The Quarterly Publication of the NASA 

Advanced Supercomputing Division

NAS researchers are developing a software 

component for mesh and field data known as

Field Model to enable the sharing of data from a

variety of scientific disciplines. See page 9

Solving The Cancer Equation — 4

The Heat Is On . . . Earth — 6

Special Section: NASA at SC2001 — 1A

Air Traffic Control Using Wake Vortex Management — 14

Field Model: Developing A Scientific Data Model — 9

Fall 2001
Vol. 2, No. 3 • Fall 2001

Executive Editors: Bill Feiereisen

John Ziebarth

Editor: Nicholas A. Veronico

Writers: Holly A. Amundson

Jill A. Dunbar

Patrick Moran

Graphic Designer: Sue Kim

Illustrator: Gail Felchle

Photographer: Michael Boswell

Contact the Editor:

Nicholas A. Veronico

Gridpoints

M/S 258-6

Moffett Field, CA 94035-1000

Tel. (650) 604-3046

Fax (650) 604-4377

nveronico@mail.arc.nasa.gov

Gridpoints is a quarterly publication of the NAS

Advanced Supercomputing Division at NASA

Ames Research Center. The division’s staff includes

government employees and contractors from

Advanced Management Technology Inc., Computer Sciences Corp., Cray Inc., Eloret, Raytheon Co.,

and SGI.

Gridpoints acknowledges that some words, model

names and designations mentioned herein are the

property of the trademark holder. Gridpoints uses

them for identification purposes only.

The staff of Gridpoints would like to

thank the following people for their

assistance in preparing this publication:

David Alfano, Dick Anderson, Bryan

Biegel, Michael Boswell, Johnny Chang,

Jill Dunbar, Chris Gong, T.R.

Govindan, Chris Henze, Daniel Herr,

Mary Hultquist, Bill Johnston, Randy

Kaemmerer, Sue Kim, Chris Kleiber,

Tim Lee, Marco Librero, Y.K. Liu, Nagi

Mansour, Meyya Meyappan, George

Myers, Terry Nelson, Marcia Redmond,

Karim Shariff, Ryan Spaulding, Leigh

Ann Tanner, Scott Thompson, Malu

Trehan, Arsi Vaziri, Cliff Williams

On The Cover:

Subscribe to Gridpoints

Subscriptions to Gridpoints are complimentary.

Please send e-mail with your name, company

name, title, address, and zip code to:

gridpoints@nas.nasa.gov

or subscribe online at:

www.nas.nasa.gov/gridpoints/subscribeform.html

Note: Subscribers outside the continental United

States can access Gridpoints on the web in PDF

format at: http://www.nas.nasa.gov/gridpoints

The Quarterly Publication of the NASA 

Advanced Supercomputing Division 4

6

1A

14

Features

Solving The Cancer Equation

A visiting professor at the NAS Division believes the

key to winning the war against breast cancer is using

partial differential equations to model the spread of

cancer in individuals.

Holly A. Amundson

NASA At SC2001:

Demonstration Listing

Researchers from six NASA centers gather in

Denver to showcase their work in high-end

computing, networking, and visualization.

Special 12-page insert begins following Page 8. National Aeronautics and Space Administration

DENVER, CO

The Heat Is On. . . Earth

Computational Chemistry is being used to calculate the

level of toxicity of industrial compounds being released

into the Earth’s atmosphere, which are contributing to

a rise in global surface temperatures.

Holly A. Amundson MESOSPHERE

STRATOSPHERE

POSPH

Air Traffic Control Through

Wake Vortex Management

Theories advanced by the NAS Division’s

Physics Simulation and Modeling Office will

increase airport capacity by reducing aircraft

spacing in bad weather.

Nicholas A. Veronico

Field Model: Developing A

Data Model For Scientific Data

Field Model is designed to enable the sharing

of data from a variety of scientific disciplines,

as well as increase reuse of analysis and visualization software components.

Patrick J. Moran

NAS researchers have developed the Field Model for data sharing and visualization

across scientific disciplines. Volume rendering of a vitamin B-12 molecule. For more

information, turn to page 9. (Chris Henze)

9
NAS Speeds New Rocket

Turbine Design

Engineers at NASA’s Marshall Space

Flight Center (MSFC) were

recently able to shave three-and-a-half

months off the task of simulating a

supersonic turbine, thanks to the work

of NAS Division user services staff.

The simulations were performed on

supercomputers located at the NASA

Advanced Supercomputing (NAS)

Facility, to analyze the unsteady flow in

an advanced turbine design. The

results will help in the design of more

efficient and durable rocket engines.

Responding quickly to a request from

MSFC’s Applied Fluid Dynamics

Analysis Group, Chuck Niggley, NAS

Scientific Consulting Group lead, and

colleague Herbert Yeung, provided

access to special computational resources when regular resources proved

insufficient for the MSFC simulation

task. The NAS team set up a special

account for users, and worked around

the clock to keep MSFC apprised of

anticipated changes in the computing

environment.

In a letter of thanks to NASA officials,

Daniel J. Dorney, of MSFC’s Applied

Fluid Dynamics Analysis Group, said:

“Both Chuck and Herbert should be

complimented on their willingness to

help users solve computer-related issues, their understanding of users

deadlines, and their positive attitude.”

The NAS Division, in collaboration with our industry partner SGI, has installed and is now running a 1,024-processor single-system image (SSI)

supercomputer. The SSI system is unique in that it uses

a single operating system to control its 1,024-processors,

a single shared memory, and the input/output subsystem. Division researchers had high expectations for how

a number of scientific applications would scale on the new system. To date, we

have run both aero- and Earth-science applications, and our scaling expectations have proven true. In addition, the 1,024-processor supercomputer uses

the same operating system and compilers as our previous SSI machines, which

enables scientists to transition to the new computer without losing valuable

research time rewriting codes.

Bringing the 1,024 processor SSI supercomputer on line provides more powerful nodes enabling researchers to access remotely located computing resources, storage devices, and scientific instruments. NASA Administrator Dan

Goldin has supported the division’s strategy of developing a distributed computing environment, NASA’s Information Power Grid (IPG) project, and

enhancing the power of nodes on the grid. 

A number of research projects made possible through the advancements in

compute power are profiled in this issue. NAS Division computational chemists

are collaborating with academic researchers to determine the global warming

potentials of industrial compounds. This research will provide an insight into

our planet’s climate, and help determine what actions should be taken today

to safeguard our future.

In the area of biomedicine, a visiting professor of mathematics from Eastern

Illinois University is working with NAS researchers to develop mathematical

models for predicting the spread of cancer cells in the human body, and how

the cells can be contained. This research is focusing on breast cancer, a disease

that attacks both men and women.

Members of the NAS Research Branch’s Data Analysis Group, have developed

the Field Model, a tool that allows researchers from different disciplines to

share, visualize, and interact with computational data. In addition, the division’s Physics Simulation and Modeling Office has patented a new method for

reducing the spacing of aircraft on approach to landing. When adopted by

industry, this spacing method will help increase airport capacity.

NASA will be showcasing a number of the division’s research projects that

have been brought to fruition through the use of high-end computers at the

SC2001 conference in Denver, November 11-16. Our partners at five other

NASA centers will join us to demonstrate the advancements achieved through

computational science and high-speed networking. I invite you to stop by our

booth to see this work firsthand, or view a brief synopsis of each research

demonstration in the SC2001 insert following page 8.

As always, I welcome your feedback.

Bill Feiereisen

wfeiereisen@mail.arc.nasa.gov

From The Division Chief

NAS Mission

To lead the country in the research,

development, and delivery of revolutionary, high-end computing services

and technologies, such as applications

and algorithms, tools, system software,

and hardware to facilitate NASA mission success.

Gridpoints 1

Continued on page 2

News

From

NAS
MSFC has designed and experimentally tested a supersonic

turbine, called the “Simplex” turbine. This “partial-admission” turbine (that is, the flow enters the turbine over only a

portion of the turbine inlet) was designed as a ground

demonstrator, and was experimentally tested with both metal

and composite airfoils (blades) to study the feasibility and

durability of advanced composite materials. “The experiments showed that the composite airfoils performed very

well,” said Dorney.

While the experiments yielded significant insight into the

flow physics, an assessment of the unsteady flow field

required the extensive use of three-dimensional simulations.

The simulations were also intended to provide a better

understanding of the flow physics of partial-admission turbines, often used in rocket engines. According to Dorney, the

simulations were also used to validate NASA’s CORSAIR

code for partial admission and full-annulus simulations.

Although computational models normally consider only a

portion of the 360-degree annulus of the turbine, the nature

of the Simplex turbine required simulation of the full 360-

degree annulus, modeling all of the airfoils, Dorney explained. The computational grid used in the simulations contained

in excess of seven million grid points and required approximately two months of wall-clock time for each simulation.

Specific goals for these simulations were to determine the

unsteady pressures experienced by the turbine airfoils to help

interpret the experimental data and help determine the durability of the airfoils. Another goal was to determine the

effects of a partial admission flow field on the performance of

the turbine. The simulations served as precursors for many

Space Launch Initiative tasks, which consider the use of partial admission turbines.

Division Engineers Address 802.11b Wireless Security Flaws In NAS Environment

The network group and information security group in the

NAS Division have successfully installed a secure interoperable wireless network that addresses the well-known

problems of the 802.11b standard wireless systems – with a

minimum of time and investment.

“Wired equivalent privacy isn’t the equivalent of wired privacy,” said Dave Tweten, computer security official at NAS.

The network group and information security group started

with the premise that the network itself provides no reliable

authentication and no security from eavesdropping, and

decided not to depend on any security provisions bundled

with 802.11b products.

Why? Recent conference results have established that

802.11b wireless systems provide no substantial security protection in any of three important respects: The signal coverage perimeter cannot be easily limited to conform to an organization’s physical control perimeter; wireless card hardware

addresses cannot be trusted as tools to identify a user; and

Wired Equivalent Privacy (WEP) encryption of data sent

between a laptop and an access point can be cracked, regardless of key length.

In addition, said Tweten, the means to derive a WEP encryption key from eavesdropped ciphertext and a method for

decrypting WEP traffic without ever needing to derive the

key are well documented.

The NAS Division chose to secure its wireless network while

assuming that it would be accessible from areas outside the

division’s control. The team also assumed that all information on the network would be subject to eavesdropping, and

that no identification information built into 802.11b could

be trusted. “All 802.11b security features were disabled on

the grounds that they only consume resources without delivering any real security,” Tweten said.

For minimum administrative overhead, basic use of the wireless network is possible without authentication. This is possible because the services that can be reached require authentication and perform encryption themselves. At the same

time, users are protected from an attack launched on the

Internet at large.

In the NAS Division, this is accomplished by an off-the-shelf

PC running the OpenBSD operating system, an Apache web

server, the Internet Software Consortium Dynamic Host

Configuration Protocol server, and the IPF (Internet Packet

Filter) firewall software – all freeware. Network and security

team members Nichole Boscia and Derek Shaw developed

the “glue” software to make the rest of the components work

together – in about 40 hours. For a copy of the Wireless Firewall Gateway White Paper, visit: www.nas.nasa.gov/ Research/

Tasks/Networks/Wireless/ whitepaper.html

Chimera Grid Tools Version 1.6 Released

Anew version of the Chimera Grid Tools (CGT), a set of

programs and scripts for generating overset grids, was

released. Developed at Ames Research Center, CGT is widely used for solving complex computational fluid dynamics

(CFD) problems in a variety of real-world applications,

including aerospace, marine, automotive, environmental,

and sports.

