixel size). 

Its science goals are to characterize the properties and dynamics of the inner solar wind, to 

understand the polar magnetic fi elds using helioseismology, to identify links between activity 

on the Sun’s surface and coronal disturbances 

using co-rotating passes, and to fully characterize coronal regions from high inclination orbits. Using Venus gravity assists, the orbital inclination will shift over time, providing the fi rst 

high latitude views of the solar poles. Solar Orbiter will provide key components to NASA’s 

LWS program by understanding the causes of 

space weather and thus will answer science 

questions of Objective H. It will also provide 

data to increase our fundamental understanding of particle acceleration and the role of the 

solar dynamo in structuring the solar magnetic 

fi eld (Objective F). 

Both science areas are essential in developing a short and long term predictive capability 

for the Exploration Vision (Objective J). Solar 

Orbiter is slated to fl y in the 2015-2025 (Phase 

2) time frame which will coincide with Inner Heliospheric Sentinels to continue the system science of our Great Solar Observatory.
86

HELIOPHYSICS

Geospace Electrodynamic Connections 

(GEC)

GEC will determine the fundamental processes coupling the ionosphere and thermosphere. 

The upper atmosphere is the fi nal destination 

of the chains of fi elds, particles and energy that 

start at the Sun, transit the heliosphere, and 

are modifi ed by the magnetosphere and upper atmosphere. To transform and inform our 

understanding of this fundamental question a 

formation of 3-4 spacecraft must be sent to resolve the spatial structures and time variations, 

repeatedly and systematically, into the depths 

of the atmosphere of this transition region: 130 

to 180 km above the Earth. The spacecraft 

will have complete instrument packages that 

measure both the magnetosphere energy/momentum inputs at high latitudes and the atmosphere-ionosphere responses. 

GEC will transform our understanding of the 

chain of events from the sun to the atmosphere 

by providing for the fi rst time, comprehensive, 

collocated, simultaneous atmospheric measurements, the models with which to interpret 

them, and context setting measurements of the 

Sun, heliosphere, and magnetosphere. This 

region cannot be understood without actually 

making the in situ observations. GEC does this 

using proven technologies, such as formation 

fl ying, to unravel the spatial and temporal coupling of the transition region phenomena in a 

reconfi gurable observatory. 

GEC will transform our understanding of fundamental processes in the upper atmosphere. 

It will also enable practical applications relevant 

to Protecting our Home in Space, and the Outward Journey. Dipping the spacecraft from the 

collisionless into the collisional regime of the 

atmosphere provides an analog for aerobraking and aerocapture operations at Mars. 

Under current NASA funding guidelines, GEC 

is planned for launch in 2017, with a two -year 

prime mission lifetime. It is possible that GEC 

will overlap with the ITSP mission, with corresponding synergies that are discussed under 

the ITSP description. However, each mission 

provides unique measurements and insights, 

and neither one should be delayed for the sake 

of overlap.
87

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

Auroral Acceleration Multi-Probe (AAMP)

The Auroral Acceleration Multi-Probes 

(AAMP) mission is designed for extremely high 

time resolution in situ measurements of particle distributions and three-dimensional electric 

and magnetic fi elds within the Earth’s auroral 

acceleration region. The auroral acceleration 

region provides a unique laboratory for the 

study of acceleration processes, both because 

it reveals many of the critical processes and 

because it is readily accessible to measurement. Our basic understanding of particle acceleration in parallel electric fi elds and kinetic 

Alfven waves, as well as the structures that 

support parallel fi elds, have come from in situ

auroral observations. To make the progress required for a predictive understanding requires 

simultaneous measurements both along and 

perpendicular to magnetic fi elds. The four satellite AAMP mission is designed to provide the 

needed conjunctions through a careful orbit 

strategy. 

One of the key goals of Objective F is providing the detailed understanding of the processes 

that accelerate particles to high energies that 

will be necessary to predict fl uxes of high energy particles throughout the solar system. This 

predictive capability is the goal of RFA J.3. In 

addition, by providing a better understanding 

of energetic particles in the Earth’s space environment, AAMP is also important to Objective 

H because it will enable mitigation of impacts 

on space assets, and, by quantifying the auroral input to the ionosphere/thermosphere, it will 

improve models of lower latitude composition 

and variability of the ionosphere, which affect 

communications/navigation activities. 

The fundamental understanding of acceleration processes is critical to the NASA Heliophysics goals and, thus, the mission should 

be fl own as soon as possible. Its placement in 

the mission queue indicates the need to inform 

activities that occur in the intermediate time 

frame.

DOPPLER

DOPPLER consists of a suite of small, lightweight, moderate resolution spectral imagers 

(UV/EUV imaging spectrograph, 2 EUV imagers, and a Magnetograph) to detect, observe 

and study remotely all of the relevant signatures 

of solar activity responsible for space weather 

events and disturbances. 

DOPPLER addresses issues directly relevant to supporting the Vision for Exploration 

by enabling improved nowcasting and future 

forecasting of solar activity by identifying and 

developing new precursor signatures of CME 

initiation and onset, fl are eruption, and fl are initiated Solar Proton Events. The DOPPLER mission enables improved nowcasting and forecasting of solar activity by providing improved 

understanding of the physical processes and 

mechanisms of energy storage and release on 

the Sun. Measurements of motions and changes in nonthermal velocity distributions in the 

lower corona and chromosphere are crucial to 

understanding and separating various models 

of CME initiation and onset. Depending upon 

the specifi c physical process, Dopplergrams 

and other derived data products are likely to 

be the most reliable indicators that a specifi c 

region is about to erupt. 

The DOPPLER mission should fl y in the early 

part of Phase 2 (2015-2020), with overlap with 

SDO to identify and develop new solar activity precursor signatures necessary to protect 

astronauts during surface EVAs on the Moon 

(late Phase 2). The small, lightweight instrumentation developed by DOPPLER would then 

be available for Phase 3 missions required to 

provide nowcasting and forecasting capability 

at Mars and beyond.

Geospace Magnetospheric and Ionospheric Neutral Imager (GEMINI)

GEMINI will provide the fi rst 3-dimensional 

observations of the global Geospace dynamics 

in response to external solar drivers and internal 

coupling. Stereoscopic views of the radiation 

belt associated ring current and thermal ions of 

the plasmasphere, simultaneous images of the 

aurora in both hemispheres, and coordinated 

ground based observations are used to determine the coupling dynamics between the ionosphere, ring current, and plasmasphere and to 

Intermediate-Term Heliophysics Missions
88

HELIOPHYSICS

discover the important feedback and dissipative mechanisms between these regions. 

The power of GEMINI is that imaging this 

complex coupled system to unravel its macro-scale interactions simultaneously provides 

the global context for correct interpretation of 

in-situ observations. It is to magnetospheric 

space-weather what the Solar Terrestrial Relations Observatory (STEREO) is to the solarwind observations. The discoveries from this 

mission are applicable to understanding fundamental processes at work not only in Geospace but other magnetized planetary systems 

and thus are important to Objective F. Global 

Geospace observations are needed to provide 

the system level context for nowcasting and 

prediction of the plasma environment where 

exploration activities are occurring within 

Geospace. In addition, these results are signifi cantly augmented when coupled with inner 

heliospheric and solar disk observations. The 

conjugate auroral observations are essentially the “footprints” of the magnetosphere and 

therefore provide the magnetospheric confi guration to distances beyond the lunar orbit. For 

these reasons GEMINI is important to Objective J.

Operating GEMINI in conjunction with the 

RBSP and ITSP missions is ideal, as documented in the LWS Geospace defi nition report. However, even without mission overlap, 

the system level understanding of the coupling 

between regions in Geospace that creates, 

evolves and annihilates radiation belts and how 

that induces and impacts ionospheric variability is extremely signifi cant to operational space 

based assets that society has become so dependent on. As such, GEMINI is important to 

objective H.

Heliostorm 

Heliostorm will measure the solar wind and 

heliosphere state “upstream” of the Earth and 

Moon. Through the use of breakthrough solar 

sail technology, it would fl y 50% further from 

the Earth (farther upstream) than the current 

ACE measurement at the Earth-Sun L1. A set 

of in-situ measurements then would provide 

50% greater warning time (compared to ACE) 

of CMEs and shock-accelerated energetic particles. In conjunction with other assets outside 

the Earth’s magnetosphere, the mission would 

determine the structure of the solar wind on 

spatial and temporal scales that are relevant 

for driving magnetospheric processes.

Heliostorm safeguards our outward journey 

by providing an input that is absolutely vital 

to the prediction of space weather in cislunar 

space. Astronauts on the lunar surface will 

benefi t greatly as the enhanced warning time 

will permit reaction to actual upstream conditions measured by Heliostorm. The solar wind 

input to the Earth is required by all models 

of the Earth’s magnetosphere, and would be 

provided by Heliostorm or a conventional L1 

monitor.

Heliostorm could be fl own 5-6 years after a 

successful Solar Sail Flight Validation (Solar 

Sail Demo). Heliostorm (or a conventional L1 

monitor) must be fl own in time to replace the 

current ACE/Wind confi guration. This suggests a launch in the 2016-2020 time frame.

Heliospheric Imager and Galactic Observer (HIGO)

HIGO will establish the 3-D structure of the 

interaction region between the heliosphere 

and the local galactic environment. It will determine the nucleosynthetic status of a present-day sample of the galaxy and explore the 

implications of this knowledge for big bang 

cosmology, galactic evolution, stellar nucleosynthesis, and the birthplace of the Sun and 

solar system. HIGO will characterize the physical state of the local interstellar cloud and the 

nature of its interaction with the heliosphere, 

map the location and establish the characteristics of the extended inner source of neutrals 

in the heliosphere, and set limits on the dust 

density in the heliosphere. HIGO will search for 

molecules and the building blocks of life liberated by sublimation of small comets, asteroids 

and grains, detectable through measurement 

of pickup particles.

The spacecraft will use a Venus-Earth gravity 

assist to attain a fi nal 1 x 4 AU equatorial orbit. 

A spin-stabilized spacecraft supports imaging 

the heliopause and the solar wind termination 

shock, determination of the isotopic and elemental composition of the neutral portion of 
89

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

the interstellar gas; measurement of the fl ow 

direction, speed and temperature of interstellar 

atoms, and the composition and radial profi les 

of extended inner source pickup ions. HIGO 

also will detect time-dependent interactions of 

large-scale structures with heliospheric interfaces.

HIGO is important for understanding the fundamental interactions of plasmas and neutrals 

(F.3), the role stellar and interstellar fi elds play 

in planetary habitability (H.4), and the variability 

of galactic cosmic rays (J.1).

HIGO is an important precursor for optimizing the Interstellar Probe (ISP) fl agship mission 

and will benefi t from the knowledge gained by 

IBEX and Pluto/Kuiper. HIGO is a small mission that should be fl own during phase 2.

Ionosphere Thermosphere Mesosphere 

Waves (ITMW)

ITM Waves is designed to observe the sources and sinks of gravity waves, including modes 

of interaction between multiple wave sources, 

as well as modes of interaction with the neutral 

and ionized constituents of the atmosphere, 

and with tides and the zonal mean circulation. 

The wave processes studied by ITM Waves 

are fundamental to the coupling between distinct altitude regions, and to the overall dynamics of the Earth’s atmosphere. These processes 

play a key role in the response of the atmosphere to solar storms. Gravity waves are also 

thought to be a critical factor in preconditioning the ionosphere by contributing to the initial 

conditions necessary for plasma instabilities to 

form near the magnetic equator, and perhaps 

also at mid-latitudes. These unstable conditions can result in the formation of large-scale 

depletions in the plasma density, coupled with 

small-scale irregularity formation and severe 

radio wave disruptions. The ITM-Waves mission will thereby enable further development of 

the theory and models necessary for comprehensive understanding of the phenomena. Insight into these phenomena in geospace may 

help to mitigate issues related to aero-braking 

and aero-capture in the Martian atmosphere, 

so ITM-Waves is pertinent to exploration mission requirements.

ITM-Waves should follow GEC and ITSP as 

closely as possible in time because these two 

missions provide key information on how the 

atmosphere responds to solar energy, storms, 

and substorms. Together the three missions 

are synergistic in that they address the overall goal of understanding the Earth’s response 

to solar energy. If possible, ITM-Waves should 

overlap in time with the Mars Dynamics mission 

(ADAM) because additional synergies would be 

created by studying the responses of both atmospheres to simultaneous solar forcing.

L1-Sentinel

In situ observations from the Earth-Sun L1 

point are essential to understanding geospace 

and provide about one hour of warning of disturbances traveling toward Earth in the solar 

wind. The essential quantities are plasma, 

particles and fi elds measurements. Enhancing 

capabilities include radio sensing, composition 

and high-energy particle detection, and even 

solar observations, though these can often be 

accomplished from other vantage points. 

Without upstream information the state of 

the magnetosphere cannot be understood. 

Models of propagation in the inner heliosphere 

need a reference at 1 AU against which to test 

their models. Spatial variations in structures 

around L1 are not well understood. Data from 

L1 is needed at all times to provide adequate 

warning for many operational users in addition 

to NASA scientists.

The timing of this mission depends upon future assets launched by NASA and other agencies and the continued functioning of existing 

spacecraft. The existing Great Observatory 

provides L1 observations and some future mission must do the same. Partnerships may be 

the preferred method for satisfying the need 

for observations from L1. The possible fl ight 

of Heliostorm, an Earth Science L1 mission, 

or collaboration with the IH Sentinels or SWB 

missions may provide additional options.

Magnetospheric Constellation (MC)

MC will employ the fi rst sensor web of ~36 

spacecraft in the Earth’s magnetosphere that 

can describe the temporal and spatial structure 

of complex turbulent plasma processes. These 
90

HELIOPHYSICS

phenomena occur throughout the vast regions 

of the Earth’s magnetosphere, including much 

of cislunar space between the Earth and its 

moon, as well as the important magnetotail. In 

situ plasma, magnetic fi eld, and energetic particle observations will be used to distinguish 

between nonlinear internal dynamics of the 

magnetosphere and global responses to varying solar wind conditions. The observations 

will resolve spatial and temporal scales suffi -

cient to enable close cooperation with stateof-the-art numerical simulations capable of 

describing magnetic fl ux, mass transport, energy conversion, and dissipation. By removing 

the spatial and temporal ambiguities that limit 

single spacecraft and extending the reach of 

clustered spacecraft missions to larger scales, 

MC will be the fi rst to reveal the mesoscale 

pattern of changes within the magnetosphere. 

It will quantify the location and extent of the 

instabilities that trigger the explosive release of 

solar wind energy and mass stored in the magnetosphere, and the transport of these quantities between regions.

A distributed sensor-web array of spacecraft 

is the logical successor to the Magnetospheric 

Multi-Scale Mission (MMS), which is designed 

to penetrate the microscale physics of reconnection using four closely spaced spacecraft. 

MC will establish the fi rst true meteorological 

facility for the mesoscale study of storm development in space weather. Understanding the 

mass and energy fl ow in the magnetotail and 

throughout the rest of the magnetosphere is an 

unresolved issue of fundamental importance 

for understanding this environment. With the 

fl ight of the New Millennium ST-5 mission, all 

of the technological obstacles to this mission 

have been addressed. MC could be the next 

STP mission after GEC, which puts it in the 

Phase 2 mission queue.

Sun-Earth Coupling by Energetic Particles 

(SECEP)

SECEP seeks to understand and quantify 

the impact of solar energetic particle precipitation (EPP) on atmospheric composition. EPP 

is thought to be a signifi cant source of ozone 

destruction through production of high altitude 

odd nitrogen and odd hydrogen compounds 

which can be transported lower in altitude 

where they will catalytically destroy ozone. In 

order to understand these processes SECEP 

will measure the precipitating energetic particle infl ux as well as the descending odd nitrogen and odd hydrogen compounds and ozone 

densities. Other relevant parameters which affect these processes such as temperature and 

winds will also be observed.

SECEP is crucial to Heliophysics goals because it studies a key link between solar energy and its impact on the habitability of Earth. 

Dramatic effects of EPP on stratospheric and 

mesospheric ozone have been demonstrated 

by recent observations. The impact is greatly 

magnifi ed by the long lifetime of odd nitrogen 

compounds at stratospheric altitudes. The descent of the odd nitrogen compounds from 

the ionosphere where it is created to the mesosphere and stratosphere occurs primarily in 

the polar night where destruction by photolysis 

can not occur. Therefore SECEP provides valuable fundamental science on how atmospheric 

regions are coupled. 

Because ozone plays a key role in Earth’s 

habitability by shielding the population from 

harmful UV radiation, SECEP is a high priority 

mission. SECEP should follow GEC and ITSP 

closely in time because these two missions 

provide key information on how the atmosphere responds to solar energy and the three 

missions together are synergistic for the overall goal of understanding the Earth’s response 

to solar energy and the effect on the human 

population.

Solar Energetic Particle Mission (SEPM)

SEPM will determine how, when, and where 

solar energetic particles (SEPs) are accelerated and help determine how the solar wind 

is accelerated. A large aperture UV coronagraph-spectrometer and a large aperture visible light coronagraph-polarimeter will observe 

the corona from 1.15 to 10 solar radii. SEPM 

instrumentation will be about 100 times more 

sensitive than current coronagraphs. New diagnostics will determine velocity distributions 

for electrons and minor ions and derive magnetic fi eld strengths in coronal streamers and 

coronal mass ejections (CMEs). SEPM will 
91

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

measure critical plasma parameters in pre- and 

post-shock CME plasmas including suprathermal seed particle populations and it will characterize upstream turbulence which is believed 

to play a critical role in particle acceleration. 

When combined with an integrated theory 

and modeling program, SEPM measurements 

will be used to signifi cantly advance our fundamental understanding of energetic particle 

acceleration (Objective F). Ultimately this understanding will be used to develop a predictive capability for the fl ux, energy spectrum, 

and composition of SEPs – thus enabling the 

Exploration Vision (Objective J) and providing 

information about the solar sources of space 

weather that affect our home planet (Objective 

H). 

Ideally the remote sensing SEPM spacecraft 

should fl y in concert with a near-Sun spacecraft 

(e.g. Inner Heliospheric Sentinels or Solar Orbiter) that will detect energetic particles before 

signifi cant scattering in the interplanetary medium. SEPM should start as early as possible 

during a period of high solar activity to inform 

the development of SEP hazard prediction before human explorers return to the Moon. 

The possible combination of the SEPM and 

Doppler missions promises a powerful tool for 

understanding the physical processes of solar energetic particle acceleration and relating 

SEPs to fl ares on the disk and to coronal mass 

ejections that propagate out into interplanetary 

space.

Solar Polar Imager (SPI)

Solar Polar Imager will provide critical missing observations need to understand the solar 

cycle and the origins of solar activity. It is a 

single spacecraft mission that uses a solar sail 

to achieve a fi nal 0.48 AU circular orbit with a 

75o inclination to the ecliptic. The spacecraft 

carries a magnetograph/Doppler imager for 

high-resolution helioseismology and surface 

magnetic fi eld measurements of the polar regions, a coronagraph for polar views of the 

equatorial corona and CMEs, and in situ particles and fi elds instrumentation for solar wind 

and energetic particle observations. 

This mission is necessary to understand the 

solar dynamo because the polar orbit enables 

us to measure the convective surface, subsurface and deep interior fl ows that control the 

solar dynamo and to observe the correlation 

between the fl ows and solar magnetic fi eld activity and evolution. The rapid four-month polar 

orbit also allows us to observe the relationship 

between solar activity and solar wind structure 

and energetic particles at all latitudes, crucial 

for characterizing the near-Sun source region 

of the space environment. In addition, the polar magnetic fi eld measurements are needed to 

provide the solar surface boundary conditions 

for the global MHD models used for space 

weather prediction.

Because this mission requires a solar sail to 

achieve the near-polar orbit, it has been placed 

after the Heliostorm mission that will be the fi rst 

science mission utilizing solar sail propulsion. 

The Telemachus mission can also address the 

goal of characterizing the space environment 

at all latitudes and give some information on 

the magnetic fi elds and fl ows in the polar regions. Thus at some point, the community 

may choose between Solar Polar Imager and 

Telemachus, based in part on the maturity of 

the solar sail propulsion technology.

Solar Weather Buoys (SWB)

SWBs are ~15 small spacecraft distributed 

every ~20o in ecliptic longitude around the Sun 

at 0.9 AU, identically instrumented with plasma, magnetic fi eld, energetic particle, and hard 

x-ray detectors.

The initial function of SWBs is to answer 

defi nitively the yet unresolved basic scientifi c question: what is the spatial longitudinal 

extent and evolution of the major Solar Energetic Particle (SEP) and Coronal Mass Ejection 

events that occur during the maximum of the 

solar cycle? Their complementary function is 

to give prompt and unambiguous warning of 

the injection of biologically damaging doses 

of high-energy particle radiation for astronauts 

exposed on the surface of the Moon or in transit to the surface of Mars. 

SWBs will attack the fundamental problem 

(F.2) of bringing our understanding of the acceleration and propagation of SEPs and CMEs 

from the Sun to 1 AU up to the level of prediction. In its complementary role, it will safeguard 
92

HELIOPHYSICS

our outward journey (J.2) to the surfaces of the 

Moon and Mars.

By launching in 2022, the 5-year deployment phase will be completed in time to catch 

the rise-to-maximum phase of the solar cycle 

(2027-2030). During the remainder of the solar 

cycle (2031-2036), SWBs will paint a defi nitive 

scientifi c picture of how large SEPs and CMEs 

propagate from the inner heliosphere (being simultaneously observed by IH Sentinels, Solar 

Orbiter, and solar imagers) to 1 AU and beyond 

towards Mars - orbit at 1.4 AU. During this 

time SWB’s prompt warning capability will be 

honed and perfected so that they will function 

with high reliability at the anticipated launch 

time for the manned mission to Mars (2035).

Telemachus

Telemachus will increase our understanding 

of the changing Sun and its effects throughout 

the Solar System. It reveals through helioseismology how convection and rotation couple 

and magnetic fl ux accumulates in the polar regions. (F.4) It will uncover the mechanisms in 

the polar regions of the Sun that accelerate the 

solar wind and energetic particles and expel 

plasma and magnetic fi elds (H.1, J.2). From 

it’s high ecliptic latitude orbit, it can exploit the 

polar viewpoint to examine the distribution of 

radio and x-ray emission simultaneously from 

all solar longitudes. The mission will determine 

the physics of the strongest stream/stream 

plasma interactions and transient shocks where 

they are fi rst formed in the heliosphere. (J.3)

Telemachus shares many objectives with the 

Solar Polar Imager. Telemachus’ orbit provides 

less frequent and more distant coverage of the 

solar poles than SPI, limiting it’s coverage of 

the events of interest. However, it does not require solar sails for implementation.

Telemachus should fl y in conjunction with the 

Solar Wind Buoys and the SEPM and IH Sentinels missions for optimum effectiveness. Collaborations with either the Farside Sentinel or 

SHIELDS mission make it’s scheduling late in 

Phase 2 appropriate. Earlier fl ight would provide crucial information about the Sun’s activity cycle sooner.
93

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

Future Heliophysics Missions

Dayside Boundary Constellation (DBC)

DBC will determine the global topology of 

magnetic reconnection at the magnetopause. 

It is a network of ~30 Sun-pointing, spinning, 

small spacecraft, separated by ~1 RE, that 

skim both the dawn and dusk sides of the dayside magnetopause. The multiple spacecraft 

provide simultaneous comprehensive observations of boundary phenomena including turbulence over a wide range of latitudes and local 

times. Three spacecraft are boosted to have 

apogee outside the bow shock to provide continuous monitoring of the foreshock-preconditioned solar wind input. 

This mission addresses critical unresolved 

questions about the transfer of energy across 

the magnetopause boundary. It also will robustly measure the global magnetic fi eld topology on the Earth’s dayside magnetopause, 

something which has not been done before. 

MagCon is a precursor mission to DBC, as 

it will have a constellation of spacecraft in the 

magnetospheric equatorial plane. Therefore, 

DBC should be in the Phase 3 mission queue.

Farside Sentinel (FS)

Farside Sentinel is a solar observatory with 

a spacecraft placed at 1 AU viewing the far 

side of the Sun. It will provide new knowledge 

about the solar dynamo, solar activity, and the 

dynamic space environment in general. It contains both remote sensing and in situ instruments. Remote sensing instruments include 

a magnetograph-Doppler imager and a radio 

science package for coronal sounding. Its location about 180 degrees from Earth allows, 

in conjunction with similar observations from 

near Earth, helioseismological measurements 

of the deep interior fl ows that are thought to 

drive the dynamo. The magnetograph will provide more longitudinal coverage of the Sun 

so that the evolution of solar magnetic fi elds 

and active regions can be observed for longer 

times. A solar far-side observatory also provides an additional in situ observation post for 

the space environment. The in situ instrument 

package would be similar to that on the STEREO spacecraft. 

The Farside Sentinel provides information 

crucial for understanding fundamental processes (Objective F) and for developing the 

capability to predict the space environment. 

Farside will aid predictions of space weather 

and provide inputs for SWB, MARS, and highlatitude solar observatories. 

While it would be advantageous to have this 

(or the SHIELDS) mission earlier, it was placed 

in Phase 3 because it was considered lower 

priority.

Inner Magnetospheric Constellation (IMC)

IMC will determine the interaction among 

the radiation belts, ring current, plasmasphere, 

and outer magnetosphere. It requires multiple 

spacecraft in at least two ecliptic plane “petal” 

orbits. Large day/night and dawn/dusk asymmetries exist in the inner magnetosphere and 

complicate the global specifi cation of particles 

and fi elds. Through simultaneous measure of 

radial and longitudinal variations in the radiation belts, the temporal and spatial asymmetries will be resolved. 

The in situ measurements from these multiple positions allow the construction of comprehensive “weather maps” of the inner magnetosphere (1.5-12 Earth radii) that evolve in 

response to Sun-induced disturbances. This 

spacecraft fl eet focuses on detailed specifi cation of the orbital environment of most spacecraft and manned missions, to determine in 

detail the origin and evolution of particle populations and their interaction with the evolving electro-magnetic fi eld during magnetic 

storms.

These observations extend the Radiation Belt 

Storm Probe results by making simultaneous 

maps of the radial as well as the longitudinal 

variations in the radiation belts. It should fl y 

after RBSP, and probably after GEMINI, putting 

it into Phase 3 of the mission queue.

Interstellar Probe (ISP)

Interstellar Probe is the fi rst mission that will 

leave our heliosphere and directly sample and 

analyze the interstellar medium. It is a single 
94

HELIOPHYSICS

spacecraft that will use an advanced in-space 

propulsion system, such as a solar sail or nuclear electric propulsion, to reach the upstream 

interstellar medium at a distance of 200 AU 

within about 15-20 years. This spacecraft will 

carry the fi rst payload specifi cally designed to 

directly determine the characteristics of the local interstellar medium, including dust, plasma, 

neutral gas, energetic particles, and electromagnetic fi elds. 

On its way, it will provide only the second opportunity after Voyager to directly observe the 

thick region of interaction between the solar 

wind and the interstellar medium, from the termination shock to the heliopause and beyond. 

This region plays a central role modulating the 

galactic cosmic ray fl ux and in the creation of 

the anomalous component. Understanding 

this modulation will help increase the productive and safety of human explorers. Additional 

advanced instrumentation used en route could 

determine the nature and chemical evolution 

of organic molecules in the outer solar system 

and interstellar medium and measure the cosmic infrared background (CIRB) radiation normally hidden by the zodiacal dust.

Because this mission is enabled by advanced 

propulsion, it has been placed in Phase 3. The 

Solar Polar Imager mission would provide a 

technology demonstration of the solar sail propulsion system needed for Interstellar Probe. 

Additional resources will likely be needed for 

this mission because of its 15+ year lifetime 

coupled with the need for advanced propulsion.

Tropical ITM Coupler (ITMC)

ITMC will explore how neutral and plasma interactions distribute energy within and between 

Earth’s low-latitude mesosphere, thermosphere, ionosphere, and inner plasmasphere. 

ITMC will improve our understanding of the 

infl uence of geospace on Earth (Objective H), 

explore the fundamental interactions between 

atmospheric plasmas and neutrals across 

scales from 1 cm to 1000 km (Objective F), 

and provide a fundamental database of atmospheric dynamics (winds, gravity waves, and 

ion drifts) that can be applied to exploration of 

other planets (Objective J).

ITMC should be fl own after the GEC and ITSP 

missions and should be reconfi gured as necessary to address unanswered questions from 

those missions. In the event of limited fl ight 

opportunities, the importance of ITMC can be 

evaluated in light of the GEC and ITSP results.

Magnetic TRAnsition region Probe 

(MTRAP)

The primary objective of MTRAP is to measure the build up and release of magnetic 

energy in the solar atmosphere. MTRAP will 

measure the vector magnetic fi eld from the 

photosphere to the magnetic transition region, 

where the solar atmosphere changes from 

being plasma to magnetic fi eld dominated. 

MTRAP will also obtain simultaneous plasma 

diagnostics of the magnetic transition region 

with UV/EUV imaging spectrograph measurements. MTRAP has two orders of magnitude 

greater collecting area and one order of magnitude improvement in angular resolution over 

Solar-B and will greatly improve our ability to 

follow rapid changes in the magnetic fi eld geometry. MTRAP is centered around a very large 

solar optical telescope with a six meter aperture, providing over 100 times the collecting 

area and 10 times the angular resolution (0.05 

arcseconds) of Solar-B. 

MTRAP addresses fundamentally important 

questions and issues related understanding 

magnetic reconnection and micro-scale instabilities in the chromosphere/corona interface 

on the Sun. 

MTRAP should fl y early in Phase 3 of the STP 

line (2025-2035), benefi ting from knowledge 

learned from Solar-B and SDO.

Reconnection and Microscale Probe (RAM)

The Reconnection and Microscale mission is 

a next generation, high resolution solar mission 

focused on understanding the basic smallscale processes in hot magnetized plasmas 

that are ubiquitous throughout the universe. 

In hot magnetized plasmas the physical processes governing the dynamics take place on 

remarkably small spatial and temporal scales. 

RAM addresses several fundamental questions, such as what are the mechanisms and 
95

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

magnetic topology that lead to reconnection, 

what micro-scale instabilities lead to global effects and how do magnetic stresses form and 

release in the solar corona? RAM includes a 

0.02 arcsec/pixel EUV imaging telescope, a 0.1 

arcsec/pixel UV/EUV imaging spectrograph, 

and a small x-ray calorimeter to perform simultaneous high resolution imaging and imaging 

spectroscopy to understand the small scale 

dynamic processes and mechanisms of reconnection on the Sun.

RAM addresses fundamentally important 

questions and issues related understanding 

magnetic reconnection and micro-scale instabilities on the Sun. 

RAM should fl y as one of the fi rst missions in 

Phase 3 of the STP line (2020-2025), benefi ting from knowledge gained from Solar-B and 

SDO. 

Solar Heliospheric & Interplanetary Environment Lookout for Deep Space (SHIELDS)

SHIELDS is a new mission concept developed specifi cally in response to the Vision for 

Exploration to help ensure the safety and productivity of human and robotic explorers. 

SHIELDS places two spacecraft in fi xed locations 120 ̊ from Earth in order to view the 

entire solar surface and to determine the direction of propagation of CMEs anywhere in 

the inner heliosphere. Remote sensing instruments include coronagraphs (for observing 

CME onset and propagation), magnetographs 

(to observes evolution of the surface magnetic 

fi elds and active regions) and EUV telescopes 

(to observe fl are activity). Observations of the 

entire solar surface should help enable the predictability of longer periods that are “all clear” 

of solar activity (Objective J). The spacecraft 

would also carry in situ instruments similar to 

those on STEREO and Farside Sentinel to observe the CMEs and associated solar energetic 

particles, also in support of Objective J. 

This mission could replace the Farside Sentinel by providing the farside views of the Sun. 

To provide the helioseismology needed to understand the dynamo and origins of solar activity (Objective F), a Doppler-magnetograph 

would also be needed. This would be a more 

costly mission than Farside since it uses two 

spacecraft, and, at some point the community 

will decide which of the two to pursue. Like 

Farside, this mission has been placed in Phase 

3. It presumes a similarly capable solar observatory located at Earth. Shields will support 

RAM, SWB, MARS, high latitude solar observations, and provide inputs for studies of impacts on planets other than Earth.

Stellar Imager (SI)

Stellar Imager will obtain the fi rst direct images of surface magnetic structures in sun-like 

stars. It will image the evolving dynamo patterns on nearby stars by repeatedly observing 

them with ~1,000 resolution elements on their 

surface using UV emission to map the magnetic fi eld. SI will achieve at least 30 resolution 

elements across stellar disks with one minute 

time resolution in one or more broad optical 

pass bands.