Among the many new capabilities for CGT version 1.6 are:

read and animate body dynamics by reading from a dynamics table file, or from an arbitrary user routine; read

CART3D triangles and q file (.triq) containing grid and

scalar functions; display scalar functions on triangles in

DIAGNOS; capability to run OVERFLOW-D to create offNews From NAS

2 Gridpoints

Continued from page 1
body Cartesian grids; and perform domain connectivity

compatibility with Tcl/Tk version 8.3.3. To get more details,

and find out how to get CGT, contact co-developer Stuart

Rogers in the NAS Division at rogers@nas.nasa.gov.

New Boron-Nitrogen Nanotube 

Research Published

Anew development in the field of nanotechnology by

NAS researcher Deepak Srivastava is described in

Physical Review B, (Vol. 63, pg. 195413, 2001). In

“Anisotropic Nanomechanics of Boron-Nitride Nanotubes:

Nanostructured Skin Effect,” Srivastava and colleagues

Madhu Menon (University of Kentucky) and Kyeong Jae

Cho (Stanford University) studied the way in which boronnitride (BN) nanotubes respond to compressive strains, and

their mode of plastic deformation. Their findings show that

BN nanotubes may be useful as reinforcing fibers in ultralight and strong functional composite materials. Additionally, such a material will exhibit an anisotropy against

external axial strains – when the nanotube structure is compressed from both sides, damage occurs to one side only.

“We have discovered an “anisotropic” mode of axial load

transfer in strained BN nanotubes,” says Srivastava. Based on

this finding, the team has proposed a “skin-effect” model of

nanocomposite materials with parallel-aligned zig-zag BN

nanotubes. “Such material, if fabricated, would limit structural damage to the “skin” side of the material and not the

inner core side,” Srivastava explains. “One application, for

example, might be to someday use this material in auto manufacturing, where damage in a collision could potentially be

limited to the outside of the vehicle.”

Srivastava and collaborators are now investigating the characteristics of nanotube-reinforced polymeric materials. BN

nanotubes could be tested as reinforcing fiber simulations in

functionally smart polymer composite materials of the

future. If such a hypothetical material were fabricated, it

would have numerous useful applications in transportation,

aerospace, and defense.

NASA’s Information Power Grid (IPG) team recently

received the NASA Group Achievement Award, presented to selected groups who make outstanding contributions to the agency’s mission.

The NASA Advanced Supercomputing (NAS) Division is

leading the effort to build and

test the IPG, a network of

high-performance computers,

data storage devices, and scientific instruments. Ames is

collaborating with colleagues

at Glenn and Langley Research

Centers on the project.

Presented at the annual

NASA Honor Awards Ceremony on July 26 at Ames, the

award cites the “successful

implementation of Information Power Grid and completion of the first two level-one

milestones” and recognizes

that the IPG will become the

service delivery model for

high-performance computing for NASA. In fiscal year

2000, the IPG team demonstrated a complete version of a

grid system and successfully performed high-speed data

access on the grid’s infrastructure. “I’m particularly happy

with the (NAS) organization’s tremendous progress over the

three years that IPG has been underway,” says NAS

Division Chief William J. Feiereisen. “Our work is now

being recognized in the world outside of NASA – people

are looking to us to find out

what to do in high-performance distributed computing.”

“The IPG is becoming the

model by which NASA accesses its high-performance computing resources,” says IPG

Project Manager William E.

Johnston. “Three years ago we

felt we had an opportunity to

fundamentally change the way

computing is done – and we

have accomplished that.” In

late July, Johnston met in

London with center directors

for IBM’s recently announced

grid initiative to present grid

implementation methods developed for the IPG. 

The IPG has been a major

project under NASA’s Information Technology and High

Performance Computing and Communications programs.

For more information on NASA’s Information Power Grid,

visit www.ipg.nasa.gov.

IPG Team Receives Prestigious NASA Award

Ames Research Center Deputy Director William E. Berry, left,

and Center Director Henry McDonald, far right, present the

NASA Group Achievement Award to the Information Power

Grid team, represented by Leigh Ann Tanner, IPG program

manager, and Arsi Viziri, IPG deputy project manager.

(NASA/Dominic Hart)

www.nas.nasa.gov/gridpoints Gridpoints 3
Breast cancer currently plagues more than two million

women in the United States – a startling 12.5 percent

of women in California alone. Suhrit K. Dey, professor of mathematics at Eastern Illinois University, is currently

collaborating with computer scientists in the NASA Advanced Supercomputing (NAS) Division to create mathematical models that will predict how cancer spreads in the

human body, and how it may be contained or even cured. 

Dey plans to integrate a technique called multi-level parallelism (MLP) into his three-dimensional modeling code to

enhance its computational performance on the NAS

Division’s 512-processor SGI Origin 3800 supercomputer,

Lomax. Dey’s mathematical models are based, in part, on his

theory that there is a direct correlation between stress levels

and the development of breast cancer (see Figure 1).

Dey is currently computing one-dimensional cancer models

using a set of eight mathematical equations. These models

include several variables such as the number of lymphocytes

(cells in the human body that attack cancer), number of cancer cells, types of medical treatments, angiogenesis (the

development of new blood vessels), and glucose levels in the

body (see Figure 2, page 5). “I am building these models

based on information I’m gathering in scientific journals,

which is qualitatively accurate. Once the models are complete, I will input an individual’s data to provide us with

some quantitative results – this will enable us to predict if

that individual will get cancer, or if their body’s immune system can revert the process,” explains Dey.

“Right now the problem I am solving is on a small scale, but

I am getting some qualitatively valued results which help me

communicate better with medical doctors,” says Dey. After

presenting his theory about the correlation between stress

and breast cancer, Dey has received a tremendous amount of

support from the medical community. 

“I feel that Dr. Dey’s approach is both novel and intriguing,

and could lead to important developments in this field.

What he offers is an overview approach that will give mathematical weight to many specific factors involved in causing,

preventing, and treating cancer,” says Dr. Steven Oppenheimer, director of the California State University at Northridge’s Center for Cancer and Developmental Biology.

The Three-Dimensional Approach

Dey is currently seeking a grant that will allow him to begin

generating three-dimensional cancer growth models. These

models will solve more than 16 million mathematical equations used to describe cancer growth. NAS computer scientists Jim Taft and Rupak Biswas are slated to parallelize Dey’s

cancer modeling code to run on Lomax, and will also assist

him with the integration of the multi-level parallelism technique, developed by Taft. Using three-dimensional cancer

models enabled by MLP, Dey will be able to predict the rate

of breast cancer growth and/or decay in an individual based

4 Gridpoints

Solving The Cancer Equation

A visiting professor at the NAS Division believes the key to winning the war

against breast cancer is using partial differential equations to model the spread of

cancer in individuals.

Blood Vessel

Red Blood Cells

Lymphocytes

Figure 1: Lymphocytes play a very important role in our

immune system by seeking out and destroying cancer cells. When

a person is under stress, hormones like glucocorticoid are released

into the blood stream, which significantly reduces the number of

lymphocytes present to fight off cancer cells. The figure shows

extremely slow cloning, or reproduction of lymphocytes in the

bloodstream as a result of stress.

(Visualization by Cliff Williams/NASA)
on their condition – levels of stress, amount of exercise, and

food intake, for example. 

In order to create a fairly accurate cancer prediction model,

all factors or conditions involved, such as the size of the

tumor and level of carcinogens in the body, must be considered at the same time. Since MLP is a shared memory technique, meaning all blocks of work have access to the same

area of memory on the computer simultaneously, it is ideal

for the cancer modeling code. “The kinds of problems that

Dey is doing require very rapid communication between different parts of the calculation in parallel – MLP will be able

to do this very efficiently. The fundamental construction of

Dey’s code structure is very similar to that of NASA’s computational fluid dynamics code OVERFLOW-MLP, which

contains many small blocks of work that have to communicate rapidly with each other. Because of these fundamental

similarities, we expect the code to scale well with MLP,”

explains Taft.

Collaborative Efforts Are A Must

Although Dey is returning to Eastern Illinois University at

the beginning of August, after a five-month visit at Ames, he

will continue collaborating with Taft and Biswas to carry out

his 3-D modeling work on Lomax. Once these models are

complete, Dey is planning to collaborate with mathematics

professor Glenn Webb at Vanderbilt University to expand on

the cancer prediction models. “Dr. Dey is developing elaborate models of tumor growth, incorporating multiple features

of tumor cell and immune cell interactions. The most interesting feature of these models is their exploration of the

importance of the immune system in controlling tumor

growth,” says Webb, who has been working on mathematical modeling of cancer for 30 years.

Although Dey’s mathematical models for cancer prediction

are qualitatively accurate, they are designed only to accompany clinical studies on breast cancer, not to replace them.

“We need a combination of mathematical models, statistical

models, and clinical studies, so we can see breast cancer from

every possible angle. I can see the light at the end of the tunnel. The solution is there, but desperately, I need help from

others so breast cancer can be contained,” says Dey. “If 10 percent of the people take an interest in this and protect themselves, that’s a large number of women being saved.”

—Holly A. Amundson

Editor’s note: Suhrit Dey welcomes and appreciates questions

and/or suggestions. Contact him at: cfskd@ux1.cts.eiu.edu, or

visit his website: www.ux1.eiu.edu/~cfskd

www.nas.nasa.gov/gridpoints Gridpoints 5

Figure 2: Immunostimulation (the activation of lymphocyte production) may be achieved through relaxation techniques (such as yoga

and meditation), regular exercise, diet, and/or some medications. When the immune system is strong, the body is able to stop the

growth of cancerous tumors. Reading the graph from right to left, the number of lymphocytes (green) is greater than the number of

cancer cells (red) — in this case, the immune system is able to conquer cancer. (Suhrit Dey)

(U) Red = number of cancer cells • (V) Green = number of lymphocytes, or T-cells • (M) Dark blue = medication used to assist thymus function • (S) Purple = medication that

kills both cancer cells and lymphocytes • (C) Aqua = carcinogens • (G) Yellow = glucose • (H) Black = medication that limits the amount of glucose consumed by cancer cells •

(B) Orange = vascularization (excessive growth of blood vessels that provide the cancer cells with more nutrients to grow)
The Earth may become one hot potato if pollutioninduced global warming continues to progress at its

current rate. Scientists at the U.S. National Center

for Atmospheric Research in Boulder, Colorado, predict

global temperatures will rise one to two degrees Fahrenheit

within the next 30 years, and three to nine degrees during

this century. Such temperature increases will have devastating

effects on the planet, causing polar ice caps to melt and raising sea levels, which will lead to flooding. Timothy Lee, from

the computational chemistry group in the NASA Advanced

Supercomputing (NAS) Division, is collaborating with Professor Joseph Francisco from Purdue University, West Lafayette, Indiana, to study compounds released in the atmosphere by industry and how they are contributing to the

amplified effects of global warming.

According to Lee, if there was no greenhouse effect, the surface temperature of the Earth would be approximately zero

degrees Fahrenheit, and the environment would be unable to

sustain human, animal, and plant life as we know it.

Through the greenhouse effect, (see Figure 1, page 7) the

Earth’s surface temperature is raised to about 58 degrees

Fahrenheit on average. The Earth radiates part of the energy

sent from the sun back into space though the atmospheric

window, which is defined as a set of wavelengths on the electromagnetic spectrum between 700 and 1,500 wave numbers (cm-1). In 1970, the radiation emitted from Earth was

measured during NASA’s Nimbus 4 Infrared Spectroscopy

Experiment. The problem arises when gases in the atmosphere, such as carbon dioxide, absorb too much radiation in

the window region, preventing it from escaping into space.

Heat trapped by greenhouse gases travels back to the Earth’s

surface, resulting in a significant rise in global temperature.

“Current research is showing that there is a strong link

between an increase in surface temperature and greenhouse

gases,” says Francisco. 