The power of SI lies in its ability to provide 

information on the dependence of the dynamo 

on stellar properties, and enable by its population study, dynamo model validation within 

years rather than many decades. It therefore 

gives solar physicists a unique ‘laboratory environment’ within which to test predictive models of stellar activity. SI thus addresses the 

goals of the Exploration Initiative under Objective J by improving long-term space weather 

forecasts throughout the heliosphere to guide 

vehicle design and mission planning, and forecasts of extended periods for safe construction 

at Moon, Mars, Earth-Moon L1, Sun-Earth L2, 

and LEO staging orbits. By observing planet 

harboring stars and their evolving environments 

it will also provide an improved understanding 

of formation of planetary systems and habitability zones of extra-solar planets. Stellar Imager provides crucially needed information for 

several of the Heliophysics Objectives by observing patterns of magnetic activity and underlying atmospheric structure of a population 

of stars to compare with the Sun. It supports 

Objective F by enabling an understanding of 

the creation and variability of magnetic dynamos, Objective H by promoting an understanding of the causes and subsequent evolution of 

activity that affects Earth’s space climate and 

environment and how the habitability of planets are affected by solar variability. 
96

HELIOPHYSICS

SI should fl y early in the Phase 3 mission 

window (near 2025) to provide the information 

critical to our planned exploration activities 

as humans head out through the potentially 

dangerous interplanetary environment whose 

character is controlled by the Sun.

Partnership Missions

Aeronomy and Dynamics at Mars (ADAM)

ADAM will determine the direct, dynamic 

coupling of a dusty atmosphere with the solar 

wind. It is a single spacecraft that will orbit 

Mars, taking in situ and remote sensing data 

of the upper atmosphere, ionosphere, and solar wind. Instruments will measure the composition, thermal profi le, and circulation in the 

Martian upper atmosphere. Mars aeronomy 

will determine the sources and sinks of ionospheric plasma, its coupling to other regions of 

the atmosphere, and its to the solar wind. 

The dynamics, evolution, and fate of the 

Mars upper atmosphere address fundamental 

science questions as well as providing pertinent information for manned fl ights to Mars. 

Aerobraking and aerocapture require a detailed 

knowledge of the Martian upper atmosphere, 

as well as an understanding of how and why 

the atmosphere varies, for hazard prediction 

and risk mitigation.

This is a high priority mission with direct 

relevance to the manned fl ight component of 

the Vision for Space Exploration. It should be 

fl own as soon as possible in order to allow time 

for the scientifi c investigations of the Mars upper atmosphere to progress to a point of transferring the lessons learned from ADAM to the 

manned fl ight program with suffi cient lead time 

to impact mission development. Therefore, it 

should be a Phase 1 or early Phase 2 mission.

Jupiter Polar Orbiter/Juno

Juno places a spinning radiation hardened 

spacecraft in polar elliptical orbit around Jupiter at 75° inclination. The payload includes 

fi elds and particles instruments, planetary imagery and radio science. Measurements will 

be made of the jovian auroral acceleration regions and radiation belts, the polar magnetic 

fi eld and plasma waves. Radio occultations of 

the ionosphere and atmosphere will determine 

their characteristics.

Juno will conduct a comparative test of magnetospheric models in a case where planetary 

rotation is dominant over the solar wind interaction in powering the system.

Juno timing relative to other missions is noncritical but the mission is highly complementary to other missions that support Exploration 

of the terrestrial planets, for comparative purposes.

L1-Earth-Sun

The L1 Earth-Sun mission will provide the 

fi rst comprehensive and continuous observation of the Earth’s whole day-side atmosphere, 

together with measurements of the contributions to the critical solar spectral irradiance 

that drive the upper atmosphere.

The Earth-viewing portion of the mission consists of a combination of spectrometers in an 

extended wavelength range (58 nm to 2.4 mm), 

with high spatial resolution on the entire sunlit Earth disk. The solar portion of the mission 

consists of a UV/soft x-ray irradiance spectrometer, an imaging bolometer, and a UV/EUV 

imaging spectrograph to explain the irradiance 

phenomena that affect Earth’s atmosphere by 

providing identifi cation and realistic assessment of the contributions of evolving solar activity features to total spectral irradiance. The 

mission also includes a magnetometer capable 

of high time resolution measurement of magnetic fi eld fl uctuations and shocks, and two energetic particle analyzers capable of measuring 

energy resolved charged particle spectra. 

By observing simultaneously the Earth, the 

Sun, and the solar wind, the L1-Earth-Sun mission will enable the fi rst detailed exploration of 

the couplings within the Earth-Sun system. It 

fulfi lls a fundamental and critical need in the 

Heliophysics strategic plan with cross-cutting 

synergistic objectives relevant to understanding fundamental processes which infl uence 

Earth’s climate as well as strong relevance to 
97

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

the Vision for Exploration by improving our understanding necessary for solar activity prediction and its impact on the Earth. 

The L1-Earth-Sun mission should fl y in the 

early part of Phase 2 in order to maximize overlap with SDO and GEC. SDO provides complimentary information regarding solar energy 

deposition while GEC provides in situ observations of the Earth’s upper atmosphere that 

strongly compliment and partially validate the 

L1-Earth-Sun remote observations. Flying L1-

Earth-Sun in early Phase 2 also permits the 

timely replacement of key existing assets at 

L1.

Lunar Reconnaissance Orbiter (LRO)

LRO is conceived as an advance exploration of the Moon to prepare for a human return 

there with longer duration visits than previously achieved. It will contain an investigation for 

monitoring the radiation environment that will 

be encountered by astronaut-explorers. 

LRO measurements will provide important 

information about the practical consequences 

of cosmic ray, solar energetic particles, and 

magnetotail particle acceleration for long term 

human presence on the moon. 

LRO is needed in the near term to refresh 

and update our knowledge of the moon and 

its environments. The radiation environment in 

particular needs to be better documented, particularly for storm events in which potentially 

lethal radiation levels are expected.

Mars Atmospheric Reconnaissance Survey (MARS)

The MARS mission will provide a robust assessment of the upper atmosphere of Mars to 

enable safe human space fl ight to that planet. 

It will consist of a comprehensive package of in 

situ and remote sensing instruments to quantify the dynamics and chemistry throughout the 

Mars atmosphere. It could be one or several 

spacecraft, depending on what is thought to 

be needed to resolve the remaining questions 

about the Mars space environment.

This mission will provide as complete a set of 

measurements as possible to answer any remaining questions about the Mars upper atmosphere and its interaction with the solar wind 

before manned fl ights to Mars begin.

It should fl y after ADAM, but before astronauts go to Mars. Therefore, it is part of the 

Phase 3 mission queue.

Mars Science Laboratory (MSL)

MSL, the next NASA Mars rover mission, is 

scheduled to launch in 2009 with the overall 

science objective to explore and quantitatively 

assess a potential habitat on Mars. The specifi c objectives include assessing the biological potential of the environment, characterizing 

the geology of the landing region, investigating 

planetary processes of relevance to past habitability, including the role of water, and characterizing the broad-spectrum of the surface radiation environment, including galactic cosmic 

radiation, solar proton events, and secondary 

neutrons. The MSL Radiation Assessment 

Detector (RAD) investigation addresses this fi -

nal objective that is of direct relevance to Heliophysics research focus areas J.1, J.4, and 

H.4.

Characterizing and understanding the Martian radiation environment is fundamental to 

quantitatively assessing the habitability of the 

planet and essential for future crewed missions. 

The consequences of both short and long term 

effects of energetic particle radiation on Mars 

are severe. Developing ways to mitigate these 

risks is the single most important challenge to 

preparing for future human exploration of Mars 

(Safe on Mars, National Academy of Sciences, 

2002). RAD will provide the essential precursor information necessary to develop this mitigation strategy. RAD also addresses the radiation effects on biological potential and past 

habitability, as well as keys to understanding 

the chemical alteration of the regolith due to 

impinging space radiation.

New Horizons – the Pluto / Kuiper Belt 

Mission

The Pluto/Kuiper Belt Mission will help us 

understand worlds at the edge of our solar 

system by making the fi rst reconnaissance of 

Pluto and Charon - a “double planet” - and the 

last of the nine planets in our solar system to 
98

HELIOPHYSICS

be visited by spacecraft.

Launched in January 2006, Pluto/Kuiper 

will swing past Jupiter for a gravity boost and 

scientifi c studies in early 2007 and ultimately reach Pluto and its moon, Charon, in July 

2015. Then, as part of an extended mission, 

the spacecraft will head deeper into the Kuiper 

Belt to study one or more of the icy mini-worlds 

in that vast region at least a billion miles beyond 

Neptune’s orbit. The mission will help answer 

basic questions about the surface properties, 

geology, interior makeup, and atmospheres on 

these bodies.

Heliophysics will use this opportunity to obtain in situ measurements of the solar wind interaction with Pluto. Ionization of Pluto’s escaping atmosphere suggests the interaction 

with the solar wind will be similar to that of a 

comet. However, in contrast to cometary interactions that have been measured relatively 

close to the Sun, the weak magnetic fi eld and 

tenuous density of the solar wind in the outer heliosphere imply that the interaction with 

Pluto’s atmosphere will include signifi cant kinetic effects and be highly asymmetric. Understanding these interactions will expand our 

knowledge of the astrophysical processes affecting these bodies and that part of the solar 

system. The SWAP instrument will make measurements of the solar wind deceleration and 

defl ection due to the interaction with Pluto. 

The PEPPSI instrument will measure energetic 

particles produced in the interaction region. 

SWAP will also measure solar wind conditions 

at large distances from the Sun and measure 

the effects of pickup protons from the interstellar medium in the distant heliosphere.

Solar Sail Demo (SSD)

Because of the impossibility of fully validating Solar Sail technology on the ground, the 

application of solar sails to a strategic science 

mission absolutely requires a prior successful 

fl ight validation. Following a Solar Sail Demonstration mission with, say, 40m edge length 

and 25 g/m^2 sails, the technology could be 

readily scaled to meet the needs of the Heliostorm mission (100m edge length and 14 g/m^2 

sails). Once a mission in the class of Heliostorm has fl own, further scale-up could be accomplished for Solar Polar Imager (160-m edge 

length, 12 g/m^2). A third generation solar sail 

would be required for a visionary mission such 

as Interstellar Probe.

The fl ight of a Solar Sail Demo must precede 

the fi rst strategic launch by 5-6 years. A Solar 

Sail Demo mission in mid-2010 would permit 

the fl ight of Heliostorm in 2016 or thereafter. 

Approximately 5 years would then be needed 

after Heliostorm to enable the scale-up to Solar Polar Imager.
Chapter 5.

Heliophysics:

Technology Investments
100

HELIOPHYSICS

Innovation is the engine that drives scientific 

progress, through the development of new 

theories, the invention of new technologies that 

lead to improved measurements , and ultimately 

the emergence of entirely new capabilities. To 

pursue a rigorous study of the Heliophysical 

system we will pursue the development, 

infusion, and study of new technology, both for 

its stimulating effect on science and to enable 

and enhance new missions of exploration. 

Continuing progress in the characterization, 

modeling, and prediction of this system will 

also require technological development in a 

number of key areas.

Heliophysics Capability Requirements

• Simultaneous sampling of space plasmas at 

multiple points with cost-effective means and 

measuring phenomena with higher resolution 

and better coverage to answer specific science 

questions and enable system science;

• Achieving unique vantage points such as 

upstream of the Earth-Sun L1, polar orbit around 

the Sun, or even beyond the heliosphere;

• Developing the next generation of capable, 

affordable instrumentation;

• Enabling the return of vast new data sets 

from anywhere in the solar system; 

• Synthesizing understanding from systemwide measurements using new data analysis 

and visualization techniques.

The highest priority Heliophysics technology needs follow these key focus areas

1. Developing compact, low-cost spacecraft 

and launch systems.

2. Achieving high ∆V propulsion (solar sails). 

3. Designing, building, testing, and validating 

the next generation of instrumentation. 

4. Returning and assimilating large data sets 

from across the solar system.

5. Analysis, data synthesis, modeling, and 

visualization of plasma and neutral space 

environments throughout the solar system.

6. Enabling space weather prediction. 

Table 4.1 shows enabling and enhancing 

technologies for Heliophysics missions. The 

table traces the dependence of these highpriority missions to key technologies and 

also outlines the importance of other areas 

such as avionics, formation flying, structures 

& materials, power, and low cost access to 

space. The number of independent spacecraft 

required for missions increases significantly with 

time. Missions with “clusters” of spacecraft 

(in the range of 2-6 spacecraft) seek lower 

unit costs, while constellations missions such 

as Magnetospheric Constellation (30-36) and 

Solar Wind Buoys (12-15) could be enabled by 

the ST-5 nanosats and the related Instrument 

Development Program projects.

Heliophysics:

Technology Investments 

Chapter 5

Develop Technologies, Data, and Knowledge Systems to Improve 

Future Operational Systems
101

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

The following sections give more detail for 

each of the high-priority technology needs.

1. Developing compact, low-cost spacecraft and launch systems. Because of the 

complexity and large scale of solar system 

plasmas, progress requires clusters or constellations of spacecraft making simultaneous multi-point measurements (e.g., MMS, the 

LWS Storm Probes, Magnetosphere Constellation, GEC, Solar Weather Buoys, and the Inner 

Heliosphere Sentinels). These missions require 

the development of low mass, power, and volume instrumentation as well as low mass, economical spacecraft. Smaller, well integrated, 

spaceflight systems allow these missions to 

be accommodated on a single, and sometimes 

less expensive, launch platform. Good fiscal 

management also requires that we reduce the 

single unit cost of these multi-spacecraft systems; this will require efforts on multiple fronts. 

One important area of technology is the development of low-power electronics (LPE) for the 

instruments and spacecraft bus. One example 

is the CULPRIT Reed-Solomon Encoder on 

ST-5, scheduled for flight validation on ST-5 

in 2006. LPE technology, if available systemwide on a satellite system, can reduce power 

consumption by up to 70%. Power dissipation 

at the component level can be reduced by factors of 50-100 over conventional technology. 

Other areas of high priority technology development include the development of “assembly-line” test and integration methods for the 

constellation-level missions and autonomous 

operation methods to reduce ground operations and to enable reconfiguration of mission 

elements based on internal or external cues. 

Support for further development efforts will be 

provided by the existing Instrument and Technology Development Research Opportunities 

and through the New Millennium Program.

2. Achieving high ∆V propulsion (solar 

sails). Progress in key areas of Heliophysics 

science requires access to unique vantage 

points and in some cases, non-Keplerian orbits. For example, imaging of the Sun’s polar 

regions requires a high-inclination, heliocentric 

orbit. Conventional technology would require 

either 5 years of solar electric propulsion and 

multiple Venus flybys just to reach a 38° inclina-
102

HELIOPHYSICS

tion in the inner heliosphere (as for ESA’s Solar 

Orbiter) or a Jovian gravity assist and conventional propulsion to provide an eccentric 0.25 x 

2.5 AU polar orbit (as for our future Telemachus 

mission). Neither means is as efficient or costeffective as solar sail technology.

The solar sail will use the Sun’s continuous 

supply of photons to propel spacecraft in the 

inner solar system to very high velocities (∆v 

> 50 km/s). They can also provide low-thrust 

propulsion to maintain missions in non-Keplerian orbits not feasible by other means. Solar 

sails will enable three important Heliophysics 

missions:

 • Heliostorm, to provide earlier warnings of 

energetic particles accelerated by CMEs via 

measurements upstream of the Earth-Sun L1 

point;

• Solar Polar Imager, to provide remote sensing of solar poles from an optimal vantage point 

– a circular, 0.5-AU, 75° inclination heliocentric 

orbit;

• Interstellar Probe, to sample interstellar 

space.

The In-Space Propulsion Technologies Project has advanced sail technology considerably 

in recent years. In 2004, two 10-m systems 

were tested in vacuum on the ground, followed 

by two 20-m systems in 2005. This has moved 

the solar sail from the realm of science fiction to 

science fact. The next steps for validation and 

engineering maturation are to deploy and fly a 

hundred-meter-class solar sail. A sail technology demo mission will demonstrate deployment feasibility, that a solar sail provides measurable acceleration, and that it can be steered. 

The technology flight experiment will test and 

validate the models and processes for solar 

sail design, fabrication, deployment, and flight. 

Such models and processes can then be used 

with confidence to design, fabricate, and operate the solar sails needed for strategic science 

missions. A sail demo is a candidate concept 

for the New Millennium Program’s ST9 mission 

scheduled for 2010. Scale-up of the technology to 100-m lengths needed by Heliostorm 

could occur 5-6 years after a successful sail 

demo. Scale-up to still larger sails, such as for 

Solar Polar Imager (~160-m edge length), are 

imaginable from there. Three decades hence, 

the deployment of a larger, high-temperature 

sail required by a mission like Interstellar Probe 

(200-m radius) could be facilitated by human 

crews operating near libration points.

3. Designing, building, testing, and validating the next generation of Heliophysics 

instrumentation. In order to continue to lead 

the world in space science research, NASA 

must not only support the design and validation of space-quality instruments, but also develop and maintain unique instrument development and test facilities. Heliophysics missions 

carry a wide range of instrumentation, some 

designed to make in situ measurements of 

diverse space plasmas and others that make 

remote sensing measurements of plasma processes. The development of new instruments 

and instrument concepts is driven by the need 

to refine and improve instruments, reduce their 

mass and power consumption, and enable new 

measurement techniques. Progress in instrument technology development is needed at all 

technology readiness levels (TRLs), from basic 

concepts for new detectors (e.g. MEMS-based 

(micro-electro-mechanical systems) plasma 

detectors that could be used on MC) to system level demonstrations of improved instruments (e.g. compact Doppler/magnetographs 

for missions such as Doppler).

Specific component technologies that would 

benefit Heliophysics missions include: large 

A solar sail of 20-meter edge length was successfully deployed in vacuum at the Space Power Facility at Plum Brook Station at the Glenn Research 

Center.
103

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

area, deep well CCDs, active pixel sensors, 

low-noise micro-channel plates, foil technology for ENA imagers, high performance EUV 

mirrors, UV blind ENA imagers, low-mass highvoltage power supplies, advanced X-ray optics 

and detectors, thin solid-state energetic particle detectors, compact accurate magnetic 

sensors, and small dead-layer solid state detectors. At the system level, many payloads on 

future Heliophysics missions will be severely 

mass and power constrained (MC and Solar 

Weather Buoys, for example). Technologies 

that reduce sensor and electronics mass and 

power would be particularly useful. In addition 

it is thought that the incredible shear strength 

and impressive electronic properties of carbon 

nanotubes may lead to the development of 

stronger, lighter structural materials and more 

power efficient ionization sources.

The development of these instruments will 

proceed from formulation of new ideas and designs (perhaps based on technologies developed in other fields), basic proof of concept, 

fabrication of test models, laboratory testing, 

and finally flight validation. One important 

avenue for assessing the effects of the variable space environment on potential fight instruments and other technologies is the LWS 

Space Environment Testbed (SET) Program. It 

is important to maintain a balanced program 

that supports all levels of development, particularly the final time-consuming development 

stages that enable instruments to be used inflight.

For some applications, NASA’s low-cost 

access to space (LCAS) program provides an 

ideal avenue for testing and validation. A prime 

example of this paradigm is the development 

of top-hat style plasma detectors. These were 

first conceived for studies of the Earth’s auroral 

regions and were first flown on sounding rockets. The sounding rocket successes led directly to advanced concept instrumentation being 

flown on highly successful magnetospheric 

missions.

4. Returning and assimilating large data 

sets from across the solar system. As our 

exploration of the heliophysical system proceeds, spaceflight missions will place an increasing demand on NASA’s communication 

resources. Missions that image the Sun and 

Earth require high bandwidth communication 

to provide high cadence, high resolution imaging in multiple spectral channels. As remote 

sensing missions are deployed beyond Earth 

orbit, these requirements become more difficult to meet: missions such as SHIELDS or the 

Farside Sentinel will study the Sun from as far 

as 2 AU from the Earth.

Multi-spacecraft missions, both near and 

far from Earth, will also stretch the capabilities 

and operating cultures of the current communications infrastructure. Improvements to our 

communications technologies have begun and 

will enable new science discoveries. Planned 

enhancements to the Deep Space Network 

(DSN), replacing outdated 70m and 34m antenna with arrays of smaller antenna working at 

Ka-band, will increase the available bandwidth 

substantially, while also providing the flexibility to communicate with multiple spacecraft 

simultaneously. Using 200 such antennas, 

for example, would enable kilobit per second 

communications from an Interstellar Probe at 

100 AU.

Optical communication technologies would 

also provide a substantial increase in communication bandwidth and potentially provide the 

capability for high-bandwidth point-to-point 

communication for missions monitoring the interplanetary radiation environment. The next 

generation DSN will eventually provide both 

enhanced RF and optical communications. 

Arrays of small antennas plus the RF improvements (transmitters, inflatable antennas, transponders, for example) together with optical 

communication would provide orders of magnitude increase in science data rates. RF arrays would also enable a significant increase 

in the number of spacecraft that can be supported, particularly in closely spaced clusters.

5. Enabling analysis, data synthesis, modeling, and visualization of plasma and neutral space environments throughout the 

solar system. To effectively model the physical processes controlling our planetary and 

interplanetary environment, information from 

the single spacecraft vantage point is being replaced by multi-spacecraft distributed-observatory methods, and adaptive mission archi-
104

HELIOPHYSICS

tectures termed “Sensor Webs.” These require 

computationally intensive analysis methods 

and data ingestion and assimilation techniques 

appropriate to an incredibly sparsely sampled 

system. Remote space weather predictive capabilities for explorers far from Earth will need 

real-time data assimilative technologies. In 

many missions (e.g. the Inner Heliosphere Sentinels, MagCon, or SEPM) modeling will be an 

integral element of the mission data products. 

Other modeling efforts will assimilate data collected by multiple missions into coherent visualizations of broader physical systems. Critical 

to supporting this future mission operations 

approach is the development of the computing 

infrastructure that makes such synergism possible. Well managed archives, virtual observatory systems, and the vigorous application of 

knowledge support tools are central to many 

of the major Heliophysics science goals to be 

achieved in the coming decades.

 Some groundwork for these activities has 

begun; a confluence of new technologies (internet, XML and web services, broadband networking, high-speed computation, distributed 

grid computing, ontologies and semantic representation) is dramatically changing the data 

landscape. Distributed data and computing 

resources are being linked together for a more 

rigorous approach in the verification and validation of predictive models. Examples include 

the Virtual Observatory programs, which will 

provide pattern and feature recognition to allow 

large datasets to be mined for events, particularly those detected by multiple platforms; the 

Columbia supercomputer, which uses 10,240 

Intel Itanium-2 processors and provides an 

order of magnitude increase in NASA’s computing capability; and the VisBARD project, in 

which space science data is displayed threedimensionally along spacecraft orbits allowing 

rapid determination of vector configurations, 

correlations between measurements at multiple points, and global relationships.

Organizations such as NASA’s Coordinated 

Community Modeling Center (CCMC), the NSFfunded Center for Integrated Space Weather 

Modeling (CISM) and the Center for Space Environment Modeling (CSEM) at the University 

of Michigan are producing integrated models, 

transitioning research tools into operational 

infrastructures, and building software frameworks that link models. These efforts are by 

definition cross-disciplinary, requiring expertise 

in numerical analysis, high-performance computational science, and solar, interplanetary, 

magnetospheric, ionospheric and atmospheric 

physics.

Effective future progress will require a carefully designed systems architecture to provide 

the necessary synergism among robust data 

sets, state-of-the-art models and simulations, 

high-data-rate sensors, and high performance

computing. In the late 20th century, a major 

revolution in chaotic systems and nonlinear

dynamics arose because of a new coupling 

A ViSBARD view of slightly less than a day of 

magnetospheric data including about 40 time series 

along the orbits of nine Heliophysics Great Observatory spacecraft. The magnetic fi eld vectors and 

numerous other scalar quantities can be retrieved 

directly from the internet. The software allows pan, 

zoom, rotation, symbol scaling, and time selection 

and scrolling. This view provides a global picture 

of events that is not possible with large numbers of 

line graphs.

 Labels have been added (CS=current sheet, 

IMF=interplanetary magnetic fi eld). Energetic particle data from the geosynchronous spacecraft are 

overlapping; to see each set individually, a smaller 

time interval must be chosen, in which case the time 

resolution of the glyphs will also increase up to the 

limit of the data. Image courtesy of D.A. Roberts.
105

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

of models and high-performance computing. 

Similarly, we expect that the emerging linkage of rich data sets, high-performance computing, models and sensors will lead to even 

greater scientific understanding of how our 

solar system operates and how we can best 

operate within it. It is within this context that 

the appropriate relationships and investments 

in planning, data access and preservation, and 

analysis and research are best coordinated to 

provide the research-supported space weather 

capability at the core of this roadmap.

6. Enabling Space Weather Prediction.

The Earth Sciences and particularly tropospheric meteorology have long been engaged 

in the process of understanding and simulating 

our atmosphere and oceans in sufficient scope 

and detail to support the prediction of weather. 

Not only can we characterize the long-term 

statistics of atmospheric weather, we can 

also “nowcast” current conditions and foretell 

their short-term development. Moreover, we 

can make forecasts of how the weather will 

evolve over the midterm of several days to a 

few weeks, albeit with accuracy that decreases 

with time in the future. We can even simulate 

and forecast how the climate will respond to 

changes such as the level of anthropogenic 

compounds, volcanic eruptions, or bolide impacts.

To support NASA’s exploration goals, we 

must adopt the space environment across the 

inner solar system as our enlarged domain for 

study, simulation, and prediction. Even though 

a host of new phenomena present themselves 

as challenges for space weather forecasting, 

the basic techniques of data assimilation into 

global circulation models is an element common 

to all atmospheric sciences. In one sense, we 

have simply expanded the definition of “global” and necessarily added the plasma state of 

matter. This process is already well underway 

in the case of geospace weather. NOAA, DoE 

and DoD, along with NASA, have been active 

in this area for decades in the characterization, 

nowcasting, and increasingly, forecasting of 

geospace weather. NASA must now expand 

this purview to the Moon and Mars. 

The regions to be explored include first the 

Moon and cislunar space, then later Mars 

and cismartian space, and eventually the asteroid belt. This requires better knowledge of 

Earth’s upper atmosphere, because returning 

explorers will rely on aerocapture for successful landing. Also needed is an improved predictive knowledge of the radiation belts, which 

have proven to be more variable and volatile 

than was expected from early reconnaissance. 

When astronauts travel beyond the Earth’s 

ionosphere, knowledge of solar energetic particles becomes of paramount importance, as 

indicated by the vulnerability of the Apollo astronauts, who narrowly avoided devastating 

space storms in 1972.

Among the seldom-appreciated features of 

the lunar landscape are the dust fountains that 

exist at the solar terminators. Lunar dust is extremely abrasive and problematic for operation 

of human-tended systems. At Mars, dust and 

Martian meteorology present even more obvious concerns for arriving astronauts. Efforts 

to use aerobraking and aerocapture at Mars 

have been complicated by strong variability of 

the atmosphere, indicating the need for better predictive models of that medium as well. 

In all these areas, human exploration must be 

informed by science to maximize productivity 

and minimize risks. 

Understanding space weather throughout 

the inner solar system becomes more important as astronauts and critical spacecraft systems spend more time away from the sheltering Earth. It will be incumbent upon NASA to 

support the operational resources required. 

The activities described here form a sound research foundation for space weather support. 

We will need greater rigor in the verification 

and validation of predictive models, observations will be required from remote sites, and 

greater computer power must be brought to 

bear on the continuous operation of modeling tools. This all depends upon many infrastructural developments that go beyond what 

is in place today. What must ultimately emerge 

is a research supported operational capability 

directed toward Inner Solar System Environment Services, one that is highly analogous to 

the National Weather Service for tropospheric 

weather or the NOAA Space Environment Center for geospace weather.
106

HELIOPHYSICS
 Chapter 6. Heliophysics: Sun- 

 Solar System Connection Impacts

 - Education and Public Outreach

 - Links with Other NASA Activities

 - Advancing U.S. Scientific, Security, & Economic Interests

 - External Drivers of the NASA Heliophysics Program 
108

HELIOPHYSICS

Sun-Earth Day

Sun-Earth Day is an annual national program supported by the Sun-Earth Connection Education 

Forum (SECEF). Since 2001 the Heliophysics community has shared the science linking the Sun 

and Earth with educators, students, and the general public via informal learning centers, the Web, 

TV, and other media outlets through high-profi le, well supported annual events. NASA science is 

connected to classrooms and museums in real time, and educational resources are disseminated 

via the Web and through NASA centers. In the context of an overarching emphasis on the SunEarth connection, a specifi c theme is created each year to continue to engage the public.

2001 - Having a Solar Blast

2002 - Celebrating the Spring Equinox

2003 - Live from the Aurora

2004 - Venus Transit

2005 - Ancient Observatories: Timeless Knowledge

2006 – Eclipse In a Different Light

Sun-Earth Day activities have broad reach. For example, the 2004 Sun-Earth Day website received 40 million hits in 40 hours. There were 1000 news reports on various TV channels, including 40 interviews with NASA scientists. More than 12,000 packets of educational materials were 

distributed to teachers, museums, and amateur astronomers in support of the 2004 Sun-Earth 

day programming.

As part of the 2005 Sun-Earth Day program, the Ancient Observatories: Timeless Knowledge 

website (sunearthday.nasa.gov) and the Traditions of the Sun website (www.traditionsofthesun.

org) were launched in fall 2004 to allow users to explore Chaco Canyon and other areas. Visited 

500,000 times, these websites also highlight NASA research on the Sun and Native American solar practices within a larger historical and cultural context. Formal education programs engaged 

75,000 teachers and 225,000 students, with all 10 NASA Centers hosting events. 100 NASA 

Explorer Schools also participated. Informal education efforts included programs hosted by 24 

museums across the country and training for Girl Scout Master Leaders who ultimately engaged 

some 10,000 girl scouts in Sun-Earth Day activities. The culminating event for Sun-Earth Day 

2005 was a live bilingual webcast from Chichen Itza, Mexico that reached thousands of Hispanic 

and Native American participants.

 

Wijiji, Chaco Canyon: This 

photo was taken from inside 

the northwestern corner of 

the Wijiji Great House. It is 

believed that this site may 

have been used as a calendar station for the winter solstice. On December 

4-5 the rising sun appears 

in the leftmost region of 

the deepest notch on the 

horizon. Over the next 16-

17 days the rising sun appears further and further to 

the right until fi nally reaching the rightmost region of 

the notch on the winter solstice. Photo Credit: Troy 

Cline
109

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

Unique Education and Public Outreach (E/PO) 

opportunities are associated with Sun-Solar 

System connection science. The top-level 

objectives, research focus areas, and science 

achievements that constitute the Heliophysics 

Strategic Roadmap for the next 30 years provide powerful opportunities for Education and 

Public Outreach from the Heliophysics science 

community.

E/PO activities stemming from the science 

achievements should be developed to support 

the following fi ve themes:

• NASA keeps me informed about what’s 

going on with the Sun

• The Solar System is an astrophysical laboratory for NASA

• NASA science helps us protect our society 

from hazardous space weather

• NASA science helps us understand climate change

• NASA science helps keep space explorers 

safe and supports exploration activities

These messages are of high interest and relevance to the public and they span the range of 

scientifi c activity engaged in by the Heliophysics community. The traceability to the Heliophysics science and exploration objectives is 

clear. Chart 6.1 below shows the logical fl owdown outlining how the Heliophysics scientifi c 

objectives and associated research focus areas lead to the fi ve E/PO themes. The themes 

then inform the implementation of programs of 

formal and informal education and public outreach.

The anticipated scientifi c achievements articulated in Chapter 3 for each of the next three 

decades that relate most clearly to these 

themes are shown in Table 6.2A. The themes 

and achievements are color coded to show the 

most direct links. Table 6.2B also identifi es the 

missions that are most closely associated with 

the achievements and themes.

Education and Public Outreach

Chart 6.1. Logical Flow from Heliophysical Science to E/PO Themes and Implementation
110

HELIOPHYSICS

Table 6.2A. Science Achievements from the Roadmap support Heliophysics E/PO Themes

Expanded and invigorated education and 

public outreach are essential to the achievement of the Vision for Space Exploration 

(VSE). NASA’s Strategic Objective for Education and Public Outreach is to “Use NASA 

missions and other activities to inspire and 

motivate the nation’s students and teachers, to 

engage and educate the public, and to advance 

the scientifi c and technological capabilities 

of the nation.” The Heliophysics community 

emphasizes the connection between achievement of this strategic objective and the Vision 

for Space Exploration. The development of 

the workforce needed to achieve NASA’s objectives requires that E/PO activities engage 

young people and capture their interest and 

passion. We need to increase the capacity of 

our nation’s education systems, both in school 

(Formal: K-16) and out of school (Informal), to 

prepare students for scientifi c and engineering 

careers.

Heliophysics science and mission activities 

provide valuable hooks for E/PO. For example, 

learning to predict the variable radiation hazards and space weather conditions that our 

astronauts and robots will encounter on excursions to the Moon, Mars, and elsewhere is very 

exciting scientifi c work that the public will want 

to know about. New advances using our Sun 

and solar system as astrophysical laboratories 

will fuel the generation of authentic, sciencerich education resources that will increase the 

capacity of the nation’s education systems.

Developing the workforce to implement the 

VSE will require substantial focus on underrepresented communities. The current demographic makeup of the science and engineering workforce in the USA is overwhelmingly 

white. Population projections to 2025 indicate 

that the percentage of traditionally underrepresented communities will increase. Successful 

E/PO efforts will benefi t substantially by reaching presently under-represented groups.