“The atmosphere is trapping energy that the Earth is transmitting, and reflecting some of the energy back to the surface

because it can’t escape through the atmospheric window,”

explains Lee. “We need the Earth to release some of this energy, otherwise the surface temperature will rise higher than it

is now.” 

Finding the Potential

To determine whether a particular compound in our atmosphere is contributing to the increase in global temperatures,

Lee and Francisco calculate the global warming potential

(GWP) of compounds using computational quantum chemistry methods – an approach to chemistry using mathematics and computers to describe chemical reactions and the

radiation properties of molecules. The GWP of a compound

is a measure of its impact on global warming over time as

a result of the release of a given amount of the greenhouse

gas into the atmosphere.

Compounds with large GWPs have a significant impact on

global warming, and generally have three characteristics: the

compound absorbs infrared radiation in the atmospheric

window region (instead of allowing the radiation to pass

through the window into space); absorption coefficients in

the window region are very high; and the compound has a

long atmospheric lifetime. All molecules possess characteristic vibrational frequencies, which may absorb infrared radiation depending on their absorption coefficients or infrared

intensities. The characteristic vibrational frequencies of a

given compound can be determined through quantum

chemistry calculations. Using such calculations, Lee and

Francisco have been able to explain why compounds like perfluorocarbons meet all three of GWP criteria, and therefore

have significant global warming potentials.

Compounds containing fluorine, for example, are always

going to have vibrational frequencies that lie in the atmospheric window because their stretching frequencies (dependent upon the bond strength and masses of the atoms) are

within the atmospheric window region. “A typical carbonfluorine stretch, for example, is around 800 cm-1 – which

falls within the atmospheric window,” explains Lee.

6 Gridpoints

The Heat is on...Earth

Computational Chemistry is being used to calculate the global warming potential

of industrial compounds being released into the Earth’s atmosphere, which 

are contributing to a rise in global surface temperatures.
Having an absorption in the window region, however, is not

enough to produce a significant global warming potential –

the compound must also meet the second point of the GWP

criteria that requires it to have a considerable absorption

coefficient, or infrared radiation intensity, to have an impact.

Fluorine, by nature, is a very electro-negative element –

when it is bonded to a weakly electro-negative or electropositive atom (as is the case with perfluorocarbons), it creates

a highly polar bond, or a large “movement” of charge from

one atom to another during the course of a stretching vibration. Generally, the more polar the bond, the more radiation

is absorbed by the stretching vibration. 

The third important component contributing to a large

global warming potential is the atmospheric lifetime.

Compounds that linger in the atmosphere for more than one

year, and in some cases in excess of 100 years, have a large

global warming potential, provided the other conditions are

met. Generally, atmospheric lifetimes of compounds are

based on reaction rates with hydroxyl radicals; the main

scrubbing agent the atmosphere uses to break compounds

down through chemical reactions. “Studies have shown that

reactions between hydroxyl radicals and perfluorocarbons

are very slow – they don’t react very well at all,” explains

Lee. “And when hydroxyl radicals react slowly with a

compound to break it up, it remains in the atmosphere for a

long time.” 

Compounds composed of more hydrogen atoms tend to

react faster with hydroxyl radicals (with methane being an

exception) relative to compounds such as perfluorocarbons,

which do not contain hydrogen atoms (perfluorocarbons are

composed only of carbon and fluorine atoms). Perfluorocarbons generally have an atmospheric lifetime of tens of

years, and in some cases, hundreds of years. “To solve the

problem, we must figure out what we can and can’t release

www.nas.nasa.gov/gridpoints Gridpoints 7

“Compared to ozone depletion, the level of understanding

of global warming is completely different — with ozone

depletion, there’s no question that humankind’s activities

are having a direct impact. With global warming, there are

only certain things you can deduce — if you release compounds with significant global warming potentials in the

atmosphere that are going to hang around for a 1,000

years, even in small amounts, it’s going to build up and

cause problems,” explains NAS researcher Timothy Lee. 

The physical processes of global warming and ozone depletion are very different. Global warming involves the release

of compounds into the atmosphere that absorb radiation

and trap it in the form of heat. Ozone depletion involves

chemical reactions that destroy ozone molecules in the

stratosphere, exposing Earth to high levels of the Sun’s

high-energy radiation. The ozone molecule is important to

life on Earth, because it absorbs the majority of highenergy radiation from the Sun, preventing it from hitting

the Earth’s surface. 

Ozone depletion occurs in the stratosphere – where the

ozone, which protects Earth from the Sun, is located.

Global warming occurs throughout the atmosphere,

although Lee and Francisco’s research is mainly concerned

with the troposphere (see Figure 1, above). According to

Lee, most of the compounds that cause ozone depletion

also have global warming potentials. These compounds are

non-toxic to humans, but quite detrimental to the ozone

layer. Ironically, some of the compounds that industry is

now using that were created to serve as chlorofluorocarbon

alternatives (such as aerosol propellants in hair spray cans)

to reduce ozone depletion will have a detrimental impact

on global warming. 

Global Warming vs. Ozone Depletion

MESOSPHERE

STRATOSPHERE

POSPH

(D) Heat trapped by 

Greenhouse gases 

(B) Earth emits 

blackbody 

radiation

(E) Infrared radiation 

absorbed by GHGs

(A) Sunlight 

Reaches Earth

Greenhouse Gases 

(GHGs) nearly 

transparent to 

sunlight

(C) Some radiation 

escapes to space through the 

"atmospheric window"

Figure 1: Ultraviolet radiation travels from the Sun to the

Earth’s surface, and some of this radiation is absorbed by the

surface, heating the planet (A). The Earth then emits blackbody radiation in the infrared spectral region (B). Some of the

emitted radiation escapes through the “atmospheric window”

into space (C). However, the remaining radiation is prevented

from escaping by greenhouse gases (GHGs) such as carbon dioxide, water, ozone, and other trace compounds, which causes

additional heating (D). The greenhouse effect is a natural

process; however, the greenhouse effect has been increased by the

release of dangerous compounds into the atmosphere from

industrial sources, which absorb strongly in the “atmospheric

window” (E).
from the Earth’s surface and then let the planet take care of

maintaining the atmosphere’s balance,” adds Lee.

A Unique Approach

Lee and Francisco’s use of computational quantum chemistry, rather than “traditional laboratory chemistry” is a new

approach to calculating global warming potentials. “We conduct experiments on the computer – our laboratory is the

computer,” explains Lee. “Some experiments are not easily

done in traditional labs, for example, in ozone depletion

chemistry, compounds that are stable in the stratosphere are

not stable at the Earth’s surface; the computer enables us to

carry out these otherwise dangerous experiments. For global

warming studies, infrared intensities are difficult to measure

in the lab, but are very straightforward to determine accurately using computational quantum chemistry methods.”

Lee and Francisco are calculating global warming potentials

for fluorinated and chlorinated compounds such as chlorofluorocarbons (CFCs), hydrofluorocarbons (HFCs), hydrochlorofluorocarbons (HCFCs), and perfluorocarbons (PFCs),

as well as others (see Figure 2).

“If you let certain compounds into the atmosphere, they

have the potential to slam the atmospheric window shut –

that would have a devastating impact,” explains Lee. “The

current challenge for scientists is designing new materials

that meet the constraints of having low ozone depletion

potentials, low global warming potentials, low toxicity, and

yet are still effective for a particular industrial use,” adds

Francisco. The ultimate goal of Lee and Francisco’s research

is to help industry decrease or eliminate the release of dangerous compounds by using global warming potential data to

guide new materials selection decisions. 

“Understanding how bond types and number of bonds influence a molecule’s global warming potential are essential to

developing molecular design strategies to minimize the global warming ability of new materials,” explains Francisco. “More

importantly, it should give industry more flexibility and

more options in developing environmentally benign materials.”

Once Lee and Francisco complete their calculations of global warming potentials, they will publish their results in scientific journals, and pass them on to modeling experts.

Scientific modelers will be able to incorporate Lee and

Francisco’s data into climate models demonstrating the

effects of different compounds on global warming. Because very little research has been undertaken to determine

the effects of perfluorocarbons and other fluorinated compounds on global warming, the impact that these compounds will have on global warming is not well appreciated

nor well understood.

— Holly A. Amundson

Editor’s note: Srinivasan Parthiban, a former post doctoral

student, also contributed to this research.

8 Gridpoints

Figure 2: Comparison of experimental results to computational chemistry calculations for the determination of

chlorofluorocarbon (CFC) infrared radiation absorptions in the atmospheric window region, 700 to 1,500 cm-1.

Experimental data for CFCs were used to benchmark the computational chemistry approach for calculating

infrared intensities.
National Aeronautics and Space Administration

DENVER, CO
2A NASA Research Centers: Ames • Glenn • Goddard • Jet Propulsion Laboratory • Langley • Marshall

Welcome, participants of SC2001.

As NASA Administrator, I am especially proud to welcome you to this important

conference. The technical papers to be presented, the demonstrations to be seen and

the professional friendships to be rekindled are exciting indeed. Gatherings such as

this give us the opportunity to be refreshed and rejuvenated about our work. I am

especially pleased to see that this conference not only features technical demonstrations, exhibits, and presentations, but that it also includes educational outreach.

Thank you to the corporate and academic partners who are making this aspect of

the conference possible.

Education is more important than ever. I have grave concerns about the future of

America’s leadership in science and technology because we have fewer and fewer

young people entering technical fields. It is up to all of us, including the participants

of this conference, to work with the high school and middle school teachers who are here to get young people interested–and excited–about technical fields, be it computing, networking, engineering, or...rocket science.

It is fitting that this year’s conference, titled “Beyond Boundaries,” is being held in Denver. This is a city poised at

the base of the Rocky Mountains–that set of spectacular mountains over which our forefathers had to cross and

endure as they continued the westward journey across this continent. We in technical fields in this country–mathematicians, scientists, engineers–face a formidable mountain range of sorts as we move through this new century...this

new millennium. Without the influx of young people, of new blood and new ideas, our country is doomed to lose

its leadership position in science and technology. So, give a special welcome to the teachers in your midst. Get to

know them, work with them as we move through the Rocky Mountains of our millennium toward a promised land of

opportunity for all.

Daniel S. Goldin

Daniel S. Goldin

NASA Administrator

Bill Ingalls/NASA

NASA is showcasing many of its exciting scientific research

projects at SC2001. The following are descriptions of

demonstrations, paper presentations, videos, and panel discussions listed by participating NASA researchers and collaborators.

Ames Research Center

Mountain View, California

As NASA’s Center of Excellence for Information Technology,

Ames Research Center (ARC) provides agency research leadership and world-class capability encompassing the fields of

supercomputing and networking, high-assurance software

development, verification, and validation, automated reasoning, planning and scheduling, and human factors.

NAS Grid Benchmarks

The NAS Grid Benchmarks (NGB) test the functionality

and efficiency of Grid environments such as NASA’s

Information Power Grid. NGB extends the methodology

of the NAS Parallel Benchmarks (NPB) to computational

Grids. It consists of four distributed applications, the elements of which are NPB codes that exchange substantial

data volumes.

The demonstration presents the first paper-and-pencil

specification of the NGB, which can be used by Grid developers and operators to test their environment. These

benchmarks also show prototype implementations using

Java and the Globus Metacomputing Toolkit. NGB nominally measures turnaround time. The Globus implementation also reports queue time and CPU time.

OVERSET Computational Fluid Dynamics Tools

This is a live demonstration of the NASA Ames OVERSET CFD software, including the Chimera Grid Tools,

Overgrid, and Pegasus. Researchers will demonstrate complete grid-generation for a number of different applications

from initial geometry definition to final preparation of all

the inputs for the flow solution. For more information:

visit: www.nas.nasa.gov/~rogers/home.html#software

ILab - Parameter Study Tool and 

Information Power Grid (IPG) Portal

The ILab tool was specifically written to solve the complex

problems of creating and launching parameter studies.