An exciting example of E/PO targeted at un-
111

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

Table 6.2B. Heliophysics recommended missions identifi ed with Heliophysics E/PO Themes

derrepresented communities is NASA’s SunEarth Connection Education Forum’s (SECEF) 

Sun-Earth Day programming for 2005: Ancient 

Observatories: Timeless Knowledge (see box). 

This broad program allowed NASA and Native American astrophysicists to share their research into the efforts of ancient cultures to understand the Sun and its affects on their lives, 

highlighting the importance of the Sun across 

the ages. Through programs such as these, 

Heliophysics scientists convey NASA’s mission 

and research program activities to diverse audiences. Both English and Spanish language 

materials have been disseminated.
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HELIOPHYSICS

Examples of Strong Mission E/PO Programs: SOHO & IMAGE

SOHO, the Solar and Heliospheric Observatory mission, runs a vigorous program to disseminate images 

to informal audiences and to the media, regularly distributing images of the Sun from the LASCO, EIT, and 

MDI instruments in near real time on the Web, and weekly to the American Museum of Natural History’s 

AstroBulletin, and to a variety of media publishers, including National Geographic. Sun and space weather 

3-D/motion postcards (lenticulars) are a very popular tool for engaging students and the general public. 

Over 200,000 lenticulars have been distributed.

SOHO sponsors two model collaborations with educators and students. FiMS (Fellowships in Mathematics and Science), a partnership grant with the Pennsylvania Department of Education (in 3 school systems), 

provides a strong example of the power of working directly with the local formal education system. SOHO 

educators and scientists work with their local teachers to increase content knowledge and support their 

ability to develop and implement inquiry-based lessons tied to state standards and the current curriculum. 

The Endeavour program, a collaboration between SOHO/NASA and 18 school systems, gives teams of 

students real-life NASA problems to research. Students are supported by teacher team leaders that have 

been exposed to the content and training through professional development.

Efforts to broaden the reach of SOHO’s E/PO efforts, including English and Spanish versions of presentations on the Dynamic Sun CD and of the build-your-own-spectroscope poster, have been very effective. In 

addition, SOHO brings the science and exploration of our Sun to the visually impaired through their groundbreaking “Touch the Sun” book.

IMAGE, the Imager for Magnetosphere-to-Aurora Global Exploration mission, has been at the forefront 

of providing teachers with math and space science classroom activities. The IMAGE team works hard to 

improve public awareness of space weather impacts and to improve student math skills. Its annual space 

math workbooks have been distributed to over 75,000 teachers through their Space Weather CD and their 

popular POETRY website (Public Outreach, Education, Teaching and Reaching Youth; image.gsfc.nasa.

gov/poetry). The Soda Bottle Magnetometer , designed by POETRY in 1997, has been a popular hands-on 

activity for millions of students and is a key element in the Student Observing Network (SON).

Recently, IMAGE created a new program called the ‘Space Science Problem of the Week’ that is distributed electronically to over 5000 teachers. These extra-credit math problems cover the entire gamut of science and engineering problems and give grade 7-12 students a hands-on and authentic math experience 

in solving key problems in Heliophysics science. IMAGE also sponsors the INSPIRE project, which has 

allowed students of over 2000 high school teachers from North America and around the world to listen-in to 

low frequency radio signals called whistlers, that are made by Earth’s magnetic fi eld in space.

In informal education, IMAGE has created museum kiosks at the Houston Museum of Science, planetarium programs such as ‘Force Five’, and has contributed to the SECEF Space Weather museum exhibit, 

which collectively have brought Heliophysics science and research to over 200,000 people annually.
113

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

E/PO Challenges and Recommendations

Signifi cant opportunities exist to extend the impact of Heliophysics science and related mission activities to engage and inspire students in formal education settings, audiences at informal 

learning centers, and the general public across the nation via the press and other communication 

outlets. Table 6.3 presents a summary of challenges to effective E/PO. The remainder of this 

section presents a series of recommendations to expand and enhance NASA’s E/PO activities.

Table 6.3. Challenges and recommendations to effective E/PO

Challenge Recommendation

E/PO practices vary widely across NASA. This is a 

disadvantage for both PIs and for audiences. PIs 

are often in the position of inventing their own E/PO 

programs, products and activities and audiences 

need to constantly relearn how to take advantage of 

these efforts.

Generate uniform, standards-based product lines 

with themed content for schools, museums, and 

science centers, as well as the press and media 

outlets. Invest production resources in development of core products that can be used appropriately by a range of E/PO partners.

The formal, K-12 science education system needs 

strong connections with NASA’s scientifi c, engineering and technological enterprises if it is going to 

play a suffi cient role in preparing the science and 

engineering workforce required to implement and 

achieve the Vision for Space Exploration.

Correlate NASA’s activities, enterprise-wide, with 

national science standards (e.g. National Science 

Education Standards of the NRC and Benchmarks 

for Scientifi c Literacy, Project 2061) to develop a 

roadmap for infusing NASA resources into the formal K-12 system. Middle School presents a particular opportunity due to the level of concepts mastered; more fl exible curricula can be designed for 

use in High School. Develop templates for products, programs and professional development that, 

combined with the roadmap, effectively connect 

NASA’s ongoing, authentic activities to classrooms 

for educators and learners.

Too few undergraduates choose physics-based careers in particular and science and engineering careers in general. Extend focus from K-12 to K-16 

to integrate cutting-edge Heliophysics topics into 

undergraduate physics courses along with other relevant NASA content.

Broad dissemination is required to achieve impact. 

Requiring individual PIs and Missions to create 

their own dissemination channels is burdensome 

and lessens impact. Expand existing and develop 

new centrally supported channels for dissemination 

that mission and research-based E/PO can use to 

reach full range of audiences.

There are limited opportunities for undergraduates, 

graduate students, and early career scientists to obtain the intense hands-on training that is required to 

design, build, and manage the next generation of 

space science hardware.

Sub-orbital rocket and balloon payloads are a proven, cost-effective method for “high context” training 

of space scientists, but resources for these programs have been decreasing. It is imperative to 

reverse this trend in order to increase training opportunities.

Use of E/PO investments is not maximized due to 

lack of sustained support and dissemination.

Make sustained investment over time in Web-based 

dissemination of NASA materials. Use of bestpractice templates to create materials will facilitate 

maintaining currency.
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HELIOPHYSICS

Integrate messages and utilize best-practice strategies for effective E/PO. Unifi cation 

of NASA’s scientifi c enterprise into the Science 

Mission Directorate presents opportunities for 

science education efforts all across NASA, including Heliophysics. While each NASA division, mission, and individual contributes unique 

content and experiences to E/PO; integration 

into a single science directorate has the potential to be more effective in terms of message 

and approach. Moving forward, it won’t matter 

if it’s Space Science, Earth Science, Geophysics, Biological Research, or something else 

– the single ‘brand’ will be exciting, relevant 

NASA science. Furthermore, approaches to 

bring this content to the broadest possible audiences can take advantage of the best strategies of each of the former enterprises to create 

the strongest possible suites of products and 

programs. E/PO programs include the development of tools for evaluating quality and impact, in order to identify and disseminate best 

practices in E/PO.

The Heliophysics scientifi c community is vigorously engaged in E/PO and current efforts align 

well with SMD’s education goals and priorities. 

Our E/PO programs already encourage the scientifi c community to share the excitement of 

their discoveries with the public. The programs 

enhance the quality of science, mathematics, 

and technology education. Efforts align with 

NASA’s Science Mission Directorate’s education goals and priorities to inspire and motivate 

students to pursue careers in science, technology, engineering and mathematics (STEM) and 

to engage the public in shaping and sharing 

the experience of exploration and discovery.

E/PO activities are currently integrated throughout all the Heliophysics fl ight missions and 

research programs. As a result, a signifi cant 

fraction of the Heliophysics research community contributes to a broad public understanding of the science and is directly involved in 

education at the pre-college and college level. 

Graduate student participation in Heliophysics 

research programs are enhanced by the Graduate Student Research Program, a cooperative 

program between NASA Education and the 

Science Mission Directorate. Vigorous E/PO 

programs also stem directly from various science programs within the Heliophysics community to effectively serve the needs of local 

communities.

Centralized efforts such as the Sun-Earth Connection Education Forum (SECEF), a partnership between NASA Goddard Space Flight 

Center and the University of California at 

Berkeley, strive to facilitate the involvement of 

Heliophysics scientists in E/PO activities and 

to establish strong and lasting partnerships 

with formal and informal education communities. These centralized efforts seek to develop 

a national network to identify high-leverage 

education and outreach opportunities and to 

support long-term partnerships. SECEF helps 

provide ready access to the products of Heliophysics science education and outreach programs. They also promote the participation of 

under-served and under-utilized groups in the 

Heliophysics science program by providing 

new opportunities for minorities and minority 

universities to compete for and participate in 

Heliophysics science missions, research, and 

education programs.

Provide education and professional development resources for formal and informal 

science education that are consistent and 

coherent across the entire NASA enterprise. 

NASA needs to coordinate and centralize its 

educational outreach to better enable E/PO 

partners to take advantage of Heliophysics 

science to engage their audiences. Educators in the K-12 arena require standards-based 

educational resources coupled with high-quality professional development offerings to take 

advantage of NASA’s constant stream of fresh, 

current, authentic scientifi c discovery and engineering activities. NASA creates a wide array 

of resources such as informational websites, 

animated simulations, sets of data visualizations, teaching guides, sets of standardsbased curriculum activities, on-line courses, 

video conferences, interactive modules, posters, opportunities to interact on line and by video with scientists, engineers and technicians, 

opportunities for student research, and regular 

science updates. These must be coupled with 

appropriate professional development to ensure that educators always have NASA in their 

tool-kit for effective science education. Part-
115

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

nership with professional organizations such 

as the National Science Teachers Association 

has proven effective for NASA, and should be 

expanded.

Heliophysics and other NASA missions and 

activities likewise provide wonderful springboards for learning in the informal setting. 

However, both educators and exhibit planners 

in informal settings typically fi nd using each 

NASA opportunity requires a signifi cant effort 

simply to ramp up, since there is little consistency in what NASA produces, from center to 

center, or from mission to mission. It would be 

tremendously helpful for each NASA activity to 

have a standard set of resources with common 

interfaces and similar formats that are reasonably consistent from activity to activity, e.g., an 

informational website, an annotated simulation, 

a set of opportunities to interact with scientists, engineers and technicians, and activities 

for out-of-school settings. Professional development is also required for informal educators; 

and current partnership efforts with professional organizations such as the Association of 

Science and Technology Centers have proven 

effective, and should be expanded.

Flexibility is, of course, essential. The unique 

opportunities and requirements of each activity 

should be exploited, technologies will evolve, 

and evaluation will inform revision. However, 

the ability to count on a standard package 

would likely reduce the learning curve for users and increase the ultimate usability and use 

of the resources. SECEF is a good example 

of the value of a coordinated national effort to 

develop and support E/PO activities; emphasis 

on standardized packages will strengthen this 

approach.

Promote and support the integration of the 

Heliophysics-related content more fully into 

standards-based K-12 science curricula. 

National science education standards provide 

direct opportunity to take advantage of Heliophysics science specifi cally and NASA science 

in general to improve science education on a 

national level. In this era of standards-based 

curriculum and high stakes testing, what gets 

taught is what is required in the curriculum and 

thus assessed on tests. State science curriculum standards generally map to these national 

standards, and thus tremendous opportunity 

exists for current Heliophysics science content 

to enrich and infuse these curricula. Infl uential 

science education standards such as the National Science Education Standards (National 

Research Council) and the 2061 Benchmarks 

for Science Literacy (AAAS) place substantial emphasis on Heliophysics related science 

concepts from the earliest grades through high 

school. The 2061 Benchmarks, for example, 

posit that in order to achieve scientifi c literacy 

students in grades K-2 master concepts such 

as ‘The Sun can be seen only in the daytime, 

but the moon can be seen sometimes in day 

and sometimes in night’ (4A/2); students in 

grades 3-5 further expand this understanding 

to ‘Stars are like the Sun, some being smaller and some larger, but so far away they look 

like points of light’ (4A/5); in grades 6-8 they 

learn that ‘The Sun is a medium-sized star located near the edge of a disc-shaped galaxy 

of stars, ...’ (4A/1), and that ‘Telescopes reveal 

that the Sun has dark spots’ (10A/2); and by 

high school, that ‘Increasingly sophisticated 

technology is used to learn about the universe. 

Visual, radio, and X-ray telescopes collect information from across the entire spectrum of 

electromagnetic waves; ... (4A/3). This progression of understanding highlights the role of 

understanding the Sun at many levels in developing scientifi c literacy. Heliophysics research 

provides vivid, authentic examples to promote 

student mastery of these concepts.

The entire NASA enterprise could, for example, be mapped to the Benchmarks for Scientifi c Literacy, and/or the National Science 

Education Standards. The result would be a 

roadmap in itself for integrating NASA science 

and engineering activities into science curricula across the nation.

Extend focus to higher education in order 

to ensure adequate numbers of trained scientists and engineers for the Heliophysics 

community and the rest of NASA to achieve 

the VSE. Solar and space physics needs a 

national effort that relates the exciting applications in our fi eld to specifi c curricular needs of 

introductory physics and astronomy – classes 
116

HELIOPHYSICS

with substantial enrollments at just about every 

college in the nation. The excitement of space 

science can entrain and encourage more undergraduates through physics, math and engineering programs at the university level. This 

will compliment current programs geared towards providing early research experience 

(such as NSF’s REU program) that are very important for attracting non-traditional students 

into the workforce. Attention needs to be paid 

to how the space physics workforce is developed – where do students come from and why 

– in order to ensure suffi cient numbers for a 

healthy scientifi c community able to achieve 

NASA’s goals.

Increase availability of “high context” 

learning experiences for undergraduates, 

graduate students, and early-career scientists in order to train the next generation 

of space scientists. There are multiple ways 

to provide genuine, practical experience for 

new experimenters to participate. The Low 

Cost Access to Space program (see Chapter 3) has historically been an important part 

of this process and should be strengthened. 

New program possibilities include a “Hardware 

Apprenticeship Program” with a competition 

similar to the NSF Career program. Recent 

PhDs working at universities could be funded for a 3-5 year hardware development and 

fl ight program. This would both train and sustain them during a crucial stage of their space 

science career. Another possibility is a NASA 

SMD funded undergraduate/graduate course 

in Space Research, which would take student 

teams through the design, construction, and 

fl ight of a small sub-orbital payload. A program such as this could increase the engineering workforce available to NASA as well as the 

number of hardware-trained space scientists.

Increases in the cost, complexity, and management of space missions have made it diffi cult to use them to signifi cantly support workforce training. The sub-orbital programs are 

still a cost-effective way of giving future space 

scientists and engineers a real world experience that contains all of the elements of a full 

space fl ight, and therefore provides one of the 

few methods for widening the scientist and engineer pipeline for NASA

Enhance existing and create new distribution channels for E/PO efforts: products, 

programs, and messages. It is not realistic 

or effective to make individual Heliophysics 

PIs responsible for building and sustaining 

their own dissemination relationships. This 

is not to say that individual PIs should not be 

encouraged to go into classrooms, make public presentations, or appear in the media. We 

recommend that NASA develop a spectrum of 

dissemination options that are supported and 

sustained centrally. In addition, NASA should 

support best practice use of World Wide Web 

for keeping products current and leveraging 

development efforts over time.

Emphasize unique learning opportunities 

that Heliophysics-related content can provide; in particular, the visualization of data 

is essential for advancing science learning 

and the nation’s scientifi c capacity. Expand 

efforts already underway to create high production-value media programs around the scientifi c assets of NASA, including the Sun-Earth 

System. Fully digital space shows; large-format media projections, television productions, 

etc. are powerful vehicles for promoting public understanding of complex phenomena and 

teaching students of all ages the critical skills 

for 21st century science: collecting, analyzing, visualizing and communicating data and 

constructing, manipulating and interpreting 

scientifi c models and simulations. Increased 

efforts taking advantage of partnerships with 

media production groups and distributors will 

contribute substantially to achieving greater 

impact for E/PO programs.

Focus on innovative external partnerships to create programs that reach a broad 

range of the public. Through leveraging partnerships with informal science learning centers 

(museums, planetaria, science centers), national parks, community groups (Girl Scouts), 

publishers, and the media, Heliophysics science can be more widely disseminated by taking advantage of existing channels. For example, NASA has connected very effectively with 

the National Parks to provide content on the 

aurora and noctilucent clouds for summer pro-
117

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

grams in Alaska and information about the Sun 

in support of educational programs at parks in 

the southwest. Such programs provide amplifi ed impact by enhancing the capacity of 

established channels to engage, excite and 

educate the public with science and engineering content. New avenues should also be explored, for example, products developed with 

the gaming industry could engage the public, 

young and old, in the Vision for Space Exploration.

To maximize impact of Heliophysics science for E/PO, efforts should take advantage of opportunities that exist at the intersection of the “formal” and “informal” 

education sectors. Too often in education 

policy and strategy, schools and museums are 

viewed independently, with isolated objectives 

and separate strands of efforts. While there 

are clear differences, substantial connections 

and overlaps exist. Many informal science 

education institutions already operate at the 

intersection of the two sectors – offering substantive professional development for teachers, providing learning experiences and fi eld 

trips for classes, delivering after-school services, and developing and distributing curriculum materials and resources. A key strength 

of these institutions is local knowledge. The 

formal education landscape is highly variable 

and this local knowledge is key to successful 

connections between science and engineering-rich agencies, such as NASA, and science 

and engineering education efforts in the formal 

setting. NASA E/PO should take advantage of 

the existing connections and overlap between 

the formal and informal education arenas.

Develop better coordination with Public Affairs to maximize the effectiveness of 

E/PO efforts. Consistent messaging is essential to effective communication, and effective 

communication is key to strong E/PO. More 

substantial overlap should occur between 

Public Outreach and Public Affairs (PA). These 

activities are distinct: Public Outreach from 

Heliophysics covers a broad range of topics 

and targets the public directly, whereas Public Affairs communicates specifi cally new and 

current discoveries to the media for dissemination to the public. However, the visual and 

editorial resources required by the two are very 

similar, and thus we recommend that Public 

Affairs team up with the E/PO group early in 

order to develop the same core messages and 

visual assets. This will facilitate getting better media coverage of scientifi c results and 

publicizing exciting E/PO events. It will also 

strengthen education programs because they 

can use the visual and editorial assets developed for Public Affairs and Public Outreach.

E/PO efforts need to focus on outreach, not 

advertisement. While it is important to raise 

public awareness of Heliophysics missions 

and activities, E/PO funds must be invested in 

products and programs that go beyond advertisement and truly engage and inform. Thus 

we strongly discourage the use of E/PO funds 

for lanyards, pins, etc., that are solely designed 

to advertise a mission.

Educate the public via outreach through 

informal and formal channels about the 

risks inherent in the exploration of space. 

As NASA pursues Return to Flight and the Exploration Vision, it will be very important for the 

public to be aware of the risks associated with 

these activities. In the event that accidents occur that result in setbacks in mission activities 

or even in the tragic loss of life, the public will 

be best able to respond appropriately if they 

were aware up front of the risks involved.

Shift in management and implementation 

of SMD E/PO. NASA E/PO has made a remarkable impact through commitment of substantial funds over the past decade or more. 

The value of having the scientifi c community 

intimately involved in the development and implementation of E/PO products and programs 

cannot be over emphasized. Thus we strongly 

advocate maintaining the established commitment of funds for E/PO.

For smaller efforts NASA should continue to 

offer supplements for which individual PIs can 

apply to support E/PO activities that stem from 

their scientifi c research and mission activities. 

New E/PO activities should map to one of the 
118

HELIOPHYSICS

fi ve themes articulated above. Themes will be 

modifi ed and replaced as part of future Heliophysics strategic planning activities. However, 

rather than expect each investigator to invent 

a new set of E/PO activities, we recommend 

that the allocation of E/PO funds ordinarily be 

linked to efforts consonant with a broad portfolio of approved, adaptable E/PO programs 

and product templates from which the PI may 

select. Further, NASA should require that dissemination ordinarily be through one or more 

of NASA’s approved and maintained channels.

The portfolio of approved E/PO product and 

program suites should be developed using existing successful E/PO efforts as models, as 

well as taking advantage of best practices in 

formal and informal education. It is very important that these be developed through collaboration between the Science Directorate and the 

Offi ce of Education. It also very important that 

investigators funded by the Science Directorate play a signifi cant role in the choice of allocation of their E/PO funds.

At the mission scale, we encourage better 

coordination between the mission EPO and 

the overall EPO program. This may include an 

adaptable selection of approved product and 

program suites. PIs should identify the Heliophysics E/PO theme(s) to which their activities map and be required to utilize appropriate 

dissemination strategies and channels. While 

individual teams must demonstrate a genuine 

commitment to E/PO, and teams with particular interest and expertise in developing new 

types of E/PO should be encouraged and supported, as a general rule PIs should not be burdened with inventing E/PO programs as they 

are putting together their mission proposals. 

In essence, science proposals funded by the 

Science Mission Directorate should continue 

to be selected on the basis of their scientifi c 

merit. Funding for E/PO derived from these 

scientifi c missions and programs should then 

be approved by and selected using agency 

guidelines, perhaps at the mission confi rmation review.

The PIs should manage their own E/PO programs and help oversee the allocation of mission E/PO funds.

Sustained public engagement with and 

support of the Vision for Space Exploration 

will be will be essential to NASA’s success 

over the next 30 years. The Heliophysics 

community is excited to collaborate in the E/

PO efforts designed to bring the public along 

on the VSE. Progress in Heliophysics science 

will not only enable the safe and productive 

transit and landing of human and robotic explorers on other bodies in our Solar System; 

it will also advance our capacity to mitigate 

hazardous space weather impacts and global 

climate change at Earth; and it will continue to 

open new frontiers of scientifi c discovery about 

the Earth, the Solar System, and the Universe.
119

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 
120

HELIOPHYSICS

Links Between the Heliophysics Strategic 

Roadmap and other NASA Strategic Roadmaps

Heliophysics, the science of the Sun-Solar 

System connection, focuses on space plasma 

physics in our cosmic neighborhood. It encompasses the Sun and the processes and 

phenomena that determine the space environment near the Sun, in the Earth-Moon system, 

in the vicinity of other solar system bodies, and 

throughout interplanetary space to the very 

boundary with interstellar space.

To the degree that the space environment 

matters to people or their technological systems, whether on Earth or in space, Heliophysics has application to human activities. 

Penetrating energetic particles and photons 

produced by acceleration and radiation processes in space plasmas profoundly and adversely impact any exposed living organism 

through cellular damage and mutation. They 

also adversely impact exposed technological systems through episodic and cumulative 

damage to microcircuits and cumulative degradation of materials. Therefore, the processes 

that produce and transport energetic radiation 

are of direct interest to modern humans.

The situation for long-duration space fl ight 

is somewhat analogous to deep-ocean operations of naval ships. Vessels are designed to 

survive in various climatic conditions; yet the 

weather, which can be extreme, limits operations and determines how vessels should be 

confi gured in any situation. Similarly, operations in space, such as extravehicular activities 

(EVAs), maneuvers, operations on lunar and 

planetary surfaces, and fi nding safe harbor, 

will depend on space weather. Space weather 

in the vicinity of planetary bodies affects the 

state of the upper atmosphere, where density and wind distribution are critical to vehicle 

aerocapture, ascent, and descent scenarios. 

Space weather also alters the state of planetary ionospheres where spatial and temporal 

electron density distributions infl uence navigation and high band-width communications. As 

for terrestrial weather, space weather awareness, understanding, and prediction will be esLinks Between Heliophysics and Other 

NASA Activities

NASA NATIONAL OBJECTIVES

Implement a sustained and affordable human and robotic program to explore the solar system and beyond

Extend human presence across the solar system, starting with a human return to the Moon by the year 2020, 

in preparation for human exploration of Mars and other 

destinations

Develop innovative technologies, knowledge and infrastructure both to explore and to support decisions 

about the destinations for human exploration 

Promote international and commercial participation in 

exploration to further U.S. scientifi c, security, and economic interests

Study the Earth system from space and develop new 

space-based and related capabilities for this purpose

NASA STRATEGIC 

OBJECTIVE #15

Explore the Sun-Earth system to understand the Sun and its effects on Earth, the 

solar system, and the space environmental conditions that will be experienced by 

human explorers, and demonstrate technologies that can improve future operational systems.

NASA’s Advanced Planning and Integration Offi ce (APIO) developed the statement of NASA Strategic Objective #15 for the Heliophysics division to support NASA’s Guiding National Objectives (in NASA’s Direction 

for 2005 and Beyond, NASA HQ, February, 2005) 
121

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

sential enabling activities for space exploration 

operations. Therefore, we recognize strategic 

linkages between the Heliophysics Roadmap 

and all three Exploration Roadmaps (Lunar exploration, Mars exploration, and the development of the Crew Exploration Vehicle).

The effects of space weather on Earth’s atmosphere are of special interest. Enhanced 

ozone depletion is a documented consequence 

of energetic particle precipitation. We are 

aware of space plasma processes that erode 

the Earth’s atmosphere, removing ~103 kg of 

hydrogen and oxygen daily, and vastly greater 

quantities during space storms. We have performed computer simulations that imply even 

greater loss of atmospheric constituents at 

Mars, which lacks the shielding provided by 

an intrinsic planetary magnetic fi eld. The potential role of local space weather and/or solar 

variability in terrestrial climate change is as yet 

unknown. The state of the Earth’s ionosphere 

is thought to be subtly modifi ed by terrestrial 

seismic activity. Quantitative determination of 

the intrinsic terrestrial magnetic fi eld requires 

an accurate accounting of fi eld sources external to the solid Earth. These external sources 

are dominated by electrical currents carried 

in the space plasmas surrounding the Earth. 

For these reasons, we also recognize strategic 

linkages between the Heliophysics Roadmap 

and the Earth Science Roadmap.

The same processes and phenomena that 

drive space weather in our solar system also 

shape environments throughout the universe. 

We have a typical, variable, main sequence 

star (the Sun) in our cosmic back yard. We 

live on a habitable planet that is largely protected from hazardous elements of our local 

space environment by a magnetic shield (the 

magnetosphere), a feature not shared by all astronomical, or even planetary bodies. As we 

try to understand the remote universe and its 

potential to evolve life, it is imperative that we 

take as full account as possible of the lessons 

we learn from the specimens we can virtually 

touch with our hands. Therefore, we recognize 

important linkages between the Heliophysics 

Roadmap and other Science Roadmaps that 

seek to understand nearby planetary systems 

and the larger universe and also between the 

Heliophysics Roadmap and the Roadmap to 

search for other habitable planets.
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HELIOPHYSICS

Links Between the Heliophysics Strategic 

Roadmap and NASA Capability Roadmaps

Continued progress in Heliophysics requires 

new capabilities based on the development of 

new technology. Future technology needs are 

driven by diverse requirements. Cluster and 

constellation missions are required to simultaneously sample large-scale space plasmas at 

multiple points (Magnetospheric Constellation, 

Inner Heliospheric Sentinels, Solar Weather 

Buoys, Dayside Boundary Layer Constellation, 

Inner Magnetospheric Constellation). Highly 

focused missions require improved measurement resolution and sensitivity (MMS, GEC, 

RAM, MTRAP, GEMINI, DOPPLER). Missions 

with special orbital requirements will need new 

kinds of in-space propulsion. Examples include requirements to dwell at a point farther 

upstream in the solar wind from the L1 libration 

point (Heliostorm), to achieve a polar heliocentric orbit (Solar Polar Imager), or to escape 

from the solar system altogether (Interstellar 

Probe). As the missions in our roadmap are 

developed, they will require new technologies 

in instrumentation, data visualization, communication, and analysis systems. Future Heliophysics technology needs fall into several focus areas.

Propulsion and Power: A number of Heliophysics missions will study solar system plasmas from unique vantage points. Propulsion 

systems that can supply a larger delta-V than 

conventional rocket engines, or that can provide large delta-V without a large mass or power 

penalty, can enable such challenging missions. 

For high-performance, cost-effective propulsion in the inner solar system, or for exiting the 

solar system in timely fashion, solar sails are 

the ideal choice. Signifi cant ground demonstrations of solar sail technologies have been 

performed already. We encourage continued 

development of this technology and support 

the idea of a fl ight demonstration during Phase 

1 of this Roadmap (CY 2005 – 2015). We also 

encourage renewed capacity to produce RTGs 

that have low-electromagnetic interference and 

high-effi ciency power conversion.

Micro-spacecraft: Owing to the large scale 

and complexity of solar system plasmas, future discoveries will depend on deployment of 

spacecraft in clusters and constellations, making simultaneous multi-point measurements 

within the plasmas under study. Enabling technologies will include low mass/power/volume 

instruments, and low-mass, low-cost spacecraft.

DSN: NASA’s Deep Space Network (DSN) 

is evolving to meet the communication and 

navigation needs of the agency’s increasingly 

complex, data-intensive missions. Analysis 

of Heliophysics Roadmap missions suggests 

that, over the next 25 years, downlink rates will 

need to increase by a factor of at least 1,000, 

even from the more distant regions of our solar system. The trend toward multi-spacecraft 

missions will likely cause a large increase in 

the number of required supportable links back 

to Earth. Near-Earth missions should use and 

cultivate the continued evolution of commercial space networks.

Advanced Computing: Advanced supercomputing is a vital capability for enabling 

space weather model development and innovative data analysis and visualization. Examples of successful innovation in this area 

include Project Columbia and the VisBARD 

project.

Instrumentation: Many future Heliophysics missions will require development of new 

scientifi c instrumentation, including large focal plane arrays, large-scale adaptive optics, 

and solar-blind energetic particle and photon 

detectors. The development of hyperspectral 

and three-dimensional detectors are needed 

for solar and geospace remote sensing. Miniaturization of high voltage power supplies will 

relieve mass and volume resource constraints. 

Increased quantum effi ciency of UV and EUV 

detectors will enable signifi cant savings in 

mass as small but sensitive instruments can be 

developed. The shear strength and impressive 

electronic properties of carbon nanotubes may 

lead to the development of stronger, lighter materials and power effi cient ionization sources. 

Conductive polymers and other exotic materials and coatings may lead to development of 

solar blind detectors, new and better dust analyzers, and miniature mass spectrometers. It is 

important to develop and maintain ground test 
123

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

facilities for simulating particle and radiation 

environments in space. Radiation test facilities 

will be particularly important as technological innovations and the push to develop more 

power effi cient instruments results in smaller 

electronic instrumentation. Ground testing is 

extremely valuable, but NASA’s low-cost access to space (LCAS) program is required for 

complete testing and full validation of advanced 

instrumentation. Imaging is an area of instrumentation where we should place signifi cant 

development effort. Remote imaging provides 

more information than any practical number of 

single-point measurements. Imaging is crucial 

to understanding the complex interacting set 

of systems that control the Sun-Solar System 

connection well enough to develop the properly constrained and accurate predictive models 

that are critical to support exploration, including a sustained human presence in space. The 

three primary imaging tools include Energetic 

Neutral Atom (ENA), Radio Tomography, and 

Photon Imaging, Photon imaging includes xray, extreme ultraviolet (EUV), far ultraviolet 

(FUV), visible (VIS) and infrared (IR).

Space Environment Testbeds (SET): The 

LWS SET technology development project 

performs spacefl ight experiments of new approaches for mitigating the effects of the dynamic space environment that are driven by 

solar and geospace variability. Its investigations validate new hardware, methods, models, and tools, all geared toward mitigating the 

effect of the space environment on systems.
124

HELIOPHYSICS

U.S. External Partnerships and Relationships

As society becomes increasingly dependent 

on technologies that are affected by space 

weather, our vulnerabilities have become more 

obvious. The nation’s efforts to mitigate space 

weather effects have placed more urgency on 

the need to understand the Sun, heliosphere, 

geospace, and other planetary environments 

as a single connected system. External constituencies requesting and making use of new 

knowledge and data from NASA’s efforts in this 

area include the Federal Aviation Administration (FAA), the Department of Defense (DoD), 

National Oceanic and Atmospheric Administration (NOAA), the power industry, and the industry of satellite manufacturers and operators 

(See Table 6.5).

Constituencies within NASA include the Exploration Systems Directorate, the Space Operations Directorate, the Deep Space Network, 

and the various satellite operations centers.

Table 6.5. NASA and external constituencies requesting and making practical use of new knowledge and 

data from NASA’s Heliophysics program.

International Cooperation

The International Heliophysical Year

(ihy2007.org): The U.S. House of Representatives Science Committee approved House 

Con. Resolution 189: Celebrating the 50th anniversary of the International Geophysical Year 

(IGY) and supporting an International Geophysical Year-2 (IGY-2) in 2007-08. The resolution calls for a worldwide program of activities 

to commemorate the 50th anniversary of the 

most successful global scientifi c endeavor in 

human history - the International Geophysical 

Year (IGY) of 1957-58. The resolution also calls 

for an “IGY-2” that would be even more extensive in its global reach and more comprehensive in its research and applications.