Though today’s distributed computational resources are

quite capable of running large parameter studies for aerospace problems, users have not had tools available that

make this process easy and fast. 

Within the last year, the ILab tool was given an intuitive

user interface. Users can now specify their processes via an

advanced CAD approach by visually constructing a flowchart-like graphic. ILab’s code generator subsequently transSPECIAL EDITION : NASA at Super Computing 2001
lates this into appropriate shell scripts, which are then

launched onto remote systems and monitored. Researchers

whose parameter studies consist of individual jobs with

long-running computational fluid dynamics problems can

now take advantage of ILab’s unique “restart” capability.

This allows users to automatically segment their jobs onto

supercomputer scheduling systems and modify solver parameters for the purpose of steering the computation to a

stable solution. Load balancing of jobs is automatically

accomplished by restarting the jobs onto supercomputer

systems with immediate processing availability. In addition,

ILab has an advanced help system built-in, which users can

access from any ILab screen.

Unsteady Turbopump For Reusable

Launch Vehicle (RLV)

The objective of this effort is to provide a computational

framework for design and analysis of the entire fuel supply

system of a liquid rocket engine, including high-fidelity

unsteady turbopump

flow analysis. This is

needed to support the

design of pump subsystems for advanced

space transportation

vehicles that are likely

to involve liquid propulsion systems. To

date, computational

tools for design/analysis of turbopump flows

are based on relatively

lower fidelity methods. An unsteady,

three-dimensional viscous flow analysis tool involving stationary and rotational components for the entire turbopump assembly has not been available for real-world engineering applications. The present effort will provide developers with information such as transient flow phenomena

at start up, impact of non-uniform inflows, and system

vibration and impact on the structure.

DeBakey Heart Assist Device

Approximately 20 million people worldwide suffer annually from heart failure, a quarter of them in America alone.

In the United States, an alarmingly low 2,500 donor hearts

are available each year. The use of Computational Fluid

Dynamics (CFD) technology has lead to major design improvements on the heart assist device, enabling its human

implantation. NASA Ames scientists employed NASA

Shuttle main engine technology and NASA CFD modeling

capabilities, coupled with the NASA Advanced Supercomputing (NAS) Division’s high-performance computing technology, to make several design modifications that vastly

improved the heart device’s performance.

Exploratory Computing Environments

Component Framework

Exploratory computing environments is a component

framework designed to enhance the ability of NASA scientists to visualize, analyze and interact with huge datasets

and associated distributed computations. The components

include a data model (Field Model (FM)), a metadata model

(Active Metadata (AM)), a visualization technique library

(VisTech), web technologies (Mars landing site problem

solving environment), and distributed object technology

(growler). Together, the components enable rapid prototyping

and development of distributed computational environments. Application domains include aeronautics, earth science, biology and nanotechnology.

NASA Research Centers: Ames • Glenn • Goddard • Jet Propulsion Laboratory • Langley • Marshall 3A

The NASA X38 Crew Return Vehicle was the subject of a

two-dimensional parameter study in Mach number and

angle-of-attack. ILab generated and submitted 192 separate

flow field computations for the requested 16 values of Mach

number and 12 values of angle-of-attack.

(NASA/Maurice Yarrow)

Visual comparison of the original ventricular assist device,

top, and the unit after modifications by NAS researchers,

lower. Adding an inducer to the DeBakey device eliminates

the dangerous back flow of blood by increasing pressure and

making flow more continuous. The device is subjected to the

highest pressure around the blade tips, shown in magenta.

(NASA/Cetin Kiris)

Visualization of the entire fuel supply system of a liquid rocket engine,

including high-fidelity unsteady

turbopump flow analysis. (NASA)

SPECIAL EDITION : NASA at SuperComputing 2001
Parallel Distributed CFD for Unsteady

Flows with Moving Overset Grids

The goal of this work is to develop techniques for parallel

and distributed computations of large-scale unsteady moving body applications using overset structured grids. The

flow domain is decomposed into a union of multiblock

meshes, which may be in relative motion to one another.

An approach based on the message-passing Chimera paradigm has been implemented in the OVERFLOW-D code

with the Globus-MPICH-G toolkit that extends the execution

environment to the IPG. Performance assessment of a largescale Navier-Stokes problem consisting of a moving body grid

system (approximately 37 million points) indicates the feasibility of wide area networks for this class of applications.

Mars Surveyor Landing Sites “Collaboratory”

Marsoweb is as a web-based interactive archive of data for

selection of landing sites for the 2003 Mars Explorer Rover

missions. This archive allows visual navigation of the candidate landing sites and various maps of data from the current Mars Global Surveyor (MGS) mission and from the

Viking missions, including high-resolution images of the

candidate sites. VRML scenes allow the user to roam the

data in 3-D on the web. Marsoweb also features interactive

archives of global data, which enable users to query MGS

4A NASA Research Centers: Ames • Glenn • Goddard • Jet Propulsion Laboratory • Langley • Marshall

Marsoweb home page at: http://marsoweb.nas.nasa.gov/

landingsites.

Particle traces around a moving body problem. 

(NASA/M. Jahed Djomehri)

IP Multicast for Seamless 

Support of Remote Science

Scientific investigations at remote locations on Earth can be tremendously enhanced by connectivity to existing networks that use standard protocols. This demonstration showcases the capability to both

send and receive high-fidelity images using Internet Protocol (IP) multicast (via geosynchronous satellites) with the NASA Research and

Education Network/Glenn Research Center (NREN/GRC) Transportable Earth Station (TES). A 20 Mbps IP multicast of previously

stored video content is sent via satellite from a server at GRC to client

machines at SC2001. With IP multicast, the satellite and network

capacities are used optimally, regardless of the number of participants,

yet the distribution of the signal can be limited to a specific group. For

more information, visit: http://www.nren.nasa.gov

Ready access to high quality imagery and data improves the performance

of remote scientists and increases the quality of their results. (NASA)

SPECIAL EDITION : NASA at Super Computing 2001
data maps and geology maps. Current development efforts

include remote collaboration features and Venus topography data. For more information, visit: http://marsoweb.nas.

nasa.gov/landingsites

Debugging on the Information Power Grid 

This demonstration showcases three aspects of debugging

on the Information Power Grid. First, researchers will show

how a debugger can control the execution of a computation

running on a heterogeneous collection of machines. This is

a key requirement of a debugger for computational grids.

Second, researchers will demonstrate how the debugging of

tool-parallelized codes can be mechanized through the use

of dependence analysis information, and a relative debugging approach that compares the executions of the parallel

and serial codes. Finally, trace information collected during

a computation will be used to provide a number of highly

useful debugging operations. For more information, visit:

www.nas.nasa.gov/Tools/p2d2/SC01

Control and Observation in

Distributed Environments

Researchers in the NAS Division at NASA Ames Research

Center have developed a software framework, called CODE,

for control and observation in distributed environments.

This program allows researchers to observe and control

resources, services, and applications in large-scale distributed systems. CODE provides a secure, scalable, and extensible framework to make observations, reason about observations, and perform actions to adjust how an observed

entity is operating.

Administrators can use CODE to manage a computational grid by observing the resources and services that make up

a grid and controlling their operation. In ongoing work,

NAS researchers are using the CODE framework to provide grid information to a searchable, distributed directory

service available to grid users. For more information, visit:

www.nas.nasa. gov/~wwsmith/CODE

‘growler’ Visualization Tool

The “growler” environment provides an infrastructure that

allows various kinds of functional modules to be “wired”

together to create distributed and collaborative scientific

applications. The individual components can be local or

remote – that is, an application can be installed on a single

machine, or it can be distributed over a network. Scientific

visualization applications are typically decomposed into

viewer components and data components. The viewers perform graphics and take in user input. The data components

provide data – either from archival databases, from ongoing

simulations, from instruments, from analysis procedures,

or from some combination of these. 

The growler environment allows researchers to combine a

diversity of viewer and data components in order to create

a wide variety of custom-tailored utilities. For example,

multiple viewers can be attached to a data stream to create

a collaborative facility. Or a single viewer can receive input

from multiple data sources, creating a single “console” for

overseeing control and results from a multi-stage, distributed computation.

John H. Glenn Research Center

Cleveland, Ohio

Glenn Research Center (GRC) is NASA’s Lead Center for

Aeropropulsion and Center of Excellence in Turbo-machinery.

GRC is committed to developing innovative technology and

leveraging its computational, analytical, and experimental

expertise in turbomachinery to future aerospace programs.

GRC’s aeropropulsion program plays a significant role in promoting safe and environmentally compatible U.S. aircraft

propulsion systems.

NPSS: NASA Software of the Year

The Numerical Propulsion System Simulation (NPSS)

Version 1 was selected co-winner of the NASA Software of

the Year Award for 2001. Numerical Propulsion System

Simulation Version 1 also received the NASA Office of

Aerospace Technology Turning Goals into Reality Award

for Goal 3 Pioneering Technology Innovation.

NPSS Version 1 is a world-class propulsion system simulation tool that provides the user with unprecedented capability and ease of use. NPSS Version 1 is an emerging U.S.

standard for aerospace simulations. NPSS Version 1 is the

first major aerospace design and analysis tool developed

and written in the object-oriented (OO) programming paradigm to improve engineering productivity. NPSS’ new

OO software architecture enables multi-fidelity analysis in

the design environment and facilitates integration of multiple disciplines. For more information, visit: http://hpcc.

lerc.nasa.gov/npssintro.shtml

NASA Research Centers: Ames • Glenn • Goddard • Jet Propulsion Laboratory • Langley • Marshall 5A

Visualization of a vitamin B-12 molecule using the growler

application. (NASA/Chris Henze)

SPECIAL EDITION : NASA at SuperComputing 2001
Project Integration Architecture:

CAD Geometry Capture

The Project Integration Architecture (PIA) is a distributed,

object-oriented, wrapping architecture for capturing,

encapsulating, presenting, and integrating all elements of

day-to-day technical activity including, but not limited to

experiment, design, analysis, simulation, and optimization.

The benefits of PIA are: fast and direct access to data of

many formats, accurate capture of information, and convenient data archiving in a single environment. For more

information, visit: www.grc.nasa.gov/WWW/price000

Portable Virtual Reality Environment

The portable virtual reality environment at Glenn Research

Center’s Graphics Visualization Laboratory allows researchers and engineers to explore their scientific data in a 3-D

environment. Researchers move around in the environment using a wand and wear special “flicker” glasses to see

the images in 3-D. This interaction allows the researcher to

closely examine any part of their data. Virtual Reality offers

interactive computer graphics that provide a viewer-centered perspective and a large field of view. For more information visit: http://gvis.grc.nasa.gov/

or http:// gruve.grc.nasa.gov/

Hybrid Satellite Communications

The Transportable Earth Station (TES) is designed to support high data rate networking experiments into highly

remote areas where terrestrial connectivity is poor or nonexistent. The earth station is a completely self-contained

Ku-band system, able to simultaneously send and receive

6A NASA Research Centers: Ames • Glenn • Goddard • Jet Propulsion Laboratory • Langley • Marshall

A NASA researcher explores data from a turbomachinery

simulation using the portable virtual reality environment.

(NASA/GRC)

The goal of the NASA Aviation Safety Program (AvSP)

is to “develop and demonstrate technologies that contribute to a reduction in aviation accident and fatality

rates by a factor of five by year 2007 and a

factor of 10 by year 2022.”

Large volumes of flight data are collected continuously by airport flight-tracking telemetry

facilities. This dataset consists of the radar

tracks of all incoming and departing aircraft

and could be processed to evaluate and track

the engine performance of monitored aircraft.

Data processing in this scenario is problematic in that it requires three basic elements: an

engine simulation, high-end computing

resources, and a job scheduler.

NASA Glenn Research Center has worked to

provide a solution to this problem by developing a job scheduler that processes large

numbers of engine simulations using the

Numerical Propulsion System Simulations

(NPSS). Simulations are executed on the

high-end computing resources made available

by the NASA Information Power Grid (IPG). For more

information, visit: http://accl.grc.nasa.gov/rgriffin/AVSP/

Presentation/AVSPDEMO.htm

Collecting flight data with telemetry stations for processing with

Numerical Propulsion System Simulations. (NASA/GRC)

Glenn Research Center:

Aviation Safety Using NPSS on the IPG

SPECIAL EDITION : NASA at Super Computing 2001
up to 50-Mbps data streams. The station is mounted on a

20-foot-long trailer and is towed by an Econoline van. No

special permits or licenses are required to drive the van and

trailer across public highways.

This endeavor represents a first step toward providing support for mobile and nomadic science within NASA. The

TES can be driven to a site, parked, the antenna deployed,

and the system used for satellite access to provide temporary networking facilities at that site. Potential applications

of the TES include support for mobile networking technology development, workshops and conferences, scientific field studies, and international collaborations. For more

information, visit: www.nren.nasa.gov

Goddard Space Flight Center

Greenbelt, Maryland

Goddard Space Flight Center (GSFC) seeks to expand knowledge of the Earth and its environment, the solar system, and

the universe through observations from space. High-performance computing interprets observational data both by processing it into understandable forms and by simulating observed

and unobserved phenomena.

HDTV Visualizations of Earth 

and Space Science

As scientists rely more on simulations and observations to

understand nature, they are confronted by massive

amounts of data to sift through and analyze. With data volumes at billions, even trillions of bytes visualization enables

scientists to see the physical processes at work.

GSFC has created high-definition data visualizations of

Earth and space phenomena. Presented in the HDTV

(High Definition TV) format, visualizations shown at SC2001

include: Climate models probing the coupled ocean-landatmosphere response to seasonal variability such as El

Niño/La Niña; multi-year views of global ozone and plant

life; a Mars terrain fly-over; zoom-ins to several U.S. cities

that seamlessly combine four data sets. For more information, visit: http://svs.gsfc.nasa.gov

Journeys through Earth and Space

Why are the Rocky Mountains so far inland? How do we

preserve the changing Amazon rain forest? When will the

sun fling parts of itself towards Earth? NASA is tackling

questions like these inside supercomputers. Here, billions

of calculations per second recreate the universe mathematically. Supercomputers can process observations into a

motion picture. Or, they can solve equations that describe

realities seen and unseen.

To understand and predict nature through computation,

NASA started the Earth and Space Sciences (ESS) Project,

which is now leading the Earth Science Technology Office’s

Computational Technologies effort. This video magazine

follows three ESS research teams on their journeys to discovery. For more information, visit: http://ess.gsfc.nasa.gov

qDoc: A Documentation and Presentation Tool

qDoc provides a means for simply documenting Fortran

source code and making that documentation available via a

NASA Research Centers: Ames • Glenn • Goddard • Jet Propulsion Laboratory • Langley • Marshall 7A

Satellite Terminal Internet Next Generation (STING) transportable earth station. (NASA)

Sun and magnetic field lines. (Goddard Space Flight Center

and Naval Research Laboratory)

Olympus Mons on Mars. (MOLA)

SPECIAL EDITION : NASA at SuperComputing 2001
web browser. Documentation elements include logical

source code blocks and definitions of variables, parameters,

and routines.

Users insert code documentation directly into the source by

means of comment characters appended with minimal

character sequences describing qDoc actions. Documentation may be plain text or LaTeX commands. The code

may also be sectioned into chunks for display in an expandable/collapsible HTML document format. All utilities are

accessible via a user-friendly GUI enabling full or partial

processing of individual or multiple files.

GLOBE Program: Multi-Agency International

Educational Outreach

The GLOBE (Global Learning and Observations to

Benefit the Environment) Program involves over 11,000

schools in 97 countries in observing and reporting data on

environmental phenomena. The NASA GSFC GLOBE

team visualizes the millions of GLOBE observations that

have been reported since 1995 and makes these visualizations available on the GLOBE website.

The GLOBE visualizations can show more than 60 student

datasets on the web on the same day that they are taken!

Seventeen zoom levels range from whole Earth maps down

to 25 x 25 km, and up to six schools or datasets can be

shown on a single time graph. For more information, visit:

www.globe.gov

Beowulf Technology and Applications

Beowulf-class computers are becoming the dominant architecture in parallel computing. In this demo, a number of

technologies are presented that take advantage of or extend

the traditional Beowulf paradigm. The Beowulf system

software display showcases PVFS: The Parallel Virtual File

System, a high-performance filesystem for Beowulfs, and

BNT: Beowulf Network Transport, a replacement for TCP

optimized for a Beowulf’s internal network. The problem

solving environment display showcases new areas for creating applications. The mini-grid section presents a system

of interconnected Beowulfs capable of sharing resources.

The Adaptive Computing Cluster display presents a merger of field-programmable gate array technology with the

network interface in a Beowulf cluster. For more information, visit: www.parl.clemson.edu/

Jet Propulsion Laboratory

Pasadena, California

The Jet Propulsion Laboratory (JPL), managed by the

California Institute of Technology, is NASA’s lead center for

robotic exploration of the solar system. JPL telescopes are

8A NASA Research Centers: Ames • Glenn • Goddard • Jet Propulsion Laboratory • Langley • Marshall

The Mars Site Terrain Generator can be used for producing high resolution (less than 1 km) site terrain based on

spacecraft instrument data from

prior missions. The data from diverse

sources are reconciled and rendered

into site models in near real time. In

turn, Mars site terrain models can be

synthetically enhanced with much

higher resolutions (to approximately

1 cm) features to support high fidelity simulation of landing and landed

(Rover) operation. Monte Carlo simulations compute the likely rover

performance averaged over a large

number of trials and in the presence

of a large number of uncertain variables. Results from these simulations can provide valuable

input for design and risk assessments.

Synthetic Mars terrain generation uses

data collected by previous missions

and sensors to generate terrain models,

which can be enhanced to simulate

landing and surface (Rover) missions.

(NASA/JPL)

Jet Propulsion Lab:

Mars Site Terrain Generation Using Supercomputing

SPECIAL EDITION : NASA at Super Computing 2001
observing distant galaxies in the universe to study how the

solar system was formed. JPL also manages the worldwide

Deep Space Network, which communicates with spacecraft

and conducts scientific investigations. To support NASA’s continued exploration, JPL is making advances in technology

with new instruments and computer programs to help spaceships travel further and telescopes see farther than ever before.

Supercomputing for the National 

Virtual Observatory

The National Virtual Observatory (NVO) is being built by

the astronomy community, with emphasis on many interoperable components, existing in a distributed highperformance, scalable environment. The clients themselves

can be anywhere and do not need specialized or highperformance capabilities. 

The dramatic growth in aperture and focal plane capabilities of institutionally managed observatories has resulted in

an avalanche of data, both image and catalog. NVO is conceptualized to deal with these data by developing a layered,

interoperable software architecture wedded to the Internet

II with its national network of computational resources.

For more information, visit: http://yoursky.jpl.nasa.gov

Langley Research Center

Hampton, Virginia

In alliance with industry, other agencies, academia, and the

atmospheric research community, Langley Research Center

(LaRC) undertakes innovative, high-payoff aerospace and scientific activities beyond the risk limit or capability of commercial enterprises and delivers validated technology, scientific knowledge, and understanding of the Earth’s atmosphere.

ISS Environment Simulator: 

An Immersive Application

The International Space Station Environment Simulator

(ISSES) is a virtual reality application that uses highperformance computing, graphics, and audio rendering to

simulate the radiation and acoustic environments of the

International Space Station (ISS). The user can maneuver

to different locations inside or outside of the ISS and interactively compute and display the radiation dose at a point. 

NASA Research Centers: Ames • Glenn • Goddard • Jet Propulsion Laboratory • Langley • Marshall 9A

At Langley Research Center, the Environment for Launch

Vehicle Integrated Synthesis (ELVIS) is being developed

to apply high-performance computing technologies to

multidisciplinary design optimization (MDO) of

Reusable Launch Vehicles (RLV).

Various discipline codes are

being integrated using commercially developed framework software that allows the

use of networked heterogeneous computing resources.

The framework also allows

easy addition or deletion of

analysis codes and facilitates

changes in the control flow of

the MDO process through a

graphical user interface.

Currently, three prototype

applications are being developed: Simulation of vehicle

ascent system analysis using

four disciplines with parallelized trajectory optimization; computation of vehicle

weights using finite element

models of major vehicle structures coupled to parallel implementation of HyperSizer

for structural sizing; and generation of aerothermal

database and thermal protection system sizing for a complete vehicle using high-fidelity codes and coarse- and

fine-grained parallelism.

Conceptual launch vehicle configuration displayed on ELVIS. (NASA)

Langley Research Center:

Environment for Launch Vehicle Integrated Synthesis

SPECIAL EDITION : NASA at SuperComputing 2001
Omnidirectional and localized sounds are

rendered over headphones by a separate

server that receives real-time updates on the

user’s position and orientation. Changes can

be made to equipment rack locations,

which produce changes in both the radiation shielding and system noise. 

This application allows for interactive investigation and trade studies between radiation

shielding and noise for crew safety and

comfort. For more information, visit: 

http://acmb.larc.nasa.gov/

10A NASA Research Centers: Ames • Glenn • Goddard • Jet Propulsion Laboratory • Langley • Marshall

Examination of a Radiation Dose Point using

the International Space Station Environment

Simulator. (NASA)

Marshall Space Flight Center (MSFC) leads the Space

Launch Initiative (SLI), the key to opening the space frontier for continued scientific exploration and economic expansion. SLI will make space flight safe and affordable for both

the government and private industry. SLI is the centerpiece

of NASA’s long-range Integrated Space Transportation Plan,

which also includes near-term Space Shuttle safety upgrades

and long-term research and development for third generation reusable launch vehicle technologies and in-space transportation systems.

The haptic interface, one of many

emerging multisensory technologies, allows the user to touch and

feel computer generated models

and data. The use of multisensory

techniques increases the bandwidth

between computers and the brain.

With the haptic workstation, the

user can physically interpret the

nuances of a computational fluid

dynamics (CFD) simulation, that

is, to touch, feel, and trace the

shape of phenomena such as microvortices, or secondary shock waves.

For more information, visit:

http://anvil.msfc. nasa.gov

Data Visualization with Haptic Feedback

Huntsville, Alabama

Marshall Space Flight Center

Researcher wearing LCD shutter-glasses, holding haptic stylus interacts with CFD data image of a reusable

launch vehicle (behind and inset). (MSFC/NASA) 

SPECIAL EDITION : NASA at Super Computing 2001
NASA Research Centers: Ames • Glenn • Goddard • Jet Propulsion Laboratory • Langley • Marshall 11A

Technical Papers

Tuesday, November 13

Session: Material Science Applications

1:30 p.m. to 3 p.m.

Scalable Atomistic Simulation Algorithms

for Materials Research 

Authors: Aiichiro Nakano, Rajiv K. Kalia, Priya Vashishta

(Louisiana State University); Timothy J. Campbell (Logicon

Inc. and Naval Oceanographic Office Major Shared Resource

Center); Shuji Ogata (Yamaguchi University, Japan); Fuyuki

Shimojo (Hiroshima University, Japan); and Subhash Saini

(NASA Ames Research Center).

A suite of scalable atomistic simulation programs has been

developed for materials research based on space-time multiresolution algorithms. Design and analysis of parallel algorithms are presented for molecular dynamics (MD) simulations and quantum-mechanical (QM) calculations based

on the density functional theory. Performance tests have

been carried out on 1,088-processor Cray T3E and 1,280-

processor IBM SP3 computers. 

The linear-scaling algorithms have enabled 6.44-billionatom MD and 111,000-atom QM calculations on 1,024

SP3 processors with parallel efficiency well over 90 percent.

The production-quality programs also feature waveletbased computational-space decomposition for adaptive

load balancing, space-filling, curve-based adaptive data

compression with user-defined error bound for scalable

input/output, and octree-based fast visibility culling for

immersive and interactive visualization of massive simulation data.

Presentations

SGI 1,024 CPU Origin System

Presented by John Ziebarth, deputy division chief,

NASA Advanced Supercomputing Division

In cooperative development with SGI, the first 1,024

processor shared memory computer was booted on July 26,

2001, at NASA Ames. By providing coherent shared memory across 1,024 processors, this system clearly pushes

shared memory technology beyond previous limits. Over

the past weeks, an enhanced topology for both the 512 and

1024 systems were developed with first boot in October.

MLP Scaling on NASA’s Origin 

1,024 CPU System

Presented by James R. Taft,

Advanced Computing Technologies, NAS Division 

NASA Ames has developed a very simple and highly scalable method for parallelizing a number of production applications used in critical NASA missions. The new technique, called shared memory multi-level parallelism, or MLP,

is a user callable library of three routines. Scaling results for

a full aircraft simulation, climate modeling, and a simulation of the space shuttle main engine all demonstrate superior performance over previous approaches. 

These recent increases in code performance have had a

major impact on NASA science. Highly resolved full aircraft

simulations with the RANS code OVERFLOW are now

done in a few hours instead of weeks. Climate predictions

are 10 times faster than just a few months ago, allowing scientists to attempt simulations not possible just last year.

Finally, simulations of turbomachinery for the SSME are

executing 10 times faster, allowing much more detailed and

timely exploration of the behavior of new designs.

Workshops

Monday, November 12 • 8:30 a.m. to 5 p.m.

Grid 2001: Second International Workshop

on Grid Computing

Session V (4:15 to 5:30 p.m.) – Performance and Practice. 

Discussion will cover performance contracts, The DO

Experiment Data Grid-SAM, and Production-Level Distributed Parameteric Study Capabilities for the Grid, which

will be presented by the following NASA Ames researchers:

Maurice Yarrow, Karen M. McCann, and Adrian DeVivo,

and Edward Tejnil.

Panels

Friday, November 16 • 8:30 a.m. to 10 a.m.

HPC Software: Have We Succeeded in 

Spite of it, or Because of it?

Moderator: John M. Levesque

Panelists: Walt Brainerd, Chris Doehlert, Michael Gittings,

Bill Gropp, David Kuck, James R. Taft, technical director,

Advanced Computing Technologies, NASA Ames.

The moderator believes that we have succeeded in spite of

HPC software. The state of HPC software is poor at best

and the future of HPC software is dismal. The current

thrust towards Linux and open source software does not

bode well for software. This panel’s discussion is targeted at

a few specific problem areas such as software standards, and

high performance computing software research in the academic arena.

NASA Participation: Presentations and Papers

On the cover:

Echo Lake with Mount Evans in the background. The road to

the top of Mount Evans is the highest in North America

climbing to 14,260 feet above sea level. The summit is 60

miles from Denver. (Richard Grant, Denver Metro Convention and Visitors Bureau)

SPECIAL EDITION : NASA at SuperComputing 2001
12A NASA Research Centers: Ames • Glenn • Goddard • Jet Propulsion Laboratory • Langley • Marshall

Q

A

B

R

R

C D

E

F

G

P

O

M

N

K

L

J

H

I

Information

Immersive

 Workbench

NASA Theater

NASA Theater – presented by: Panoram Technologies Inc. 

Presentations:

• Mars Site Terrain Generation Using Supercomputing

• Mars Terrain Modeling and Rover Mission Simulation Using Supercomputing

• Supercomputing for the National Virtual Observatory

• Quantum Dot Modeling Using NEMO-3D

• IPG - A Large Scale Distributed Computing and Data Management System

• MLP Scaling on NASA’s Origin 1024 CPU System

• SGI 1024 CPU Origin System

• NAS Grid Benchmarks

• growler - A Component-Based Framework for Distributed/Collaborative 

 Scientific Visualization and Computational Steering

• HDTV Visualizations of Earth and Space Science

• Data Visualization with Haptic Feedback; Space Launch Initiative Advanced 

 Engineering Environment (AEE) 

• Glenn Research Center Video Stream

Videos:

• Journeys through Earth and Space

• Nanotechnology Video

• Powered-Lift Vehicle Simulation

• DeBakey Heart Assist Device

• Adaptable Computing Cluster

• Beowulf System Software

• Problem Solving Environment Framework

• Computational Mini-Grids

Data Visualization with Haptic Feedback

Space Launch Initiative Advanced Engineering 

Environment (AEE)

Data Mining on the Information Power Grid (IPG)

DeBakey Heart Assist Device

• Mars Surveyor Landing Sites “Collaboratory”

• Unsteady Turbopump for Reusable Launch Vehicle

IP Multicast for Seamless Support of Remote Science

• Transportable Earth Station (TES)

• Project Integration Architecture (PIA)

• Glenn Reconfigurable User-interface and Virtual

 reality Exploration (GRUVE)

• ISS Environment Simulator: An Immersive

 Application

• Debugging on the Information Power Grid (IPG)

• Exploratory Computing Environments 

 Component Framework

• Control and Observation in Distributed

 Environments

growler - A Component-Based Framework for 

Distributed/Collaborative Scientific Visualization 

and Computational Steering

• OVERSET Computational Fluid Dynamics Tools

• Parallel and Distributed CFD for Unsteady Flows 

 with Moving Overset Grids

• ILAB: Parameter Study Creation and Submission

 on the Information Power Grid (IPG)

• NAS Grid Benchmarks

qDoc: A Documentation and Presentation Tool

Numerical Propulsion System Simulation (NPSS) Kiosk

Aviation Safety Using Numerical Propulsion System 

Simulation (NPSS) on the Information Power Grid (IPG)

 

Environment for Launch Vehicle Integrated Synthesis 

(ELVIS)

GLOBE Program: Multi-Agency International 

Educational Outreach

A

B

C

D

E

F

G

H

I

J

K

L

M

N

O

P

Q

SPECIAL EDITION : NASA at Super Computing 2001
The vision of NASA’s Information Power Grid is that

of an environment where high-end computing resources are as ubiquitous and easy to use as the electrical grid is today. One key aspect contributing to the success of the nation’s power grid is standards: From the shape

of outlets to the voltages and frequencies that those outlets

provide, users can count on a certain uniformity that

allows their appliances to work throughout the network,

wherever they plug in.

For applications on an information grid,

there are also advantages to standards. Networking infrastructure

standards, such as TCP/IP (Transmission Control Protocol/ Internet

Protocol), were key to the growth

of the Internet. Higher-level standards, such as HTML, were also

key to the explosive growth of the

web. These conventions enable information exchange and provide a common

model for some of the most prevalent types of

meshes and fields in the information universe.

For scientific applications – especially those associated with

high-performance numerical computing – some of the most

widely encountered object types are meshes, and fields based

on those meshes. A mesh represents a discretization of a

space, a decomposition into many thousands, or in some

cases millions, of smaller-sized objects known as cells. Fields

are defined by associating values with the cells. In computational fluid dynamics (CFD), typical examples of fields include the momentum, density, and energy fields surrounding

an aircraft. In computational chemistry, a typical area of

interest would be the electron density field surrounding a

molecule. Even though these disciplines may seem unrelated,

the underlying commonality of meshes and fields

provides opportunities for us to develop common data models. Such models in turn open the

door to enhanced sharing of data and reuse of

analysis software.

Researchers in the NASA Advanced Supercomputing Division are developing a software component

for mesh and field data known as “Field Model”

(FM), a growing library of classes written in

templated C++. Built on top of the core set of

classes are modules that handle various file formats and the idiosyncrasies specific to different

data standards. For example, there is a PLOT3D

module that makes it easy for the user to read data

files conforming to the PLOT3D format, a frequently

used standard in computational fluid dynamics.

FM is a follow-on to the Field Encapsulation Library, an earlier data model project (see Learn More, page 13). FM is

www.nas.nasa.gov/gridpoints Gridpoints 9

Field Model: Developing A

Scientific Data Model

Field Model is designed to enable the sharing of data from a

variety of scientific disciplines, as well as increase the reuse of

analysis and visualization software components.

By Patrick J. Moran

Above: The tori are an example of one of the types of unstructured meshes that can be represented by Field Model. In a

broader sense, the interlinked objects symbolize how software

components, such as FM, interrelate within larger component

frameworks. (Patrick Moran)
more general and flexible than the Field Encapsulation

Library, and is applicable to a broader range of data; the

current effort builds on lessons learned from the previous

generation of software.

Field Model as a Data Nexus

Scientists are confronted with an ever growing volume of

data, from a variety of sources. A well-designed data model

can help. First, a data model can provide a “common

ground,” in other words, a means for bringing data from a

variety of sources into a common environment. This common model enables easier comparative studies. For instance, one could bring data from a

variety of sensors into a single analysis application. The common model also provides

advantages researchers and developers of

analysis techniques. By bringing the data into

a common model, more opportunities are created for applying analysis modules

that may have been originally developed for one scientific discipline

to another.

An excellent example of how the

system works is provided by NASA’s

Earth Observing System (EOS)

Terra satellite, which orbits the

planet collecting data on a minuteby-minute basis. Data archived by

the EOS is made available to scientists in an extended version of the

Hierarchal Data Format (HDF) file

format, which was developed jointly between the EOS program and

the National Center for Supercomputing Applications (NCSA).

Figure 1 illustrates a swath, one type

of data contained in HDF-EOS files.

Swaths are data acquired by a

remote sensor as it sweeps over a

region of the Earth. FM provides

modules that bridge the gap

between specific file formats and the central data model.

The HDF-EOS module can import EOS data into FM

object instances. 

Earth science data provides some relatively distinct challenges for a data model: complex projections plus a variety of

numeric types, including integer types, are typical. The virtual function interface and templating features of FM

address these challenges. Behind the virtual function interface, FM classes can apply routines to compute various projection transformations on the fly. Because field node types

10 Gridpoints

Figure 1: The visualization of the U.S. Gulf Coast region is based upon L1B swath data

acquired September 29, 2000, by the Moderate Resolution Imaging Spectrometer (MODIS)

instrument aboard the Terra satellite. Terra is the flagship in NASA’s Earth Observing

System (EOS). The datasets are made available by the Distributed Active Archive Center

(DAAC) based at Goddard Space Flight Center. (Timothy Sandstrom)

Figure 2: This image shows a pattern of excitatory input impinging on a sensory interneuron

from the abdomen of a cricket. The interneuron

receives this input from a large number of windsensitive hair cells that create a 3D pattern of

excitation (a "neural map") encoding wind

direction and magnitude. The map has been

idealized as a continuous excitatory field and

computationally "masked" onto the interneuron

using the Field Model. (Data courtesy Gwen A.

Jacobs, Department of Cell Biology and

Neuroscience, Montana State University; image

by Chris Henze, NAS Division)
are templated, researchers can reuse the same

FM implementations for both fixed-point and

floating-point fields.

Another example of FM’s versatility is shown

in a molecular dataset based on vitamin B-12

(see Figures 3 and 4). In addition to molecular

coordinates, the dataset includes the Laplacian

(sum of the second-order partial derivatives) of

the electron density field, sampled on a regular

mesh in the region containing the molecule.

FM includes mesh and field classes that exploit

various optimization opportunities. For example, the FM regular mesh class underlying the

Laplacian field provides point location and

interpolation capabilities that are far more efficient than those provided for the more general

curvilinear cases.

Object Interfaces: Generality and Specificity

The Field Model design strives for both generality and specificity. While at first it might seem as if the two goals would

be mutually exclusive, both can be achieved through a combination of standard interfaces and C++ templating techniques. FM achieves generality through common interfaces

for meshes and fields. The common interfaces in turn enable

increased code reuse. For example, many visualization and

analysis algorithms written in terms of FM work for both

single and multi-block meshes. Multi-block meshes are often

used when analyzing air flow in domains with complicated

shapes, such as that between a wing and flaps. In some cases

analysis techniques written in terms of FM also work with

both structured and unstructured meshes. 

The mesh interface provides iterators similar to those in the

C++ standard library. Using iterators, one can loop over the

cells of a mesh without regard to how the cells are represented internal to the mesh instance. Iterators further enhance

reuse. For example, an algorithm designed to iterate over the

vertices of a mesh can work with many different mesh types.

The majority of data access calls on FM objects occur

through virtual functions where the data are requested one

cell at a time. Compared to simply accessing data directly

from buffers in memory, the virtual function approach

comes with a minor increase in processing time. However,

the virtual function interface enables the data model to handle many cases where the simpler approach would not be

feasible. For example, in cases where the data are much

www.nas.nasa.gov/gridpoints Gridpoints 11

Figure 3, left, and Figure 4,

below, illustrate two different

visualizations based on the same

data of a vitamin B-12 molecule. Figure 3 is a traditional

ball and stick figure with a slice

plane colored by the Laplacian

field, while Figure 4 is a volume

rendering of the same field. 

The gray atom sliced by the cutting plane in Figure 3 is cobalt.

The same atom is visible as a

cyan sphere in the middle of

Figure 4. (Figure 3: Patrick

Moran; Figure 4: Chris Henze)

Figure 3

Figure 4
larger than main memory, more sophisticated techniques

are required. 

Demand Driven: When Laziness Is a Virtue

In the analysis of simulation results, scientists are often interested in values derived from the fundamental state variables.

For example, they might be interested in velocity or vorticity values derived from the density and momentum fields

output during a simulation. The approach used by older

analysis tools is to compute and save the derived value over

the entire field. This approach, however, can be very wasteful: in many cases the derived values are only needed on a

surface, or along the path of a streamline. 

A more effective approach is to compute the derived values

only as needed, avoiding unused computations and saving

on memory requirements. Such an approach is known as

“demand-driven” or “lazy” evaluation. FM includes classes

that provide lazy derived field capability. The virtual function interface of FM enables one to use lazy fields interchangeably with other types of fields, transparent to the routines accessing the data.

The lazy evaluation aspects of FM are also key to working in

concert with out-of-core paging techniques. The memory

requirements of eager derived fields – the opposite of lazy –

would defeat the memory saving advantages of paging. With

large time-series datasets in particular, it is essential that the

data model have a consistent, effective strategy for memory

management. In the future, NAS researchers will adapt the

paging code in FEL to the FM design (see “How a New

Algorithm Powers Unsteady Flow Visualization,” Gridpoints,

Summer 2001).

An Open Source Approach

FM is just one component in a larger framework development effort whose focus is interactive scientific visualization

and analysis. For this effort to be a success, researchers must

consider not only design issues, but also the approach to software development. For FM, the decision was made to adopt

12 Gridpoints

Figure 5: Example meshes, organized by B and D values. In

FM, meshes are templated by two integer parameters: B and D.

The parameter B specifies the intrinsic dimensionality of the

mesh shape, for example 2 for a surface, 3 for a “volume” mesh.

The D parameter specifies the dimensionality of the space that

the mesh is embedded in. An image object, for example, would

have B and D equal to 2. An isosurface in 3-D would have B

equal to 2 and D equal to 3. A hexahedral mesh in 3-D would

have B and D equal to 3. Note that a wide variety of meshes can

share the same templated interface, including scattered vertex

meshes and molecular “stick figure” meshes. In many instances,

researchers need mesh interfaces or field interfaces that are conceptually the same, but differ by specific types. For example,

meshes in 2-D and 3-D have much the same interface, but differ in the number of coordinates passed as arguments. Similarly,

fields all share the same basic interface, though various instances

can differ by node type, for example, various scalar types (C++

captures this concept of parameterized classes through a mechanism known as templates.) (Patrick Moran)
an open source strategy. With open source software, programmers have access to the source code, enabling them to

understand how the software operates. This understanding

in turn allows users to contribute bug fixes and extensions,

improving the quality of the software in the long run.

A data model is not a stand-alone application; rather, it is just

one software component intended to serve within much larger scientific frameworks. Since the software is not self-contained, it does not lend itself to a traditional software distribution approach where ready-to-execute binary code is all

that is made available. On the contrary, users need to be able

to see inside the code to understand how it works to determine how it can fit within their own design. Furthermore, if

other research groups are to seriously consider utilizing a

component within their own software projects, there must be

some assurance that licensing requirements will not require

removing that component at a later time. 

Working with the NASA Ames Commercial Technology

Office, NAS Division researchers have established Field

Model as an open source effort, based at the SourceForge

software development website (see What is Open Source?).

SourceForge is home to a vast number of open source software efforts, including projects sponsored by other government agencies, such as the Department of Energy. By

embracing an open approach, the NAS Division is seeking

the high-end computing community’s participation and contributions. The HDF-EOS module is just one initial example of such a joint effort. Collaboration efforts are key to the

success of computational science grids. 

Patrick Moran is co-lead of the data analysis group within the

Research Branch of the NAS Division. He joined NASA after

receiving his doctorate in computer science from the University

of Illinois at Urbana-Champaign in 1996. While at the

University of Illinois he was a research assistant

with the National Center for Supercomputing

Applications (NCSA), where he developed highperformance biological imaging applications.

His research interests include graphics, scientific

visualization, and computational geometry.

www.nas.nasa.gov/gridpoints Gridpoints 13

“Open source” is a designation for software intended to be

distributed with source code openly available. There are a

variety of licenses that have been endorsed by the Open

Source Initiative as appropriate for open source distributions. The endorsed licenses are similar in that they all allow

for open distribution of the initial software and redistribution of the software in modified form. The licenses also differ in crucial ways. In particular, some allow redistribution

in proprietary form, while others require that all modifications remain open. Determining which requirements are

essential is a topic that is still debated by industry, academia, programmers, and end users.

There are several open source efforts that are particularly

relevant to high-end computing, including the GNU g++

compiler, the Python and Perl programming languages, and

the GNU/Linux operating system. Among scientific visualization tools, some of the leading systems are open source,

including the Visualization Toolkit (vtk) and OpenDX

(formerly IBM Data Explorer). The growing importance of

open source for high-end computing prompted the federal

government to recently seek guidance on the topic. 

A panel titled “Developing Open Source Software to Advance High End Computing” was convened by the

President’s Information Technology Advisory Committee

(PITAC). Participants included representatives from academia, industry, and government laboratories. NASA representatives included Bill Feiereisen, chief of the NASA

Advanced Supercomputing Division. The lead recommendation produced by the panel states, “The federal government should encourage the development of open source

software as an alternate path for software development for

high-end computing.” Open source software has also been

endorsed by several of the traditional vendors of high-performance computing systems, including IBM. Other information technology vendors, notably Microsoft, have argued

against open source and have offered more restrictive alternatives such as “shared source” in its place.

Learn More

For additional information on Field Model, Open Source,

and scientific visualization, visit:

• Field Model site: http://field-model.sourceforge.net/

• Field Model: An Object-Oriented Data Model

for Fields, technical report NAS-01-005.

www.nas.nasa.gov/Research/Reports/techreports.html

• Open Source Initiative http://opensource.org/ 

• T. Sandstrom and N. Chaderjian. “The Power of Unsteady Flow Visualization.” Gridpoints, Summer 2001

www.nas.nasa.gov/gridpoints

• The FEL 2.2 User Guide: technical report NAS-00-002.

www.nas.nasa.gov/Research/Reports/techreports.html

• PITAC report: 

www.itrd.gov/pubs/pitac/pres-oss-11sep00.pdf 

• Free Software Foundation: www.fsf.org

What Is Open Source?
When it rains in San Francisco or snows in Chicago, air traffic will be delayed. The Federal Aviation Administration (FAA) limits aircraft from flying closer than 4,300 feet to one another during the landing

phase when visibility is restricted. San Francisco International Airport (SFO), for example, is unfortunately unique

in that its runways are not only parallel, but are spaced only

750 feet apart. As soon as bad weather limits visibility at

SFO, one of the parallel runways is closed. Runway closure

reduces the airport’s capacity from 95 to 99 flights per hour

down to between 67 and 72 flights per hour. Depending on

the length of the delay in the landing cycle, aircraft at distant

airports bound for SFO are in turn prevented from taking

off, as they will not have a place to land. Bad weather delays

cause back-ups across the entire air traffic system.

NASA is constantly working to improve the air traffic system’s capacity. The agency has been developing the Aircraft

Vortex Spacing System (AVOSS) that will provide new

guidelines for aircraft separation in bad weather, real-time

simulations of aircraft wakes, and jetliner wake sensing and

tracking. The current wake sensing and tracking components

of AVOSS, however, are unable to meet the system’s requirements in haze, fog, or heavy rain. Wakes are dangerous to following aircraft, and flight into a large aircraft’s wake has

proven fatal for many small aircraft.

To overcome the system’s shortcomings in bad weather,

Karim Shariff of the NAS Division’s Physics Simulation and

Modeling Office has filed a patent detailing a concept for

sensing wakes. Shariff’s research examines the interaction

between large jetliners and the turbulent wakes they leave

behind as they approach an airport for landing. Shariff

believes that if aircraft wakes can be monitored, and detailed information about the behavior of each aircraft’s

wake can be provided to air traffic controllers, jetliner separations can be reduced, enabling more landings per hour in

bad weather. 

Aircraft Separation In Flight

Flight in meteorological conditions of poor visibility, such as

fog, clouds, rain, or snow is known as IFR (Instrument Flight

Rules). During IFR flight, pilots rely on their instruments for

cues that normally come from looking out the window; for

example, the aircraft’s attitude in relationship to the horizon.

Pilots also receive information from air traffic controllers informing them where they are in relation to other aircraft, and

when to speed up or slow down during approach. Increasing

or decreasing speed maintains proper spacing distances between aircraft as they near runway touch down.

Vortices are created whenever lift is generated. They are

stronger when an aircraft is flying slower, and closer to the

ground. When an aircraft is descending in the landing configuration – flaps deployed and landing gear down, vortices

are generated as the aircraft passes through the air. The vortices combine to form a turbulent wake in the aircraft’s path.

Slowly, the wake descends out of the flight path and eventually dissipates. If one aircraft flies too close behind another, it

will encounter the preceding jetliner’s wake. 

Flying through the turbulence of another aircraft’s wake can

cause conditions from severe buffeting – which lasts until the

turbulence passes – to a loss of control. For this reason, aircraft are classified in three categories: small aircraft (less than

41,000 pounds gross takeoff weight – gtw); large aircraft,

such as the Boeing 737 or DC-8 (greater than 41,000

pounds gtw); and heavy jets, such as the Boeing 747 (greater

than 255,000 pounds gtw). The Boeing 757’s wake turbulence is extremely strong, and although the aircraft does not

meet the weight requirements to be designated as “heavy,” it

is classified as such for wake turbulence separations.

Having determined the dangers of following a large aircraft

too closely, the FAA established a number of safety guidelines. FAA separation guidelines are applied to an aircraft

flying directly behind or less than 1,000 feet below another

craft as follows: “heavy jet behind a heavy jet – 4 nautical

miles; large or heavy behind a Boeing 757 – 4 nautical miles;

small behind a 757 – 5 nautical miles; small or large behind

a heavy jet – 5 nautical miles.” When an aircraft approaches

the landing threshold, small aircraft are required to maintain

a 6-nautical-mile separation behind a heavy jet.

14 Gridpoints

Air Traffic Control Through

Wake Vortex Management

Theories advanced by the NAS Division’s Physics Simulation and Modeling

Office will increase airport capacity by reducing aircraft spacing in bad weather.
Many researchers and experts in the airline industry believe

the FAA-mandated separations are too conservative. The

FAA believes: “$5 billion could be saved annually by the airlines if one could safely reduce the current separations by 1

nautical mile.” Aside from the financial gains, flights would be

safer, and passengers would arrive at their destination sooner.

Today’s Wake Vortex Tracking

NASA currently uses LIDAR (LIght Detection And Ranging), a laser-based device that sends an infrared beam into

the wake of an aircraft for wake detection. Naturally occurring aerosol particles scatter the beam back to the device,

which is able to determine the position and speed of the particles. LIDAR, considered a first-generation vortex detector,

has a number of drawbacks when viewed as a potential fieldinstalled system: infrared particles are absorbed in water

vapor, rendering the system inoperative during foul weather;

and as an optical system, it requires a high amount of maintenance, including cleaning and replacement of optical parts;

and it is expensive to acquire and operate.

LIDAR was tested in Memphis, and has subsequently been

installed at Dallas/Ft. Worth International Airport. The system has proven that it can measure aircraft wakes and determine velocity profiles. The continuous wave LIDAR has a

range of only 900 feet – inadequate for a production system –

and the high-power pulse LIDAR is only capable of detecting vortices out to 2.5 miles in clear weather. LIDAR’s success will hopefully convince the FAA that the concept is

viable, which will enable NASA to secure funding to develop

a next-generation system.

Patenting A Theory

Shariff’s theory suggests that radar is a feasible next-generation wake detection system. Using radar, rather than an optical system, to detect wakes gives an all-weather capability.

“Radar scattering analysis revealed that peak reflectivity from

a trailing vortex occurs at a frequency near 50 megahertz

(MHz) (see Figure 1), and is strong enough that a vortex

could be detected at a 3 kilometer range with an average

power of about 400 watts,” says Shariff. “A frequency of 50

MHz has several advantages: Clutter from rain and fog is not

an issue and so the system would work in all types of weather; inexpensive and low-maintenance radars already operate

at 50 MHz for measuring atmospheric winds, and they could

be modified to track vortices; and, if the system is supplemented with sound waves to enhance reflectivity, the

required sound frequency is low enough that attenuation of

the sound wave (which would limit range) is not a problem.” 

www.nas.nasa.gov/gridpoints Gridpoints 15

Graphic representation of wing tip vortices as a U.S. Air Force Boeing C-17 airlifter flies through smoke. The aircraft’s vortices pull

the smoke inward as they wrap around each other. The C-17 is in the same “heavy” class as the Boeing 747 jumbo jet. (Boeing)

Wake Vortices

Figure 1: Predicted radar cross-section (RCS) of aircraft vortices. The symbols show the results of a scattering analysis implemented computationally. The curves show the results of a simple

but approximate analytical formula. Solid line and circle symbol: Vortex RCS for heavy class (Boeing 747) aircraft. Dotted

line and square symbol: Vortex RCS for a large class (DC-8)

aircraft. This figure is for a range of 1 kilometer.

(Karim Shariff)
Based on this theory, Shariff has filed a provisional patent

that states wing tip vortices can be detected at 50 Mhz by

making modifications to existing ST radars (Stratospheric,

Tropospheric; such radars are used for atmospheric physics).

“It’s a unique patent in the sense that it claims that such

devices exist already, and that with some modification they

can be used for a different application,” Shariff explains. “It’s

not that I have a new device, it’s more of a concept. That’s

why there was some reluctance about patenting it given that

it is another application of an existing device. But given that

it is another application of an existing device, and given

that it needs to be modified, hopefully they’ll give the final

patent and then I can say how one would go about modifying it.”

In an implementation of the radar device, air traffic controllers would be able to view data from the 50 Mhz radar,

detect the position of the vortices of landing aircraft, and

then inform trailing aircraft whether they should speed up or

maintain current spacing. The 50-Mhz radar would use

approximately 30 Yagi-type directional antennas (a pair of

dipoles, a parallel reflector, and a set of directors) arranged in

a “farm” near the end of a runway.

Putting the Theory to the Test

Shariff plans to put his theory to the test at Vandenburg Air

Force Base, California, within the next year. The U.S. Air

Force has built an Airborne Laser for use in destroying

Scud-type, tactical theater missiles during the boost

phase. The Airborne Laser has been mounted into a 747-

400 freighter that will orbit over battlefields and destroy

missiles as they ascend. 

The Air Force plans to test the Airborne Laser over the

atmospheric radar range at Vandenburg. “They will be looking at the deflections of this airborne laser beam due to

atmospheric turbulence. And then they’ll compare the data

with measurements on atmospheric turbulence they get from

the Vandenburg radar and use that to correct the beam’s

path,” Shariff says. “I’ve asked them if I can do a test in the

wake as the aircraft flies past this radar. The atmospheric

radar is exactly the same frequency as my predicted 50 Mhz. 

Shariff has received approval to run his experiment in concert

with the Air Force program. Once he obtains the test results

from Vandenberg and has his patent in hand, Shariff will

begin developing the system, which will require analyzing

wakes of other aircraft classes in a variety of weather conditions. The size of the radar’s antenna farm, and the beam’s

coverage of a typical landing approach path will also have to

be determined. Once developed into a field deployable system, NASA will transfer the technology to industry.

“We’re pursuing this research because building more airports

is not really an option,” Shariff says. “Environmental issues,

such as noise pollution and habitat encroachment, as well as

real estate costs, make building new airports prohibitive. It is

making use of wasted airspace, and it’s wasted because of

these vortices.”

— Nicholas A. Veronico

16 Gridpoints

NASA’s Langley Research Center performed a number of wake vortex studies at its Wallops Island facility. A crop duster was flown

low and slow over a red smoke flare. As the wing tip passed over the smoke generator, the vortices created a turbulent flow that can

cause control problems to following aircraft. (NASA)
Calendar of

Events

Ninth Foresight Conference on

Molecular Nanotechnology

Santa Clara, California • November 9–11

The Ninth Foresight Conference on Molecular Nanotechnology will be held at the Westin Hotel in Santa Clara,

California to provide a forum for leaders from all areas of science and technology involved in research at the nanoscale to

present and discuss their most recent results and ideas. Visit:

www.foresight.org/Conferences/MNT9/index.html 

SC2001

Denver, Colorado • November 10–16 

SC2001 will bring together scientists, engineers, designers,

and managers from all areas of high-performance networking and computing, and showcase the latest in systems,

applications, and services. The conference website is:

www.sc2001.org

2001 Information Power Grid Workshop

Palo Alto, California • December 5–6

This year’s workshop will be held at the Crowne Plaza

Cabana Hotel, in Palo Alto, California, to focus on IPGrelated grid technology. Presentations will include talks from

research and development teams from each of the major

IPG-related organizations including: NASA centers; Argonne National Laboratory; NCSA; San Diego Supercomputer Center; USC’s Information Sciences Institute, and

other participating universities. Papers in several areas are

being solicited for presentation and discussion at the workshop. Advance registration is required. For the latest information, visit: www.ipg.nasa.gov or NAS’s technical training

site: www.nas.nasa.gov/User/Trainng/training.html. For

more information, contact: Marcia Redmond, mredmond@

mail.arc.nasa.gov.

Global Grid Forum (GGF) Four

Toronto, Canada • February 17–20 

The fourth Global Grid Forum provides working and educational sessions for researchers and those interested in grids

and grid technologies. Agenda and details are coming soon

to: www.gridforum.org

IEEE Virtual Reality 2002

Orlando, Florida • March 24–28

Research and technology exhibition showcasing virtual reality software, hardware, and systems development. The seventh annual Immersive Projection Technology Symposium

will be held inconjunction with the virtual reality exhibition.

Additional details are available at: www.VR2002.org 

IEEE Symposium on Mass Storage Systems

Adelphi, Maryland • April 15–18

The 19th IEEE Symposium on Mass Storage will be held in

cooperation with the 10th NASA Goddard Conference on

Mass Storage Systems and Technologies at the Inn and

Conference Center at the University of Maryland to provide

a forum for discussion of issues relevant to the management

of large volumes of data. For more information visit

http://storageconference.org/2002

International Parallel and Distributed

Processing Symposium

Ft. Lauderdale, Florida • April 15–19

The International Parallel and Distributed Processing

Symposium (IPPS/SPDP) is designed for scientists and engineers from around the world to present their research and

discoveries in all aspects of parallel computation. The symposium will include technical sessions, workshops, tutorials,

and commercial exhibits. For conference information, visit:

www.ipdps.org

Siggraph 2002

San Antonio, Texas • July 21–26

The 29th International Conference of Computer Graphics

and Interactive Techniques is a forum for computer graphics

scientists, artists, engineers, and educators. Technical presentations will include papers, panels, courses, applications, an

educators program, web graphics program, and an applications lab. Conference information can be viewed at:

www.siggraph.org/s2002

www.nas.nasa.gov/gridpoints Gridpoints 17

NAS Division researchers have developed a parallel and distributed computing (PDC) tool for large-scale unsteady moving

body applications using overset structured grids. The V-22 simulation is a large-scale Navier-Stokes problem consisting of a

moving body grid system of approximately 37 million points. A

performance assessment of the PDC tool indicates that this

application can be run on wide area networks such as NASA’s

Information Power Grid. (Jahed Djomehri)
FIRST CLASS MAIL

POSTAGE & FEES PAID

NASA

Permit No. G-27

National Aeronautics and Space Administration

NASA Advanced Supercomputing Division

Ames Research Center

MS 258-6

Moffett Field, CA 94035-1000

Official Business

Penalty for Private Use $300

Address Correction

if the above address or mail stop is incorrect, please e-mail a current 

address to gridpoints@nas.nasa.gov, or write to:

Gridpoints Editor, MS 258-6, Moffett Field, CA 94035

PLEASE RECYCLE

Printed on recycled and recyclable paper with vegetable-based inks

MESOSPHERE

STRATOSPHERE

POSPH

(D) Heat trapped by 

Greenhouse gases 

(B) Earth emits 

blackbody 

radiation

(E) Infrared radiation 

absorbed by GHGs

(A) Sunlight 

Reaches Earth

Greenhouse Gases 

(GHGs) nearly 

transparent to 

sunlight

(C) Some radiation 

escapes to space through the 

"atmospheric window"

Solving The Cancer Equation

A visiting professor at the NAS Division believes the key to

winning the war against breast cancer is using partial differential equations to model the spread of cancer in individuals. See page 4.

The Heat is on . . . Earth

Computational Chemistry is being used to calculate the

level of toxicity of industrial compounds being released into

the Earth’s atmosphere, which are contributing to a rise in

global surface temperatures. See page 6.

Blood Vessel

Red Blood Cells

Lymphocytes