International Living with a Star: In January 2002, the Interagency Consultative Group 

(IACG) established the International Living 

With a Star (ILWS) program. The IACG consists of the heads of the space science programs of the European Space Agency (ESA), 

the Japan Aerospace Exploration Agency 

Advancing U.S. Scientifi c, Security, and Economic Interests
125

THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

(JAXA), the National Aeronautics and Space 

Administration (NASA), and the Russian Aviation and Space Agency (RASA). The charter 

for ILWS is to “stimulate, strengthen, and coordinate space research to understand the 

Solar Heliospheric Observatory (SOHO) Partnership with ESA

Geotail Partnership with Japan/JAXA

Cluster Partnership with ESA

Ulysses Partnership with ESA

Currently Operating Heliophysics Missions with signifi cant International participation:

Heliophysics Missions in Development with signifi cant International participation:

Solar-B Partnership with Japan/JAXA, ISAS, PPARC

STEREO Contributions from CNES, Switzerland, DLR, PPARC, ESA, Hungary

THEMIS Contributions from Canada, CNES, DLR, and Austria

MMS Contributions from recently-selected international partners

AIM Agreement with British Antarctic Survey, Australia

TWINS Contributions from DLR

Near-term Mission Concepts:

Solar Orbiter Possible partnership with ESA

LWS/ Geospace Possible contributions from to-be-selected international partners

LWS/Sentinels Possible contributions from to-be-selected international partners

governing processes of the connected SunEarth System as an integrated entity”. More 

than 20 contributing organizations are listed at

http://ilws.gsfc.nasa.gov.
126

HELIOPHYSICS

Scientists and engineers working on Heliophysics science have overcome many of the 

problems of building, fl ying, and operating 

space missions. But our science is affected by 

factors beyond the control of the community. 

Each is founded on rational decisions made 

by groups in the larger society within which we 

work. Like St. Francis, we need “the serenity 

to accept the things [we] cannot change, the 

courage to change the things [we] can, and the 

wisdom to know the difference.”

Space Launch Cost in the Free Market

 The single largest cost in most space missions is the launch vehicle. Unlike other technologies, the cost to orbit a kilogram has remained nearly constant over the past decade. 

Why is the cost so high? Space launchers are 

the most diffi cult challenges in engineering and 

manufacture because the forces and energies 

present in a launch vehicle are so great that 

they preclude graceful failures. From 1988 to 

1999, 4% of launches failed in ways that required their destruction to insure public safety. As an Aeronautics and Space Engineering 

Board report states “Destruct commands are 

often superfl uous because vehicles explode or 

break up because of dynamic forces.” In the 

early years of spacefl ight, NASA solved this 

problem by building duplicate satellites, so that 

one might succeed if another failed. Today the 

response of the users has been to emphasize 

reliability of a small number of satellites.

The commercial space market provides 

about half of the global demand for launch vehicles. The 2004 FAA/COMSTAC forecast of 

commercial demand indicates that the launch 

rate will remain static at ~22 per year from 

2000 until 2013. The principal change has 

been the demand for very large satellites, with 

the average mass per satellite growing from 

2,400 kg in 1993-94 to 4,100 kg in 2003-04. 

The recent development of EELVs by the DoD 

suggests that their needs are similar to those 

of the commercial market. Some of the other 

federal space activities, including NASA, also 

need large spacecraft and launchers. Taken 

together, the manufacturers of space launchers 

have good reason to focus on larger vehicles. 

The constant, limited numbers of launches prevents economies of scale. To recoup the high 

development costs of new launchers, it is desirable to stop the production of older, smaller 

vehicles. Opportunity for small, simple, inexpensive, or risky payloads is absent when only 

large, expensive vehicles are available. Only 

large, expensive spacecraft make commercial 

economic sense.

Yet, many NASA science missions can be 

accomplished with much smaller, less costly 

spacecraft. The SMEX, MIDEX, Discovery, 

ESSP, and New Millennium mission lines are 

all highly productive and depend on smaller 

vehicles or would benefi t from sharing launch 

opportunities.

Public Trust and Risk Tolerance

NASA provides the visible demonstration of 

the value of American technological society to 

solving grand problems. The inspiration provided by a great success such as the Mars 

Rovers is matched by the disappointment and 

concern attached to failures of other missions. 

Success and failure are visible and owned by 

the American public.

Personal freedom is one foundation of American society. We accord individuals the right 

to pursue activities that have signifi cant risk 

of failure, even injury or death, as a price of 

that freedom. These private risks, taken voluntarily, are accepted. Risk in systems supported or controlled by tax funds is not well 

tolerated. Public safety and fi scal responsibility require detailed investigation to determine 

causality and future improvement. Examples 

include airline or other controlled transportation accidents, military accidents, and NASA 

accidents.

NASA missions are growing in size, cost, and 

complexity. Growing complexity drives a compounding of levels of risk management, including detailed process control, frequent reviews, 

and greater requirements on project management. Risk management seeks to minimize 

avoidable failures, which imposes delay and 

External Drivers of the NASA Heliophysics Program
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unplanned costs on all missions because they 

share common technologies independent of 

their science focus. As with other complex aspects of our society, the cost of risk management is an increasing fraction of the total.

Yet, risk is a critical part of the process of 

learning to succeed. NASA fosters future success by offering broad range of projects and 

missions to permit new generations to learn 

through trial and error, and help the best progress to larger projects. The desire to minimize 

risk must be tempered by a desire to maximize 

long-term success.

National Security

Space technology provides unique contributions to national security, in reconnaissance, 

navigation, and communication - and space 

weather effects on such systems. American 

technological advantages over competitors 

and potential adversaries drives restrictions on 

civilian space interactions with foreign collaborators. Recent increases and uncertainties in 

these restrictions, founded in the International 

Traffi c in Arms Regulations (ITAR) and Export 

Administration Regulations (EAR), apply even 

to scientifi c interactions with friendly nations. 

To the nation’s benefi t, NASA has accorded 

Principal Investigators (PI) freedom to involve 

foreign collaborators. The total cost of these 

positive foreign interactions is increasing in 

order to insure the required compliance with 

ITAR/EAR restrictions. One result is decreased 

opportunities for the cost-sharing of space 

missions.

Yet, foreign contributions, such as the Huygens lander on the Cassini mission or the joint 

development of the SOHO mission, have immeasurably improved the quality of many science missions. Solar Probe and ESA’s Solar 

Orbiter may provide similar opportunities as 

part of the International Living With a Star program. Strengthening the technical teamwork 

between the U.S. and our partners permits activities that could not be achieved separately.

NASA and External Factors

These problems are opportunities for NASA 

leadership. Fiscal responsibility and scientific and technological opportunities are strong 

arguments for working to maintain a range of 

launch vehicles, both large and small. This is a 

capability important to NASA.

The public and future scientists are inspired 

by spacefl ight because it challenges us to advance the limits of our abilities. Engaging the 

public in the challenges and inherent risks of 

pioneering spacefl ight and exploration is an 

opportunity for E/PO on these issues in modern systems. NASA’s work with its communities to develop the most cost-effi cient methods 

for appropriate risk management of complex 

space projects is a capability that can improve 

many areas of our technical society and economy.

Foreign collaborations add value that advances America’s space goals. Aiding its projects to achieve cost-effective compliance with 

ITAR rules is a capability important to NASA. 

Continued dialog and negotiation between 

NASA and the other relevant agencies to develop and clarify more appropriate rules for 

space research missions will enhance the capability of those agencies for dealing with other 

critical technical issues.
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Appendices 
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Appendix A. 2005 Heliophysics Roadmap Teams

Chairs and Coordinators

J. Todd Hoeksema - Stanford University

Thomas Moore - NASA Goddard Space Flight 

 Center

Al Diaz - NASA Headquarters

Timothy Killeen - National Center for 

 Atmospheric Research

Franco Einaudi - NASA Goddard Space Flight 

 Center

Barbara Giles - NASA Headquarters

Azita Valinia - NASA Goddard Space Flight 

 Center

Committee Members

Markus Aschwanden - Lockheed-Martin

Scott Bailey - University of Alaska

Thomas Bogdan - National Center for 

 Atmospheric Research

Cynthia Cattell - University of Minnesota

Scott Denning - Colorado State University

Gregory Earle - University of Texas at Dallas 

Joseph Fennell - Aerospace Corporation

Jeffrey Forbes - University of Colorado

Stephen Fuselier - Lockheed-Martin

Glynn Germany - University of Alabama, 

 Huntsville 

William Gibson - Southwest Research Institute

Nat Gopalswamy - NASA Goddard Space 

 Flight Center

Don Hassler - Southwest Research Institute

Rosamond Kinzler - American Museum of 

 Natural History

Craig Kletzing - University of Iowa

Barry LaBonte - JHU Applied Physics Lab

Michael Liemohn - University of Michigan 

Paulett Liewer - NASA Jet Propulsion Lab

Edward Lu - NASA Johnson Space Center

Neil Murphy - NASA Jet Propulsion Lab

Victor Pizzo - National Oceanic and 

 Atmospheric Administration

Edmond Roelof - JHU Applied Physics Lab

James Russell - Hampton University

James Slavin - NASA Goddard Space Flight 

 Center

Leonard Strachan - Smithsonian Astro- 

 physical Observatory

Michelle Thomsen - Los Alamos National Lab

Ex Offi cio Members

Donald Anderson - NASA Headquarters

Richard Fisher - NASA Headquarters

Mark Weyland - NASA Johnson Space Center

Michael Wargo - NASA Headquarters

Al Shafer - Offi ce of the Secretary of Defense

Mission Study Engineers and

Science Support

Juan Ayon - NASA Jet Propulsion Lab

John Azzolini - NASA Goddard Space Flight 

 Center

Michael Calabrese - NASA Goddard Space 

 Flight Center

Mary DiJoseph - NASA Goddard Space Flight 

 Center

Parminder Ghuman - NASA Goddard Space 

 Flight Center

Craig Pollock - NASA Headquarters

Jennifer Rumburg - NASA Goddard Space 

 Flight Center

James Spann - NASA Marshall Space Flight 

 Center

Chris St. Cyr - NASA Goddard Space Flight 

 Center

J. Timothy Van Sant - NASA Goddard Space 

 Flight Center
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The Heliophysics community mourns the death of our colleague, Dr. Barry 

LaBonte. He contributed in many ways to this Roadmap for our nation’s 

future - as a team member, as a long-time leader of Sun-Earth Connection 

science, and as an innovative solar observer. Barry’s wisdom helped us see 

more clearly, think more deeply, and communicate more effectively. His incisive humor and global views brought us together. His intellectual integrity 

and intolerance for fuzzy thinking helped us remain true. Barry’s enthusiasm 

for science, education, and exploration was infectious and his dedication to 

plain speaking was inspiring. We will miss Barry LaBonte.
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Key Agency Documents

A Journey to Inspire, Innovate, and Discover, June 2004 (the Aldridge Commission Report). 

The Need to Transform the Structure and Management of NASA, Report of the Roles, Responsibilities And Structures (“Clarity”) Team, June 24, 2004.

A Renewed Commitment to Excellence: An Assessment of the NASA Agency-wide Applicability of the Columbia Accident Investigation Board Report, January 30, 2004 (the Diaz Report).

The Columbia Accident Investigation Board Report, 2003 (the CAIB report)

Space Science Enterprise Strategy, October 1, 2003.

Sun-Earth Connection Roadmap, 2003-2028, January 2003.

Enhancing Mission Success -- A Framework for the Future, A Report by the NASA Chief Engineer and the NASA Integrated Action Team, January 2001.

NRC Bibliography (Past 5 Years)

 Science in NASA’s Vision for Space Exploration, Space Studies Board, National Research 

Council, 2005, ISBN 0-309-09593-X

Plasma Physics of the Local Cosmos, Committee on Solar and Space Physics, National Research Council, 2004, ISBN 0-309-09215-9

Solar and Space Physics and Its Role in Space Exploration, Committee on the Assessment 

of the Role of Solar and Space Physics in NASA’s Space Exploration Initiative, Space Studies 

Board, National Research Council, 2004, ISBN 0-309-09325-2.

Steps to Facilitate Principal-Investigator-Led Earth Science Missions, Committee on Earth 

Studies, National Research Council, 2004, ISBN 0-309-09185-3.

Issues and Opportunities Regarding the U.S. Space Program, Summary report of a workshop 

on National Space Policy, National Research Council, 2004.

The Sun to the Earth -- and Beyond: Panel Reports, Solar and Space Physics Survey Committee, Committee on Solar and Space Physics, National Research Council, 2003, ISBN 0-309-

08972-7

Assessment of NASA’s Draft 2003 Space Science Enterprise Strategy, a letter report, May 29, 

2003

Assessment of NASA’s Draft 2003 Earth Science Enterprise Strategy, a letter report, July 31, 

2003

Assessment of Mars Science and Mission Priorities, Committee on Planetary and Lunar Exploration, 2003, ISBN 0-309-08917-4.

The Sun to the Earth -- and Beyond: A Decadal Research Strategy in Solar and Space Physics, 

Solar and Space Physics Survey Committee, National Research Council, ISBN 0-309-08509-8

Review of NASA’s Earth Science Enterprise Applications Program Plan, Task group report, 

2002

Assessment of the Usefulness and Availability of NASA’s Earth and Space Science Mission 

Data, task group report, 2002.

Assessment of Mars Science and Mission Priorities, Committee on Planetary and Lunar Exploration, 2001, ISBN 0-309-08917-4.

Appendix B. Bibliography of Key Agency and NRC Documents
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THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

NRC Bibliography (Past 5 Years) - continued

Interim Assessment of Research and Data Analysis in NASA’s Offi ce of Space Science: Letter 

Report, Committee on Solar and Space Physics, Committee on Planetary and Lunar Exploration, 

Committee on Astronomy and Astrophysics, Space Studies Board National Research Council, 

Letter report, 2000.

Assessment of Mission Size Trade-offs for NASA’s Earth and Space Science Missions, Space 

Studies Board Ad Hoc Committee on the Assessment of Mission Size Trade-Offs for Earth and 

Space Science Missions, Space Studies Board, National Research Council, 2000, ISBN 0-309-

06976-9.

The Role of Small Satellites in NASA and NOAA Earth Observation Programs, SSB, 2000

Radiation and the International Space Station: Recommendations to Reduce Risk, Committee 

on Solar and Space Physics and Committee on Solar-Terrestrial Research, National Research 

Council, 2000, ISBN 0-309-06885-1.
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Recognizing that a ‘business as usual’ approach was not likely to be effective, this Roadmap has taken a different approach to prioritizing the Heliophysics strategy. Beginning 

with the NASA strategic objective assigned to 

the new Heliophysics division, the Roadmap 

Committees performed a complete requirements-driven derivation of a program to meet 

the nation’s needs. The committee was supplied by the reports developed by the NRC, including the Decadal Survey and the update to 

that survey. The committee was also informed 

by community input in form of formal reports, 

white papers, through a community workshop, 

and through personal contacts. 

The three top Heliophysics objectives were 

broken down into research focus areas that 

support the achievement of the top-level goal. 

The focus areas in turn led to two somewhat independent, more detailed breakdowns of effort 

– investigations and targeted outcomes. This 

contrasts with past efforts that have been constructed essentially from the bottom up based 

primarily on scientifi c priorities and opportunities as well as the perceived needs of the users 

of Heliophysics science.

The investigations present the more familiar 

scientifi c approach to organizing the efforts, 

one that lays out a logical progression toward 

addressing the broad topics outlined in the 

research focus areas. The investigations are 

enumerated in Chapter 2 with the descriptions 

of the research focus areas for each objective. With each investigation it was relatively 

straightforward to identify missions and supporting elements of the program required to 

make real progress. Setting priorities was 

more diffi cult.

 The targeted outcomes shown in Chapter 3 

provide an alternate basis for constructing a 

program; one that the Roadmap Committees 

found helpful for assigning priority to various 

components of the program. We identifi ed for 

each research focus area the achievements 

that should be completed during each of the 

next three decades. The achievements are 

shown in Table 3.2 (Pg. 58) of Chapter 3. Each 

achievement was developed and expanded in 

a fl ow-down chart listing fi rst the required understanding, then the enabling capabilities and 

measurements, and fi nally the implementation 

linked to missions and other supporting proAppendix C. 

Reconciling the Roadmap and Decadal Survey Approaches & Results

Table C.1
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gram elements. One sample chart is shown in 

the accompanying fi gure.

The timing of the achievements was driven 

fi rst of all by what is required to support the 

new Vision for Space Exploration with which 

NASA has been tasked. With an ambitious, 

though not fully developed, schedule for returning humans to the Moon for an extended 

period followed by human mission to Mars, 

certain information is critical for defi ning and 

designing a safe and productive exploration 

program. NASA’s Heliophysics Division science contributes crucial information to inform 

and enable that phased effort and we have ordered our programs to provide the necessary 

information at the appropriate time. Of course 

exploration is more than human spacefl ight 

and the program emphasizes robotic exploration in pursuit of transformational knowledge 

as well.

Second, the scientifi c development of the 

program requires a logical progression of discovery, understanding and prediction. While 

these go hand-in-hand and different parts of 

the program are in different stages, this criterion is similar to the drivers used to formulate 

our strategic plans in the past. The difference 

this time is that the scheduling is driven by 

more than just the simple desire to pick the 

questions that show the greatest promise for 

progress. This time we were looking for progress in particular areas.

Our fi nal criterion was to defi ne a program 

that is possible to achieve – both technically 

and fi nancially. This was a real challenge with 

the reduced funding available in both the Explorer and STP programs. Many important 

topics are deferred, put aside, or left for implementation in the Explorer program. The optimized plan restores many synergies lost in the 

plan based on projections of the current budget.

How did the resulting program compare 

to earlier recommendations provided in the 

decadal survey and previous SEC Roadmaps 

and NASA Enterprise Strategy?

The NRC and roadmap committees ended 

up in remarkably similar places. The science 

and exploration objectives, the research focus areas, investigations, and achievements 

match very well. There is a somewhat broader 

scope in this roadmap because of the connections with Earth science, the new emphasis on 

the journey of exploration, and the longer time 

period considered. The missions proposed 

include all the top priorities of the 2002 NRC 

Report: The Sun to the Earth - and Beyond for 

NASA. Together with the completion of STEREO, Solar-B, and SDO and the continued operation of the Heliophysics Great Observatory, 

these include Solar Probe, MMS, RBSP & ITSP, 

JPO/Juno, IH Sentinels, GEC, LCAS, MMS, L1/

Heliostorm, GEMINI, L1 Monitor, Solar Orbiter, 

Explorers, and all of the relevant recommendations for vitality as well. (A few mission names 

have changed). Table C.2 gives a detailed 

comparison between the 2002 Decadal Survey 

Science Challenges and the Research Focus 

Areas described in Chapter 2.

How can this be? 1) The basic science 

needed to predict conditions for safe and productive exploration is much the same understanding required to handle the affects of the 

space environment on society. The requirements for the journey of exploration have been 

largely anticipated by LWS. 2) The strategy 

laid out in the past was robust, in the sense 

that the long-term objectives transcend most 

immediate changes in emphasis. Understanding of the entire system was crucial and remains crucial. The science questions and the 

order in which they must be addressed remain 

much the same in order to open the frontier to 

space weather prediction. The STP missions 

of necessity fl y at a slower rate, but the basic 

science they will provide serves the most important needs of the NASA vision. 3) With 

reduced resources the missions already initiated will take the remainder of the decade to 

complete. In our scenario based on current 

projections no mission will launch before 2015 

that has not already begun and this time frame 

goes beyond the end of the decadal survey. 

Because these missions support the vision, the 

program looks very much the same in the near 

term as it did three years ago.

There are some important changes to the intermediate and long term program. The importance of the inner heliosphere through which 

disturbances propagate has increased. New 

missions to understand energetic particles 
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HELIOPHYSICS

have been identifi ed and we have recommended increased collaboration with Earth science 

colleagues to understand the terrestrial radiation budget. There is also increased emphasis 

on the contributions our discipline can make 

to understanding the Martian atmosphere and 

the role space weather effects have on planetary habitability. Decision points have been 

set where choices need to be made about the 

direction of the program based on evolving priorities and what is learned in the mean time. 

As in previous Roadmaps, a suite of unfunded 

fl agship and partnership missions has been 

identifi ed to address problems that cannot 

be handled in the existing mission lines; however, some of the partnership missions have 

changed. The importance of L1 observations 

has increased. And, unfortunately, many of the 

intermediate term missions from the last Roadmap have been pushed farther into the future.

Table C.2
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• Auroral Acceleration Multi-Probes (AAMP)

• Aeronomy of Ice in the Mesosphere (AIM)

• Aeronomy and Dynamics at Mars (ADAM)

• Bepi-Colombo (BC)

• Coupled Ion-Neutral Dynamics Investigation (CINDI)

• Dayside Boundary Constellation (DBC)

• Doppler

• Farside Sentinel (FS)

• Geospace Electrodynamic Connections (GEC)

• Geospace Magnetospheric and Ionospheric Neutral Imager (GEMINI)

• Geospace System Response Imager (GSRI)

• Heliospheric Imager and Galactic Observer (HIGO)

• Heliostorm

• Interstellar Boundary Explorer (IBEX)

• Inner Heliospheric Sentinels (IH Sentinels)

• Inner Magnetospheric Constellation (IMC)

• Interstellar Probe (ISP)

• Io Electrodynamics

• Ionosphere Thermosphere Mesosphere (ITM) Waves

• Ionosphere-Thermosphere Storm Probes (ITSP)

• Janus

• Jupiter Polar Orbiter/Juno

• L1 Diamond

• L1 Earth-Sun

• L1 Mars

D. Heliophysics Mission Studies

Numerous missions of signifi cant interest to the Heliophysics community have been proposed 

during the course of the Roadmap process. Each one is presented briefl y in this Appendix in a 

half-page Quad Chart. Each Quad Chart covers the four main elements of a mission: it lists the 

major scientifi c objectives, describes the mission concept, outlines the measurement strategy, 

and identifi es technology enablers and enhancers; a signature graphic is usually included as well. 

The charts are presented for informational purposes and have been only lightly edited.

This appendix includes the top priority strategic missions identifi ed in the 2005 Roadmap. 

Additional missions are also included in order to document current community ideas along with 

missions identifi ed in previous roadmaps that were actively discussed, but not included in the 

2005 Roadmap narrative.

The level of study maturity varies, as detailed on page 140. Some missions exist only as a quad 

chart concept and description. Others have undergone some level of engineering concept or 

Vision Mission study or been proposed as Explorers. Some missions are already in pre-formulation or have been the subject of extensive science defi nition team effort. This Appendix includes 

the Heliophysics Explorer, STP, and LWS missions currently in formulation and implementation in 

order to connect the existing program’s science objectives and achievements with the missions 

described in this Roadmap.

The evolution of mission priorities derived from the NASA Strategic Planning and Budget process drives the direction and pace of additional studies for selected missions to raise their study 

maturity level in support of this process.

Alphabetical Listing of Quad Chart Summaries
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• L1-Sentinel

• L1 Solar-Climate Connection Explorer

• Lunar Reconnaissance Orbiter (LRO)

• Lunar Imaging Radio Array (LIRA)

• Magnetic TRAnsition region Probe (MTRAP)

• Mars Atmospheric Reconnaissance Survey (MARS)

• Mars Science Laboratory (MSL)

• Magnetosphere-Ionosphere Observatory (MIO)

• Magnetospheric Constellation (MC or MagCon)

• Magnetospheric Multiscale (MMS)

• Mars Dynamics

• Mars GOES

• Near Earth Solar Coronal Explorer (NESCE)

• Neptune Orbiter

• New Horizons - Pluto Kuiper Belt Mission 

• Radiation Belt Storm Probes (RBSP)

• Reconnection and Microscale Probe (RAM)

• Solar-B

• Solar Connection Observatory for Planetary Environments (SCOPE)

• Solar Dynamics Observatory (SDO)

• Solar Energetic Particle Mission (SEPM)

• Solar Heliospheric & Interplanetary Environment Lookout for Deep Space (SHIELDS)

• Solar Imaging Radio Array (SIRA)

• Solar Orbiter (SO)

• Solar Polar Imager (SPI)

• Solar Probe (SP)

• Solar Sail Demo (SSD)

• Solar-TERrestrial RElations Observatory (STEREO)

• Solar Weather Buoys (SWB)

• Space Environment Testbeds (SET)

• Space Physics Package and Interface

• ST-5 Microsat Technology Constellation Validation 

• Stellar Imager (SI)

• Sun-Earth Coupling by Energetic Particles (SECEP)

• Sun-Earth Energy Connector (SEEC)

• Telemachus

• Time History of Events and Macroscale Interactions During Substorms (THEMIS)

• Titan

• Two Wide-Angle Imaging Neutral-Atom Spectrometeres (TWINS)

• Tropical ITM Coupler (ITMC)

• Venus Aeronomy Probe

• Whole Sun Sentinels
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E. Acronyms

AAAS American Association for the Advancement of Science

AAMP Auroral Acceleration Multi-Probe

ACE Advanced Composition Explorer

ADAM Aeronomy and Dynamics at Mars

AIM Aeronomy of Ice in the Mesosphere 

AISR Applied Information Systems Research

AMISR Advanced Modular Incoherent Scatter Radar 

APIO Advanced Planning and Integration Offi ce 

ATST Advanced Technology Solar Telescope

AU Astronomical Unit

BC Bepi-Colombo

C/NOFS Communication/Navigation Outage Forecast System satellite

CAIB Columbia Accident Investigation Board

CCD Charge-Coupled Device

CCMC Coordinated Community Modeling Center

CEDAR Coupling, Energetics and Dynamics of Atmospheric Regions

CINDI Coupled Ion-Neutral Dynamics Investigation 

CIRB Cosmic Infrared Background

CISM Center for Integrated Space-Weather Modeling

CME Coronal Mass Ejection

CNES Centre National d’Etudes Spatiales

COMSTAC Commercial Space Transportation Advisory Committee 

CSEM Center for Space Environment Modeling

CULPRIT CMOS Ultra Low-Power Radiation Tolerant

CY Calendar Year

DASI Distributed Arrays of Small Instruments

DBC Dayside Boundary Constellation

DLR Deutschen Zentrum fÜr Luft und Raumfahrt

DSN Deep Space Network

DoD Department of Defense

DoE Department of Energy

E/PO Education and Public Outreach

EAR Export Administration Regulations 

EDL Entry, Descent, and Landing

EELV Evolved Expendable Launch Vehicle

EIT Extreme-ultraviolet Imaging Telescope

ENA Energetic Neutral Atom

E/PO Education and Public Outreach
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EPP Energetic Particle Precipitation

ESA European Space Agency

ESF Equatorial Spread-F 

ESSP Earth System Science Pathfi nder

EUV Extreme Ultraviolet

EVA Extravehicular Activities

EXP Explorer Missions 

EXT Externally Funded Partnership Missions 

FAA Federal Aviation Administration 

FASR Frequency Agile Solar Radiotelescope

FAST Fast Auroral Snapshot

FLG Flagship Missions

FS Farside Sentinel

FUV Far Ultraviolet

FiMS Fellowships in Mathematics and Science

GCR Galactic Cosmic Ray

GEC Geospace Electrodynamic Connections

GEM Geospace Environment Modeling

GEMINI Geospace Magnetosphere-Ionosphere Neutral Imagers

GI Guest Investigator

GOES Geostationary Operational Environmental Satellite

GPS Global Positioning System

GSFC Goddard Space Flight Center

GSRI Geospace System Response Imager

GSP Geospace Storm Probes – GSRI, ITSP and RBSP

GeV Giga Electron Volt

HIGO Heliospheric Imager and Galactic Observer

HS Heliostorm

IACG Interagency Consultative Group

IBEX Interstellar Boundary Explorer 

IE Io Electrodynamics 

IGY International Geophysical Year

IH Sentinels Inner Heliospheric Sentinels

IHS Inner Heliospheric Sentinels

ILWS International Living With a Star

IMAGE Imager for Magnetosphere-to-Aurora Global Exploration mission

IMC Inner Magnetospheric Constellation

IMF Interplanetary Magnetic Field

INSPIRE Interactive NASA Space Physics Ionosphere Radio Experiments

IR Infrared
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ISAS Institute of Space and Astronautical Sciences

ISP Interstellar Probe

ISS International Space Station

I-T Ionosphere-Thermosphere

ITAR International Traffi c in Arms Regulations

ITM Ionosphere Thermosphere Mesophere

ITMC Tropical ITM Coupler

ITMC/W Tropical ITM Coupler/Waves

ITMW Ionosphere Thermosphere Mesosphere Waves

ITSP Ionosphere Thermosphere Storm Probes

IVM Ion Velocity Meter

ISP Interstellar Probe

JAXA Japan Aerospace Exploration Agency

JHU Johns Hopkins University

JPL Jet Propulsion Laboratory

JPO Jupiter Polar Orbiter/JUNO

JRO Jicamarca Radio Observatory

keV Kilo Electron Volt

L1 SCE L1 Solar Climate Connection Explorer

L1D L1-Diamond

LASCO Large Angle and Spectrometric Coronagraph

LCAS Low Cost Access to Space

LIRA Lunar Imaging Radio Array

LISM Local Interstellar Medium

LPE Low-Power Electronics

LRO Lunar Reconnaissance Orbiter 

LWS Living With a Star

MA Mars Aeronomy 

MagCon Magnetospheric Constellation

MARIE Mars Radiation Environment Experiment

MARS Mars Atmospheric Reconnaissance Survey 

MC Magnetospheric Constellation 

MD Mars Dynamics 

MDI Michelson Doppler Imager

MEMS Micro-Electro-Mechanical Systems

MeV Mega Electron Volt

MGS Mars Global Surveyor

MHD Magnetohydrodynamics

MIDEX Medium-class Explorer

MIO Magnetosphere-Ionosphere Observatory 
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MIT Magnetosphere, Ionosphere, and Thermosphere 

MMS Magnetospheric Multiscale Mission

MO&DA Mission Operations and Data Analysis

MOO Mission of Opportunity

MSL Mars Science Laboratory

MTRAP Magnetic Transition Region Probe

NASA National Aeronautics and Space Administration

NESCE Near Earth Solar Coronal Explorer

NH New Horizons - Pluto/Kuiper Belt Mission 

NO Neptune Orbiter 

NOAA National Oceanic and Atmospheric Administration

NRC National Research Council

NSF National Science Foundation

NWM Neutral Wind Meter

PA Public Affairs 

PASO Particle Acceleration Solar Orbiter

PEPPSI Pluto Energetic Particle Spectrometer Science Investigation 

PI Principal Investigator

PMC Polar Mesospheric Clouds

POETRY Public Outreach, Education, Teaching and Reaching Youth

PPARC Particle Physics and Astronomy Research Council 

RAD Radiation Assessment Detector

RAM Reconnection and Microscale Probe

RASA Russian Aviation and Space Agency 

RBSP Radiation Belt Storm Probes

RE Earth Radii

REU Research Experiences for Undergraduates

RFA Research Focus Area

RHESSI Reuven Ramaty High Energy Solar Spectroscopic Imager 

RTG Radioisotope Thermoelectric Generator

SAMPEX Solar Anomalous and Magnetospheric Particle Explorer

SCOPE Solar Connection Observatory for Planetary Environments 

SDO Solar Dynamics Observatory

SEC Sun-Earth Connection

SECEF Sun-Earth Connection Education Forum

SECEP Sun Earth Coupling by Energetic Particles

SEEC Sun-Earth Energy Connector

SEP Solar Energetic Particle

SEPM Solar Energetic Particle Mission

SET Space Environment Testbeds

SHECon Sun-Heliosphere-Earth Constellation
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THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION 

SHIELDS Solar Heliospheric & Interplanetary Environment Lookout for Deep Space 

SHINE Solar, Heliosphere and Interplanetary Environment

SI Stellar Imager

SIRA Solar Imaging Radio Array

SMD Science Mission Directorate

SMEX Small Explorer

SO Solar Orbiter

SOHO Solar and Heliospheric Observatory

SON Student Observing Network

SP Solar Probe 

SPI Solar Polar Imager

SPP Space Physics Package 

SR&T Supporting Research and Technology

SSB Space Studies Board

SSD Solar Sail Demo

ST-5 Space Technology 5

ST-9 Space Technology 9

STDT Science and Technology Defi nition Team 

STEM Science, Technology, Engineering and Mathematics

STEREO Solar-Terrestrial Relations Observatory

STP Solar-Terrestrial Probe

SWAP Solar Wind Around Pluto

SWB Solar Weather Buoys

TE Titan Explorer 

THEMIS Time History of Events and Macroscale Interactions during Substorms

TIMED Thermosphere Ionosphere Mesosphere Energetics and Dynamics

TLM Telemachus 

TR&T Targeted Research and Technology

TRACE Transition Region and Coronal Explorer

TRL Technology Readiness Level

TWINS Two Wide-angle Imaging Neutral-atom Spectrometers

UAF Univ. of Alaska, Fairbanks

UV Ultraviolet

VAP Venus Aeronomy Probe 

VIS Visible

VSE Vision for Space Exploration 

VXO Virtual Observatories

ViSBARD Visual System for Browsing, Analysis, and Retrieval of Data

WSS Whole Sun Sentinels 

XML Extensible Markup Language

XUV Extreme Ultraviolet
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HELIOPHYSICS
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THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION