Reference Guide

v. 1.0

www.nasa.gov | #Artemis

National Aeronautics and Space Administration

ARTEMIS
Contents

ARTEMIS REFERENCE GUIDE

Contents

Foreword v

Purpose vi

Introduction 1

Artemis Overview 2

Artemis I 3

Artemis II and Beyond 4

Space Launch System (SLS) 5

Introduction 6

Overview 7

Future Missions and Configurations 7

Elements 10

Core Stage 10

Solid Rocket Boosters 14

Interim Cryogenic Propulsion Stage 14

Launch Vehicle Stage Adapter 15

Orion Stage Adapter 15

Avionics and Software 15

Testing 17

RS-25 Engine Testing 17

Booster Testing 18

Core Stage Green Run Testing 18

Structural Testing 18

Wind Tunnel Testing 19

Management Roles and Facilities 20

NASA Centers 22

Partners 23

Quick Facts 24

Super Heavy Lifting on the Ground: 

Transportation, Logistics, and 

Pathfinders 24

Orion Spacecraft 27

Introduction 28

Overview 29

Future Missions and Configurations 29

Elements 30

Crew Module 30

European Service Module 33

Launch Abort System 36

Avionics and Software 37

Parachutes 42

Crew Module Uprighting System 43

Testing 43

Exploration Flight Test-1 44

Heat Shield Testing 45

European Service Module Propulsion Testing 45

Acceptance Testing 45

Environmental Testing 46

Structural Testing 47

Launch Abort System Testing 48

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Aerodynamic, Aerothermal, and 

Aeroacoustics Testing 49

Parachute Testing 49

Crew Module Uprighting System Testing 50

Water Impact Testing 50

Avionics and Software Testing 50

Flight Control Team Training and Testing 51

Management Roles and Facilities 52

Armstrong Flight Research Center 52

Goddard Space Flight Center 52

Jet Propulsion Laboratory 52

Johnson Space Center 52

Kennedy Space Center 53

Marshall Space Flight Center 53

Langley Research Center 53

Glenn Research Center 53

Ames Research Center 54

Industry and International Partners 54

Quick Facts 55

SLS and Orion Livery and External 

Markings 57

Livery and Photogrammetric Markings 58

Cameras 58

Exploration Ground Systems 60

Introduction 61

Overview 62

Future Missions and Configurations 62

Elements 63

Launch Complex 39 63

Vehicle Assembly Building 63

Launch Pad 39B 65

Launch Pad Systems and Elements 66

Mobile Launcher 67

Crawler-Transporter 69

Crawlerway 69

Software 70

Recovery Operations 71

Testing 72

Integrated Test and Checkout Tests 

to Prepare for Flight 72

Crawler-Transporter 2 Testing 73

Sound Suppression Testing 73

Underway Recovery Testing 74

Launch Simulations 74

Management Roles and Facilities 74

Kennedy Space Center 74

Industry Partners 76

Quick Facts 77

Space Communication and 

Navigation Systems 79

NASA’s Near Space Network 80

NASA’s Deep Space Network 80

Acronym List 81

Image credit: NASA

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Image credit: NASA

iv
Foreword

ARTEMIS REFERENCE GUIDE

Jim Free, Associate Administrator

Exploration Systems Development Mission Directorate (ESDMD)

The launch of Artemis I marks a proud and powerful 

moment in NASA’s and the nation’s history. This flight 

test is the result of an unparalleled workforce, tireless engineering, advances in modern fabrication and computing, 

strong industry and international partnerships, and vital 

support from Congress and multiple administrations. The 

path to Artemis I has continued through historic events, 

including the global pandemic and devastating storms 

that broke records in both number and magnitude. Yet 

here we are, ready to launch!

We are at the culmination of thousands of tests and 

analyses conducted across the country and beyond. Like 

many firsts in engineering on this scale, particularly for 

human space exploration vehicles, the rigors of analysis 

and testing cannot be fast-tracked or minimized. It is 

humbling that even our best modeling and simulations 

need operational validation. We learn something, at some 

level, every time we test.

We will launch the world’s only spacecraft designed to 

carry humans to deep space, atop the most powerful 

rocket, with our dedicated ground systems team and 

launch and mission control personnel. We’ll take what we 

learn from Artemis I and apply these lessons as we move 

further on the path of human exploration.

We have so many to thank for reaching this tremendous 

milestone, not only our tireless industry and international 

partners, but—perhaps most importantly—we thank our 

families, who have supported us on this quest to explore 

the cosmos that will begin at Launch Pad 39B.

In addition to the contributions from our primary industry contractors and international partners, thousands of 

companies across all 50 states have contributed to building 

these systems. Their contributions strengthen our national 

aerospace capabilities and return economic benefits to 

their communities. 

To the Artemis I team: Please take in every moment of 

the mission, from rollout and launch to splashdown, and 

all the moments in between. Pause to reflect on all that 

we’ve achieved together. Acknowledge your individual 

and team contributions to this great mission.

This Artemis Reference Guide is a look into all the parts 

that have come together to reach Artemis I, the mission 

that signals the beginning of our human return to the 

Moon. I hope you will take time to peruse this document 

along with all the other resources available online and 

appreciate the immense energy and effort that brought us 

to this moment.

It’s time to fly!

Jim

A sunrise view of the low bay entrance to the Vehicle Assembly Building 

(VAB) at NASA’s Kennedy Space Center in Florida on Jan. 19, 2022.

Foreword

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Purpose

Under Artemis, the new era of lunar exploration, NASA and its partners will lead humanity forward to the Moon and prepare us for the next giant leap, human exploration of 

Mars. This Artemis Reference Guide provides detailed descriptions of the systems 

and subsystems pertaining to the Artemis I mission, including program overviews; 

technical elements; testing; and management roles and facilities for the Space Launch 

System (SLS) rocket, Orion spacecraft, and associated ground systems.

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Introduction

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Artemis Overview

We’re going back to the Moon for the benefit of all 

humanity—scientific discovery, economic benefits, and 

inspiration for a new generation of explorers: the Artemis 

Generation. While maintaining American leadership in 

exploration, we will build a global alliance and explore 

deep space as one. With Artemis missions, NASA will 

land the first woman and first person of color on the 

Moon, using innovative technologies to explore more of 

the lunar surface than ever before. We will collaborate 

with commercial and international partners and establish 

the first long-term presence on the Moon. Then, we will 

use what we learn on and around the Moon to take the 

next giant leap: sending the first astronauts to Mars.

America has entered a 

new era of exploration. 

We call it Artemis.

 Astronauts Stephanie Wilson, Karen Nyberg, and Rick Mastracchio (left to right) assist in testing the docking hatch on a representative model of the Orion 

spacecraft at Johnson Space Center. Image credit: NASA

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Artemis I

Artemis I will be the first integrated flight test of NASA’s 

deep space exploration systems: the Orion spacecraft, the 

Space Launch System (SLS) rocket, and the supporting 

ground systems at NASA’s Kennedy Space Center in 

Florida. The first in a series of increasingly complex missions, Artemis I will provide a foundation for human deep 

space exploration and demonstrate our commitment and 

capability to extend human presence to the Moon and 

beyond. The primary goal of Artemis I is to thoroughly 

test the integrated systems before crewed missions by 

launching Orion atop the SLS rocket, operating the 

spacecraft in a deep space environment, testing Orion’s 

heat shield, and recovering the crew module after reentry, 

descent, and splashdown.

The SLS rocket will launch an uncrewed Orion spacecraft 

from Launch Complex 39B at NASA’s modernized spaceport at Kennedy. As the Orion spacecraft orbits Earth, 

it will deploy its solar arrays, and the interim cryogenic 

propulsion stage (ICPS) will give Orion the big push—

called a trans-lunar injection—needed to leave Earth’s 

orbit and travel toward the Moon. From there, Orion will 

separate from the ICPS about two hours after launch. 

After Orion separates from the ICPS, 10 small satellites 

known as CubeSats will be deployed to perform experiments and technology demonstrations. The CubeSats will 

conduct a range of investigations and technology demonstrations from studying the Moon or an asteroid to the 

deep space radiation environment. Each CubeSat provides 

its own propulsion and navigation to get to various deep 

space destinations.

Orion will continue on a path toward a lunar distant 

retrograde orbit, where it will travel about 40,000 miles 

beyond the Moon, or a total of about 280,000 miles from 

Earth, before returning home. This flight test will demonstrate the performance of the SLS rocket on its maiden 

flight and gather engineering data throughout the journey 

before Orion returns on a high-speed Earth reentry at 

speeds of more than 25,000 mph. The high-speed lunar 

velocity reentry is the top mission priority and a necessary 

test of Orion’s heat shield performance as it enters Earth’s 

atmosphere, heating to nearly 5,000 degrees Fahrenheit 

(2,760 degrees Celsius)—about half as hot as the surface 

of the Sun—before splashing down in the Pacific Ocean 

for retrieval and post-flight engineering assessment.

 Illustration of the Orion spacecraft returning to Earth. Image credit: NASA

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Artemis II and 

Beyond

The Artemis II flight test will be NASA’s first mission with 

crew aboard Orion and will confirm that all the spacecraft’s systems operate as designed with humans aboard 

in the deep space environment. The initial launch will be 

similar to that of Artemis I as SLS lofts Orion into space. 

With a crew of four astronauts aboard this mission, Orion 

and the ICPS will orbit Earth twice before committing to 

the trip to the Moon to ensure that Orion’s systems are 

working as expected while still close to home.

After Orion separates from the ICPS, the crew will use 

it as a target for a proximity operations demonstration. 

The crew will use Orion’s onboard cameras and the view 

from the spacecraft’s windows to line up with the ICPS 

as they approach and back away from the stage to assess 

Orion’s handling qualities and related hardware and software. This demonstration will provide performance data 

and operational experience that cannot be readily gained 

on the ground in preparation for rendezvous, proximity 

operations, and docking, as well as undocking operations 

in lunar orbit beginning on Artemis III.

Following Artemis I and II, Artemis III will see Orion and 

a crew of four once again travel to the Moon, this time to 

make history by landing the first 21st-century astronauts 

on the lunar surface. Beginning with Artemis III, NASA 

intends to launch crewed missions about once per year, 

with initial missions focused on establishing surface capabilities and building Gateway, an outpost in orbit around 

the Moon that will provide access to more of the lunar 

surface than ever before.

NASA astronaut Nicole Mann gives a thumbs-up from inside the Orion 

mockup. Image credit: NASA/Bill Ingalls

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Space Launch 

System

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Introduction

SLS is a super-heavy-lift rocket that provides the foundation for human exploration beyond Earth’s orbit. NASA 

evaluated thousands of combinations of attributes such 

as propulsion systems, stages, boosters, performance, 

development and operations cost, mission complexity, 

reliability and risks, and the ability to maintain industry 

base skills. The result was an evolvable rocket, available in 

crew or cargo configurations, with a proven propulsion 

system, that provides a safe launch capability for human 

exploration to deep space—the SLS rocket.

SLS was designed for the most challenging deep space 

missions involving strategic commitments of national 

resources, national prestige, and human life. SLS 

The SLS rocket for Artemis I stands inside 

High Bay 3 of the Vehicle Assembly Building at 

NASA’s Kennedy Space Center in Florida. 

Image credit: NASA

SLS is the 

world’s most 

powerful rocket 

and the backbone 

of NASA’s human 

lunar exploration 

program.

HELPFUL RESOURCES

For more information about SLS, visit 

https://www.nasa.gov/sls

SOCIAL MEDIA

Twitter: https://www.twitter.com/NASA_SLS

Facebook: https://www.facebook.com/NASASLS

Instagram: https://www.instagram.com/NASAArtemis

represents the best balance of mission performance, safety, 

cost, affordability, and risk. SLS is also designed to be flexible and evolvable, opening new possibilities for payloads, 

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including robotic scientific missions to places like the 

Moon, Mars, and beyond. With its unprecedented power 

and capabilities, SLS has the largest payload mass and volume of any existing rocket and is the only rocket that can 

safely send Orion, astronauts, and cargo to the Moon on a 

single mission. More mass and volume translate into fewer 

launches of fewer pieces, requiring less assembly time in 

space and less overall risk.

Overview

SLS is designed for deep space missions and will send the 

Orion spacecraft and cargo to the Moon, which is nearly 

1,000 times farther than where the International Space 

Station resides in low-Earth orbit. The rocket will provide 

the power to help Orion reach a speed of 22,600 mph, the 

speed needed to send it to the Moon.

SLS benefits from over 50 years of NASA experience with 

liquid oxygen and liquid hydrogen propellants, along with 

advances in technology and manufacturing practices. SLS 

development and manufacturing operations take advantage of resources established for the space shuttle, including the workforce, manufacturing processes, tooling and 

facilities, transportation logistics, launch infrastructure, 

and liquid oxygen and liquid hydrogen propellants.

SLS evolvability supports robust human exploration 

beyond low-Earth orbit as exploration missions become 

more complex and demanding. All planned variants of 

the basic SLS design are based on common propulsion 

components:

• A central core stage housing propellant tanks, engines, 

avionics, and attach points for a pair of solid rocket 

boosters.

• Four liquid propellant RS-25 engines powered by 

cryogenic, or supercold, liquid hydrogen and cryogenic 

liquid oxygen from the core stage.

• Two solid-fuel, side-mounted booster motors that provide the majority of thrust and steering for the rocket 

during the first two minutes of flight, after which they 

are jettisoned.

• An upper stage fueled by liquid hydrogen and liquid 

oxygen for in-space propulsion after separation from 

the core stage.

Future Missions and Configurations

To fulfill America’s future needs for deep space missions, 

SLS will evolve into increasingly more powerful configurations. Each succeeding SLS block variant grows more 

capable through upgrades to the engines, boosters, and 

upper stage, providing a flexible platform for a variety 

of human and robotic deep space missions, rather than 

requiring the development of entirely new rockets to 

increase performance. SLS uses common design elements 

that can interface with the ground systems at Kennedy, 

the Orion spacecraft, and future payloads, reducing 

the complexity of deep space missions over time. In 

addition to flying Orion, SLS can also be outfitted with 

wide-diameter payload fairings in varying lengths for 

cargo and robotic science missions.

The Artemis I mission will use the first configuration of 

the SLS rocket, known as Block 1, capable of lifting more 

than 59,500 pounds (27 metric tons) to orbits beyond 

the Moon. The Block 1B variant will follow the Block 1 

configuration beginning with Artemis IV and will be 

able to lift more than 83,000 pounds (38 metric tons) to 

deep space, including Orion and its crew. The Block 1B 

variant incorporates several upgrades to improve SLS 

performance, allowing the rocket to launch larger and 

heavier payloads to deep space destinations. SLS Block 1B 

uses the same core stage and twin five-segment solid 

rocket boosters as the Block 1 rocket. New-production 

RS-25 engines will provide slightly more thrust than the 

shuttle-era engines and cost 30 percent less to manufacture. Most of the increase in performance for the Block 1B 

rocket will come from replacing the single-engine ICPS 

with a more powerful four-engine exploration upper stage 

and a universal stage adapter to carry Orion along with 

large cargos for exploration systems needed to support a 

long-term presence at the Moon.

The Block 2 variant retains the core stage, RS-25 engines, 

and the new upper stage, but replaces the Block 1 steel case 

booster motor design with a lighter composite case, new 

propellant formulation, and other upgrades that increase 

overall performance. It will provide 9.5 million pounds of 

thrust and lift more than 101,000 pounds to the Moon 

and more than 80,000 pounds to Mars.

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Elements

Core Stage

The SLS core stage is the tallest and most powerful rocket 

stage NASA has ever built. It measures approximately 

212 feet tall and 27.6 feet in diameter (excluding thermal protection system foam and flanges). The stage is 

the largest ever built by length and volume, and its fully 

fueled weight, excluding engines, is 2.4 million pounds. 

It was manufactured by the lead contractor for the core 

stage, Boeing, at NASA’s Michoud Assembly Facility in 

New Orleans using state-of-the-art manufacturing equipment. Michoud is a unique advanced manufacturing 

facility where NASA has built spacecraft components for 

decades, including the space shuttle’s external tanks and 

Saturn rockets.

The SLS core stage is designed to operate for the roughly 

eight-minute Artemis I launch from ground and ascent to 

Earth orbit, reaching speeds of faster than 17,500 mph, or 

nearly 23 times the speed of sound (Mach 23), and more 

than 530,000 feet in altitude before it separates from the 

ICPS, Orion stage adapter, and Orion spacecraft.

The core stage was a major new development effort for 

the SLS Program, while other key elements, such as the 

RS-25 engines, solid rocket booster structures, and ICPS, 

Diagram of the main components of the Space Launch System. Image credit: NASA

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have a rich, reliable spaceflight history. Like other SLS 

components, the SLS core stage leverages design experience from the space shuttle and has the same diameter as 

the shuttle external tank, and the propellant feedlines and 

fill and drain ducts were sized around heritage joints and 

existing valves.

As the literal core of SLS, the core stage supports other 

stages, spacecraft, and payloads atop its uppermost section 

and serves as the attach point for the two solid rocket 

boosters. It also includes the four RS-25 main engines, 

their liquid hydrogen and liquid oxygen propellant supply, 

and the avionics and software that control SLS operation 

and flight until the core stage separates from the ICPS.

The core stage is made up of 10 major barrel sections, four 

dome sections, and seven rings. Each cylindrical barrel 

section consists of eight aluminum panels that vary in 

length and height depending on the section. Those panels 

are friction stir welded or bolted vertically and horizontally to form the five major sections of the core stage:

• Engine section

• Liquid hydrogen tank

• Intertank

• Liquid oxygen tank

• Forward skirt

Friction stir welding transforms the metals from a solid 

state into a “plastic-like” state and then mechanically stirs 

the materials together under pressure to form a welded 

joint, producing high-strength bonds virtually free of 

defects. The intertank is the lone bolted section; it provides 

added strength to carry booster loads.

Beginning at the bottom, or aft end, of the stage, the engine 

section houses four RS-25 main engines, the engine thrust 

structure, propellant ducts, various avionics systems, and 

engine thrust vector control systems; it also serves as the 

lower attach point for the two solid rocket boosters.

The engine section consists of a single barrel section with 

welded aluminum isogrid panels and is 27.6 feet in diameter and 22.5 feet long. Isogrid is a pattern milled into the 

barrel section panels that reduces weight while retaining 

structural strength. An aerodynamic boat tail fairing at 

the bottom channels airflow and protects the engines 

from extreme temperatures during launch.

The liquid hydrogen fuel tank is 27.6 feet in diameter and 

130.8 feet tall. It consists of five welded barrel sections, 

each 22 feet tall, and two end domes. The lower end of 

the liquid hydrogen tank includes four liquid hydrogen 

feedlines to the RS-25 engines. The tank has a capacity of 

537,000 gallons of liquid hydrogen at minus 423 degrees 

Fahrenheit (minus 253 degrees Celsius).

The intertank separates the upper dome of the liquid hydrogen tank from the lower dome of the liquid oxygen tank 

and serves as the forward attach point for the boosters. The 

intertank contains one barrel section and measures 27.6 feet 

The SLS core stage is shown atop the mobile launcher inside High Bay 3 

of the VAB at NASA’s Kennedy Space Center on June 12, 2021.

Image credit: NASA

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in diameter and 21.8 feet tall. It contains a thrust structure 

to carry loads imparted from the solid rocket boosters 

during ascent. The intertank also contains several avionics 

components, including two rear-facing cameras and interfaces to the liquid hydrogen and liquid oxygen tanks.

The liquid oxygen tank is 27.6 feet in diameter and 51.6 

feet tall. It consists of two barrel sections of isogrid aluminum panels and two domes. Liquid oxygen is fed to 

the engine section and engines through a pair of “downcomer” ducts that exit the intertank on opposite sides and 

run down the core stage. The liquid oxygen tank has a 

capacity of 196,000 gallons of liquid oxygen at minus 297 

degrees Fahrenheit (147 degrees Celsius).

The forward skirt is located at the top of the core stage. 

It contains one barrel section and connects the core stage 

to the launch vehicle stage adapter. The aluminum isogrid structure is 27.6 feet in diameter and 10.4 feet tall. 

It houses the majority of the rocket’s avionics and has 

connections to launch pad utility umbilicals, the vehicle 

stabilization system that helps secure SLS to the mobile 

launcher, access doors, vent system, pressurant lines, and 

communications antennas.

The main propulsion system in the core stage consists of 

the ducts, valves, and other equipment that supply and 

control the flow of liquid hydrogen and liquid oxygen 

propellants, as well as gaseous helium and nitrogen pressurants for valve actuation and line or volume purges. To 

accomplish those functions, the main propulsion system 

has four subsystems:

• Liquid oxygen

• Liquid hydrogen

• Pressurization

• Pneumatics supplied by ground systems prior to launch

Major drivers in the design of the main propulsion system 

included the main propellant tank configuration, main 

engine configuration, reliability and affordability, mission 

requirements, and component mounting. For instance, 

the main propulsion system flow rates and interfaces were 

designed around the RS-25 configuration and the need to 

supply propellants to the engines under temperature and 

pressure conditions required by the engines. The orientation of the engine hydrogen and oxygen feed lines in the 

engine section determined the feed system layout for the 

main propulsion system.

Teams with Exploration Ground Systems (EGS) and lead contractor Jacobs transport the massive SLS core stage to Kennedy Space Center’s 

Vehicle Assembly Building in Florida on April 29, 2021, after its journey from NASA’s Stennis Space Center in Mississippi aboard the Pegasus barge. 

Image credit: NASA

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HOW IT WORKS Combustion occurs when a fuel is 

combined with oxygen to produce energy to propel a 

vehicle. In automobiles, oxygen from the atmosphere 

combines with gasoline and an ignition source to run a 

combustion engine. In rocket science, propellants may 

include both fuel and a chemical oxidizer that releases 

oxygen. When the fuel and oxidizer combine, they 

ignite through a chemical reaction, and the hot, rapidly 

expanding gases look for a way out and move the 

rocket or spacecraft in the opposite direction.

Thermal Protection System

The orange color of the core stage is actually the thermal 

protection system, or spray-on foam insulation. This insulation, along with other materials such as cork, provides 

thermal protection for every part of the rocket, although it 

is most visible on the core stage. The insulation is flexible 

enough to move with the rocket but rigid enough to take 

the aerodynamic pressures as SLS accelerates from 0 to 

17,500 mph and soars to more than 100 miles above Earth 

in just 8 minutes.

Materials engineers qualified the third-generation, 

orange-colored spray-on foam insulation to meet the 

harsh environments that SLS will experience. At the 

same time, they made the foam more environmentally 

friendly. When the foam is applied, it gives the rocket a 

light-yellow color that the Sun’s ultraviolet rays eventually 

“tan,” giving the SLS core stage its signature orange color.

The thermal protection system provides the insulation 

to keep the cryogenic propellant that powers the RS-25 

engines extremely cold to remain liquid. If temperatures 

rise too high, the propellant will become a gas. Hydrogen 

must remain at minus 423 degrees Fahrenheit (minus 

253 degrees Celsius) and oxygen at minus 297 degrees 

Fahrenheit (minus 183 degrees Celsius).

Image credit: NASA

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All four RS-25 engines attached to the SLS core stage inside NASA’s Michoud Assembly Facility in New Orleans. Image credit: NASA

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RS-25 Engines

Four Aerojet Rocketdyne RS-25 engines are part of the 

engine section of the core stage and power the core stage 

of SLS. Formerly known as the Space Shuttle Main 

Engine, the RS-25 has successfully flown on 135 shuttle 

missions. It was selected for SLS for its power, efficiency, 

and reliability—as well as the knowledge and experience 

base. The liquid hydrogen and liquid oxygen-powered 

engines are compact and highly efficient and provide 

high performance.

The RS-25 is a type of engine known as a staged-combustion 

cycle engine that burns liquid hydrogen and liquid oxygen 

propellants at very high pressure. At full throttle, the four 

engines will give SLS about two million of its 8.8 million 

pounds of maximum thrust. The SLS engines start in 

a staggered fashion: engine 1, engine 3, engine 4, then 

engine 2, approximately six seconds before booster ignition. During ascent, the engines are gimballed, or pivoted, 

to direct thrust and steer the rocket.

Although SLS uses RS-25 engines that flew on the space 

shuttle, engineers made several physical and operational 

changes related to tailoring them to SLS operating 

requirements and environments. For SLS, the engines 

received new engine controllers with contemporary avionics, software changes to accommodate higher propellant 

inlet pressures and lower temperatures, and new exhaust 

nozzle insulation for the higher heating environment. The 

engines will operate in temperature extremes from -423 

degrees Fahrenheit (-253 degrees Celsius) to 6,000 degrees 

Fahrenheit (3,316 degrees Celsius) and at pressures exceeding 7,000 psi (48,263 kPa). For SLS missions, the modified 

RS-25s can deliver thrust ranging from 65% to 109% of 

their original operational profile, a 5% gain in maximum 

thrust from the end of the Space Shuttle Program.

T﻿he modified RS-25s can operate at 109% of their original 

operational thrust level for SLS missions, a 5% gain from 

the end of the Space Shuttle Program. As new RS-25s are 

built for future missions, they will produce 111% operational thrust levels and incorporate advanced manufacturing methods that will streamline cost and production.

RS-25 Engine Flight Histories for Artemis I

FLIGHT DATE ORBITER

ENGINE 1—2045

STS-089 01/22/98 Endeavour

STS-092 10/11/00 Discovery

STS-095 10/29/98 Discovery

STS-102 03/08/01 Discovery

STS-105 08/10/01 Discovery

STS-110 04/08/02 Atlantis 

STS-113 11/23/02 Endeavour

STS-118 08/08/07 Endeavour

STS-121 07/04/06 Discovery

STS-127 07/15/09 Endeavour

STS-131 04/05/10 Discovery

STS-135 07/08/11 Atlantis

The Artemis II RS-25 engines are designated as backups for the Artemis I engines. Engines 2047, 2059, 2062, and 2063 have completed modification 

and are ready for flight if needed.

FLIGHT DATE ORBITER

ENGINE 2—2056

STS-104 07/12/01 Atlantis

STS-109 03/01/02 Columbia 

STS-114 07/26/05 Discovery

STS-121 07/04/06 Discovery

ENGINE 3—2058

STS-116 12/09/06 Discovery

STS-119 03/15/09 Discovery

STS-120 10/23/07 Discovery

STS-124 05/31/08 Discovery

STS-129 11/16/09 Atlantis

STS-133 02/24/11 Discovery

FLIGHT DATE ORBITER

ENGINE 4—2060

STS-127 07/15/09 Endeavour 

STS-131 04/05/10 Discovery 

STS-135 07/08/11 Atlantis

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Solid Rocket Boosters

The SLS twin solid rocket boosters, manufactured by lead 

booster contractor Northrop Grumman, provide more than 

75% of the total SLS thrust at launch and for the first two 

minutes of flight. The SLS booster design is based on the 

space shuttle boosters, with an additional propellant segment 

to provide more power, as well as several other upgrades. 

Standing 177 feet tall, the SLS booster is the largest, most 

powerful solid propellant booster ever built for flight, with 

more than three million pounds of thrust generated by each 

booster. While the boosters are using metal casings and parts 

that were flown on space shuttle missions, they have many 

new upgrades and parts, including a new case insulation-liner 

configuration, new exhaust nozzle design, and new avionics 

systems to control flight. In addition, the SLS boosters 

undergo an improved, nondestructive evaluation process to 

confirm each motor’s readiness for launch.

Engineers are designing next-generation boosters that will 

power SLS flights after all available shuttle-era hardware 

is expended. Teams are testing small-scale solid rocket 

motors to evaluate new components, including propellant, 

insulation materials, and nozzle materials for future SLS 

Block 2 flights before proceeding into full-scale testing.

Interim Cryogenic Propulsion Stage

Measuring 45 feet (13.7 meters) tall and 16.7 feet 

(5.1 meters) in diameter, the ICPS is a single-engine liquid 

hydrogen and liquid oxygen-based system that provides 

propulsion in space after the solid rocket boosters and 

core stage are jettisoned. The ICPS is based on the Delta 

Cryogenic Second Stage, which uses the RL10 engine, 

both of which have completed extensive testing and served 

on numerous flights of the United Launch Alliance (ULA) 

Delta IV rocket, with the RL10 completing its 500th flight 

in 2020. Modifications to the Delta Cryogenic Second 

 Teams with NASA’s Exploration Ground Systems and contractor Jacobs 

integrate the ICPS with LVSA atop the rocket’s core stage in the agency’s 

VAB at Kennedy on July 5, 2021. Image credit: NASA

Technicians with Exploration Ground Systems move the LVSA for the 

SLS rocket into the VAB at Kennedy on July 30, 2020, for processing. Image 

credit: NASA

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Stage for SLS included lengthening the liquid hydrogen 

tank, adding hydrazine bottles for attitude control, and 

making minor avionics changes. The ICPS is powered by 

one RL10 engine manufactured by Aerojet Rocketdyne 

and generates 24,750 pounds of maximum thrust.

Launch Vehicle Stage Adapter

The SLS adapters connect parts of the rocket, change its 

diameter, and protect electronics during ascent. The coneshaped launch vehicle stage adapter, also known as the 

LVSA, partially encloses the ICPS and connects to the 

SLS core stage below and the Orion stage adapter above. 

In addition to providing structural support for launch and 

a separation system, the LVSA also protects avionics and 

electrical devices in the ICPS from vibration and acoustic 

conditions during launch and ascent. The LVSA is 27.5 

feet tall and measures 27.5 feet in diameter at the base 

and tapers to 16.5 feet in diameter at the top. Once the 

core stage propellant is expended and the rocket is in 

Earth orbit, a component at the top of the adapter that is 

designed to break apart, a pneumatically actuated frangible joint assembly, separates the core stage and the LVSA 

from the ICPS, Orion stage adapter, and Orion.

Orion Stage Adapter

The Orion stage adapter connects the ICPS to the Orion 

spacecraft. The adapter measures 18 feet in diameter and 

5 feet tall and is made of lightweight aluminum. The 

adapter contains a diaphragm that provides a barrier to 

prevent gases, such as hydrogen, generated during launch 

from entering Orion.

For Artemis I, the Orion stage adapter will also carry 

small satellites, called CubeSats, as secondary payloads 

for research or technology demonstrations. The CubeSats 

are no more than 30 pounds each, about the size of a large 

shoebox, and do not require any extra power from the 

rocket to function. The adapter contains a comprehensive 

secondary payload deployment system for the CubeSats, 

including mounting brackets for commercial-off-the-shelf 

dispensers, cable harnesses, a vibration isolation system, 

and an avionics unit.

Following separation from Orion and after the spacecraft 

is a safe distance away, the avionics unit in the secondary 

payload deployment system will begin sending signals to 

release the payloads at pre-scheduled times. Following 

secondary payload deployment, the Orion stage adapter 

remains attached to the ICPS as the ICPS continues on its 

disposal trajectory.

Avionics and Software

The SLS core stage, boosters, and ICPS have computers 

and software that monitor and control their functions. 

 In High Bay 4 of the VAB at Kennedy Space Center, pathfinders, or fullscale replicas of SLS solid rocket booster segments, are stacked during a 

training exercise on Jan. 8, 2020. Image credit: NASA

Small satellites, called CubeSats, are shown secured inside 

NASA’s Orion stage adapter at Kennedy Space Center on Aug. 5, 2021. 

Image credit: NASA

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Space Launch System > Elements

ARTEMIS REFERENCE GUIDE

Avionics are the electrical systems necessary for flight and 

are driven by software to tell the rocket where it should 

go and how it should steer the engines to keep on the 

right trajectory. The core stage contains avionics in the 

forward skirt, intertank, and engine section, as well as the 

engines themselves. The avionics in the boosters and ICPS 

are connected to the flight avionics in the core stage. The 

core stage flight computers use data from the distributed 

avionics systems and its own flight computers to control 

the rocket and carry out its mission, transmitting performance data to controllers on the ground and Orion crew 

on future missions.

Core stage avionics and flight software serve as the 

“brains” of the rocket. They execute the commands to 

prepare and launch SLS, route data and commands to 

the stage, distribute power, produce navigation and flight 

control data, produce range safety tracking data, execute 

flight termination commands, produce motion imagery, 

provide telemetry to ground systems, synchronize and 

process data, monitor stage conditions, and receive and 

execute flight safety commands.

Core stage avionics consist of four main subsystems:

• Flight control

• Telemetry

• Flight safety

• Electrical power

Three flight computers and four power, data, telemetry, 

and navigation systems are located in the forward skirt. 

Avionics throughout the elements of SLS monitor the rocket’s health and control the flight.

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Space Launch System > Testing

ARTEMIS REFERENCE GUIDE

Each of the three flight computers uses three microprocessors. Each flight computer runs the same software for 

redundancy. The intertank houses 26 avionics systems 

for power, power distribution, data receiving and handling, telemetry, and camera control. The engine section 

contains 10 avionics systems related to navigation and 

engine monitoring.

SLS flight software was developed at Marshall and provides the flight and pre-flight software functions necessary 

for pre-launch procedures on the pad, as well as launch 

and ascent up to ICPS separation.

Flight Control System

The flight control system, led by three redundant flight 

computers, monitors the rocket’s condition, senses vehicle 

motion, generates navigation and control data, actuates 

main propulsion system valves, monitors the main propulsion system and engine controls, and routes commands 

to engine thrust vector control systems and controllers.

Core Stage Telemetry System

The core stage telemetry system includes radio and ethernet communications with the ground, telemetry control, 

engineering and development flight instrumentation, and 

a motion imagery system.

Flight Safety System

The flight safety system provides range tracking data and 

controls the rocket’s flight termination system located 

in the core stage and boosters. For safety, all rockets are 

required to have a flight termination system that can 

remotely destroy the rocket to end the flight if it were to 

go off-course.

Avionics Power System

The avionics power system distributes ground power, 

stores ground power for flight, and provides data to 

ground control centers.

Testing

The SLS Program conducted extensive testing on the 

rocket, ranging from basic structural materials testing to 

element-level testing of the engines, boosters, core stage, 

and upper stage elements, as well as full integrated testing 

of the entire Artemis I SLS rocket.

RS-25 Engine Testing

The RS-25 has successfully flown on 135 space shuttle 

missions and has accumulated more than 3,000 starts 

and one million seconds of ground and flight hot fire 

experience. NASA conducted a series of development 

engine ground tests to adapt the former shuttle engine 

design to SLS performance requirements and operating 

environments. The 14 flown shuttle engines required no 

further testing. Two new engines assembled from shuttle-era spares were hot fire tested. New engine controllers 

for all 16 engines were hot fire tested as part of the development engine adaptation series. The agency continues 

development engine ground testing as part of an ongoing 

program to develop new RS-25 engines and components 

for future Artemis missions. 

The core stage for the first flight of NASA’s SLS rocket is shown in the 

B-2 Test Stand during a hot fire test at Stennis on Jan. 16, 2021, as part of 

the Green Run testing series. Image credit: NASA

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Space Launch System > Testing

ARTEMIS REFERENCE GUIDE

rocket stage before its first flight. After manufacture at 

Michoud, the stage was transported by barge to Stennis 

and installed in the B-2 test stand.

1. Modal Test: For the modal test, engineers applied 

forces to the stage mimicking the stresses the rocket 

will endure during launch and flight to validate 

computer models of structural vibration “modes” and 

establish a baseline for Green Run testing.

2. Avionics: The second test was a checkout of the avionics and flight computers, which control the rocket’s 

first eight minutes of flight.

3. Fail-Safes: The third test simulated potential issues 

to check out all the safety systems that shut down the 

stage in case of an issue.

4. Propulsion: The fourth test of the series flowed propellants through the core stage lines, ducts, and valves 

supplying the engines.

5. Thrust Vector Controls: During the fifth test, engineers operated the actuators in the thrust vector control system that steer the four engines and checked all 

the related hydraulic systems.

6. Countdown: The sixth test simulated the launch countdown, including step-by-step fueling procedures, and 

the test team exercised and validated the countdown 

timeline and sequence of events.

7. “Wet” Dress Rehearsal: During the seventh test, 

known as the wet dress rehearsal, engineers demonstrated loading, controlling, and draining more than 

700,000 gallons of cryogenic propellants into and out 

of the core stage and then returning the stage to a safe 

condition.

8. Hot Fire Test: The final Green Run test culminated 

with firing all four engines together in early 2021 for 

eight minutes—the same amount of time it will take 

to send Orion and the upper stage to space. After an 

initial test that was shut down after 61 seconds by 

conservative test parameters to ensure the safety of the 

flight stage, the test team modified the software and 

the stage and successfully completed a full-duration 

hot fire test.

Structural Testing

Structural testing of the core stage and the ICPS took 

place at Marshall from 2017 through 2020. These tests 

helped verify computer models showing that the structural 

Following a successful Green Run hot fire test at Stennis on March 18, 

2021, teams lift the first core stage of the agency’s SLS rocket from the 

B-2 Test Stand. Image credit: NASA

Booster Testing

The SLS solid rocket boosters completed five test firings 

and qualification motor testing in a horizontal position at 

Northrop Grumman’s facility in Promontory, Utah. The 

first qualification motor test in March 2015 tested booster 

operation under high-temperature launch conditions, 

and the second and final qualification test in June 2016 

chilled the motor to test it under cold-weather conditions. 

Qualification testing also validated major motor upgrades, 

such as new insulation, updated avionics, and a redesigned 

larger nozzle.

Core Stage Green Run Testing

The Artemis I core stage with its four RS-25 engines 

underwent a series of eight “Green Run” tests in 2020 and 

early 2021 to thoroughly check out the new, or “green,” 

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ARTEMIS REFERENCE GUIDE

design can survive flight. Special test stands subjected test 

articles for the core stage engine section, liquid hydrogen tank, intertank, and liquid oxygen tank to millions 

of pounds of flight-like pushing, pulling, bending, and 

twisting stresses. This testing also included deliberately 

pushing the propellant tanks beyond their design limits 

to understand their breaking points. The tanks failed in 

the relative locations as engineers predicted and at the 

approximate load levels expected, proving flight readiness 

and providing data for designers.

In a separate test program completed in 2017, the SLS 

team performed similar structural testing for the ICPS 

and payload sections, including the LVSA, the Orion 

stage adapter, and a frangible joint assembly.

Wind Tunnel Testing

The SLS team completed numerous tests that simulated 

launch and flight conditions. Engineers conducted extensive wind tunnel testing at NASA’s Ames Research Center 

in Moffett Field, California; Langley Research Center 

in Hampton, Virginia; and Marshall. Wind tunnel tests 

A model of SLS is tested in the Unitary Plan Wind Tunnel at Langley using high-pressure air blown through the solid rocket boosters to simulate the 

booster separation motors’ firing. Image credit: George Homich

The SLS liquid hydrogen tank is pushed to its limits on Dec. 5, 2020, to 

see how much force it would take to cause the tank’s structure to fail. This 

image shows the resultant buckling of the structure when the tank failed 

after exposure to more than 260% of expected flight loads over 5 hours. 

Image credit: NASA

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Space Launch System > Management Roles and Facilities

ARTEMIS REFERENCE GUIDE

used smaller-scale rocket models to refine designs and 

smooth airflow in flight and to determine the effects of 

wind before the rocket clears the launch tower, how SLS 

heats up as it pushes through the atmosphere, and how 

it vibrates and responds at or near the speed of sound. 

During hundreds of test runs at Langley and Ames, engineers worked on measuring the forces and loads that air 

induces on the rocket during every phase of its mission.

Management Roles and Facilities

Marshall Space Flight Center

Marshall is home to the SLS Program Office and manages 

all areas of the program, including planning, procurement, 

development, testing, evaluation, production, and operation of the integrated rocket. Marshall also developed and 

tested the flight software in-house.

Michoud Assembly Facility

The hardware welded at Michoud included confidence, 

qualification, and flight components of the SLS core 

stage. Confidence articles verified that weld procedures 

worked as planned and tooling-to-hardware interfaces 

were correct. It also gave the weld team experience in 

bringing all aspects of hardware, tooling, and software 

together. Qualification articles closely replicated flight 

hardware and processing procedures. Engineers later used 

the qualification articles in structural testing to ensure 

that the rocket design was sound.

Engineers and technicians used six state-of-the-art welding tools for the core stage, including the world’s largest 

spacecraft welding tool, the Vertical Assembly Center. 

At 170 feet tall, the Vertical Assembly Center is the last 

stop in welding the primary structure and is used to join 

domes, rings, and barrels to make a completed section of 

the core stage.

Katherine Johnson Independent Verification and 

Validation Facility

The Katherine Johnson Independent Verification and 

Validation (IV&V) facility assures the safety and success 

of software on NASA’s highest-profile missions. IV&V 

has supported the development of SLS software for more 

than a decade, providing significant value in improving 

the software products as well as the reliability, safety, 

and success of the Artemis mission. Collaboration with 

the development and test teams resulted in the resolution 

of more than 3,000 identified higher-severity issues that 

were found in phase with the software development life 

cycle—ultimately contributing to the SLS Program’s 

flight readiness for Artemis I.

Stennis Space Center

The SLS Program includes a Resident Management Office 

at Stennis Space Center, which conducts SLS engine and 

stage Green Run testing. Stennis provides propulsion testing and engineering services and is the nation’s premier 

rocket propulsion test facility and largest rocket engine 

test site.

Kennedy Space Center

The SLS Program includes a Resident Management Office 

at Kennedy, responsible for receiving and integrating SLS 

hardware, as well as overall integration with Orion and 

launch operations in coordination with the Exploration 

Ground Systems Program.

Ames Research Center

Engineers conducted wind tunnel tests on smaller-scale 

rocket models of SLS at Ames to enhance the design and 

stability of the rocket.

Langley Research Center

Engineers at Langley completed testing for the SLS rocket 

in a low-speed wind tunnel.

Industry Partners

Boeing is the lead contractor for the SLS core stage and 

ICPS, as well as the exploration upper stage for future 

missions beginning with Artemis IV. Boeing manufactures the core stage at Michoud and works with ULA in 

Decatur, Alabama, to modify the Delta Cryogenic Second 

Stage for use as the ICPS on Artemis I through III.

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Northrop Grumman is the lead contractor for the fivesegment solid rocket boosters, which are the largest ever 

built for spaceflight. Northrop Grumman manufactures 

the booster motors in Utah and then transports them by 

rail to Kennedy to be stacked with the aft and forward 

assemblies in the Rotation, Processing and Surge Facility.

Aerojet Rocketdyne is the lead contractor for adapting 

16 existing RS-25 engines that were upgraded from the 

Space Shuttle Program to SLS operating conditions and 

requirements, as well as restarting production of the RS-25 

engines for flight at a higher thrust level. Assembly and 

testing occur at the company’s facility located at Stennis. 

Aerojet Rocketdyne also provides the single RL10 engine, 

manufactured in its West Palm Beach, Florida, facility, 

that will power the ICPS.

Teledyne Brown Engineering is the lead contractor for 

the launch vehicle stage adapter, providing engineering, 

technical support, and hardware for the Artemis I adapter 

and structural test article. Teledyne Brown manufactures 

the adapter using the friction stir welding tools in the 

Advanced Weld Facility at Marshall.

At NASA’s Michoud Assembly Facility in New Orleans, Orion’s newly completed pressure vessel for the Artemis III mission is lifted out of the welding 

tool. Image credit: NASA

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Space Launch System > Quick Facts

ARTEMIS REFERENCE GUIDE

Quick Facts

SLS Rocket

Design Evolvable super heavy-lift

Height 322 ft (98.3 m)

Weight 5.74 million lb (2,603 metric tons [t]) fueled; 3.5 

million lb (1,588 t) unfueled

Main propulsion Four RS-25 liquid propellant engines and two 

five-segment solid rocket boosters

Maximum thrust 8.8 million lb (39,144 kN)

Maximum speed 22,600 mph (36,371 km per hour [kph]) at ICPS 

trans-lunar injection (TLI) main engine cutoff

Payload to 

low-Earth orbit

209,439 lb (95 t)

Payload to TLI > 59,525 lb (27 t)

Core Stage

Contractor Boeing

Height 212 ft (64.6 m) from forward skirt to engine 

exhaust exit plane

Diameter 27.6 ft (8.4 m)

Weight 2.4 million lb (1,088 t) fueled without engines and 

188,000 lb (85.3 t) unfueled without engines

Capacities 537,000 gal (2 million L), 317,000 lb (143.8 t) 

liquid hydrogen fuel; 196,000 gal (741,941 L), 1.86 

million lb (843.7 t) liquid oxygen oxidizer

Maximum thrust Approximately 2 million lb (8,896 kN)

Burn Time 8 minutes

Additional Facts

• There are: 

• 562 cables in the core stage; The largest number—231—are 

located in the engine section;

• 45 miles of cabling in the core stage, and more than 18 miles in 

the engine section alone;

• 775 independent sensors that have wire routing to them; and

• approximately 100,000 clamps and ties securing wires and 

cables throughout the core stage.

• The liquid hydrogen tank shrinks about 6 in (152 mm) in length and 

1 in (25.4 mm) in diameter when filled with cryogenic propellant.

• The liquid oxygen tank shrinks approximately 1.5 in (38.1 mm) in 

length and 0.5 in (12.7 mm) in diameter when filled with cryogenic 

propellant.

• To compensate for those changes, everything that attaches to 

them—ducts, vent lines, systems tunnel, brackets, etc.—must 

be connected by accordion-like bellows sections, slotted joints, 

telescoping sections, or ball joint hinges.

• Roughly 14,500 fasteners need to be drilled and filled in the 

intertank.

• Each flight computer is rated to operate over a temperature range 

of minus 11 degrees to 97.7 degrees Fahrenheit (minus 24 degrees 

to 36.5 degrees Celsius).

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Space Launch System > Quick Facts

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RS-25 Engines

Contractor Aerojet Rocketdyne

Height 14 ft (4.3 m)

Diameter 8 ft (2.4 m)

Weight (each) 7,750 lb (3.5 t)

Propellants Liquid hydrogen, liquid oxygen

Maximum thrust 418,000 lb (1,852 kN) at sea level; 512,300 lb 

(2,279 kN) in a vacuum at 109% power level

Burn time 8 minutes

Additional Facts 

• The RS-25 exhaust is clean, superheated water vapor.

• Each turbine blade powering the RS-25’s high-pressure fuel 

turbopump produces more horsepower than a Corvette ZR1’s 638 

horsepower, and its airfoil is the size of a quarter.

• Pressure within the RS-25 is equivalent to that found at an ocean 

depth of 3 mi—about the same distance as Titanic’s resting place 

below the surface of the Atlantic Ocean.

• Hot gases exit the RS-25’s nozzle at 9,600 mph (15,450 kph)—13 

times the speed of sound, or fast enough to go from Los Angeles to 

New York City in 15 minutes.

• Four RS-25 engines push the SLS rocket 73 times faster than an 

Indianapolis 500 race car travels.

• The RS-25 is so powerful that it could power 846,591 mi of 

residential streetlights—a street long enough to go to the Moon 

and back, then circle Earth 15 times.

• SLS’ four RS-25 engines consume propellant at the rate of 1,500 

gal (5,678 L) per second during their 8 minutes of operation—more 

than enough to drain an Olympic-size swimming pool in that time.

• The RS-25 generates about 20% more thrust at sea level than 

comparable kerosene engines using the same amount of fuel.

• While the RS-25 is about the same size and weight as the two 

turbojet engines on an F-15 fighter, it generates eight times more 

thrust, which it achieves in less than 5 seconds, operating between 

minus 400 degrees Fahrenheit (minus 240 degrees Celsius) and 

6,000 degrees Fahrenheit (3,316 degrees Celsius).

• In the RS-25, coolant travels through the main combustion chamber 

in 2 milliseconds, increasing its temperature by 400 degrees 

Fahrenheit (204 degrees Celsius).

Solid Rocket Boosters

Contractor Northrop Grumman

Height 177 ft (54 m)

Diameter 12 ft (3.7 m)

Weight (each) 1.6 million lb (726 t) loaded; 219,000 lb (99.3 t) 

empty

Solid rocket motor Five propellant segments

Propellants Polybutadiene acrylonitrile (PBAN)

Maximum thrust 3.6 million lb (16,014 kN) each (vacuum)

Burn time 2 minutes, 6 seconds

Interim Cryogenic Propulsion Stage 

(Upper Stage)

Contractor Boeing and United Launch Alliance

Designation Interim Cryogenic Propulsion Stage (modified 

Delta IV Cryogenic Second Stage)

Height 45 ft (13.7 m)

Diameter 16.7 ft (5.1 m)

Weight 72,197 lb (32.7 t) fueled

Engine Aerojet Rocketdyne RL10B-2

Propellants Liquid hydrogen, liquid oxygen

Maximum thrust 24,750 lb (110 kN)

Reaction Control 

System 

Hydrazine

Launch Vehicle Stage Adapter

Contractor Teledyne Brown Engineering

Height 27.5 ft (8.4 m)

Diameter 27.5 ft (8.4 m) bottom; 16.5 ft (5 m) top

Weight 10,000 lb (4.5 t)

Orion Stage Adapter

Manufacturer NASA’s Marshall Space Flight Center

Height 5 ft (1.5 m)

Diameter 18 ft (5.5 m)

Weight 1,800 lb (0.8 t)

Available payload 

volume

516 ft3 (14.6 m3

)

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Space Launch System > Super Heavy Lifting on the Ground: Transportation, Logistics, and Pathfinder

ARTEMIS REFERENCE GUIDE

Super Heavy Lifting on the Ground: 

Transportation, Logistics, and 

Pathfinders

The SLS Program provided several full-scale “pathfinders” 

to give transportation and ground handling crews the 

opportunity to rehearse and perfect logistics and handling procedures prior to receiving Artemis I hardware 

and pave the way for smooth shipping, handling, and 

lifting operations.

The core stage pathfinder is a full-scale mockup structurally similar to the core stage in shape, size, weight, 

center of gravity, and handling interfaces. Lacking the 

internal tanks and equipment of the flight hardware, the 

pathfinder was used to practice transport, handling, and 

lifting operations at NASA’s Michoud Assembly Facility 

in New Orleans, Louisiana; NASA’s Stennis Space Center 

near Bay St. Louis, Mississippi; and Kennedy.

Infographic with details of the Space Launch System core stage pathfinder. Image credit: NASA

24 Space Launch System > Super Heavy Lifting on the Ground: Transportation, Logistics, and Pathfinder
Space Launch System > Super Heavy Lifting on the Ground: Transportation, Logistics, and Pathfinder

ARTEMIS REFERENCE GUIDE

Moving flight hardware during manufacturing and testing 

within facilities and onto rail cars, barges, and aircraft 

requires care and specialized equipment. While the RS-25 

engines move by truck and the booster motor segments 

travel by rail, the core stage and launch vehicle stage adapter 

require their own transportation and handling equipment.

NASA’s Super Guppy aircraft has a cargo compartment 

that is 25 feet tall, 25 feet wide, and 111 feet long; it can 

carry more than 26 tons. The aircraft has a unique hinged 

nose that can open more than 200 degrees, allowing large 

pieces of cargo to be loaded and unloaded from the front. 

The Super Guppy has been responsible for the transportation of both SLS fight hardware and the Orion spacecraft.

NASA’s Pegasus barge is the largest vehicle used to transport SLS elements. Pegasus ferried the Artemis I core stage 

from Michoud, where it was manufactured, to Stennis 

for Green Run testing. After Green Run, Pegasus carried 

the core stage to Kennedy. Pegasus also transported the 

launch vehicle stage adapter from Marshall Space Flight 

Center in Huntsville, Alabama, to Kennedy.

Pegasus was designed and built in 1999 to transport 

space shuttle external tanks from Michoud to Kennedy. 

It replaced the Poseidon and Orion barges that were 

used to carry Saturn rocket stages and hardware for the 

Apollo Program. Pegasus was modified in 2014 to carry 

the longer SLS core stage. A 115-foot section was removed 

and replaced with a 165-foot section capable of carrying 

more weight and lengthening Pegasus from 260 feet to 

310 feet. Pegasus has no engines and is moved by tugboats 

and towing vessels.

For surface transportation, SLS relies on specialized 

ground support equipment. This is a set of modular 

equipment including smaller brackets, shackles, and pins 

that secure the giant rocket hardware to the slow-moving 

motorized transports that transfer rocket components 

between buildings, barge, and test stands.

Like the flight hardware that depends on it, the ground 

support equipment was designed and built to exact specifications; furthermore, every move is carefully choreographed by the operations teams.

NASA’s Pegasus Barge arrives at the Launch Complex 39 turn basin wharf at Kennedy Space Center in Florida on Sept. 27, 2019, to make its first delivery 

to Kennedy in support of the agency’s Artemis missions. Image credit: NASA

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Space Launch Systems > Quick Facts

ARTEMIS REFERENCE GUIDE

A full Moon is in view from Launch Complex 39B at NASA’s Kennedy Space Center in Florida on June 14, 2022. The Artemis I Space Launch System 

(SLS) and Orion spacecraft, atop the mobile launcher, were being prepared for a wet dress rehearsal to practice timelines and procedures for launch. 

Image credit: NASA

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ARTEMIS REFERENCE GUIDE

Orion 

Spacecraft

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ARTEMIS REFERENCE GUIDE

Introduction

NASA’s new spacecraft for human missions to deep space 

will usher in the next era of space exploration. Orion is 

composed of three main elements and supporting subsystems. The main elements are 1) the crew module, where 

astronauts live and work; 2) the service module, which 

provides power, propulsion, and critical supplies; and 

3) the launch abort system, which can pull the spacecraft 

and crew to safety in the event of an emergency during 

launch or ascent to orbit.

Drawing from more than 50 years of spaceflight research 

and development, the Orion spacecraft is designed to meet 

the evolving needs of our nation’s deep space exploration 

program for decades to come. A series of increasingly 

challenging missions awaits as Orion embarks on deep 

space expeditions to take humans farther than ever before, 

including to the vicinity of the Moon and beyond.

HELPFUL RESOURCES

For more information about the Orion program, visit

https://www.nasa.gov/orion

SOCIAL MEDIA

Twitter: https://www.twitter.com/NASA_Orion

Facebook: https://www.facebook.com/NASAOrion

Instagram: https://www.instagram.com/NASAArtemis

 Artist’s concept of the Orion spacecraft 

approaching the Moon.

...the Orion

spacecraft is 

designed to meet 

the evolving needs

of our nation’s deep 

space exploration 

program for decades

to come.

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ARTEMIS REFERENCE GUIDE

Orion Spacecraft > Introduction

Overview

The Orion spacecraft, built by lead contractor Lockheed 

Martin for NASA, is specifically designed to carry astronauts on deep space exploration missions farther than 

ever before and requires an array of features to keep the 

spacecraft and its crew safe. On deep space missions, 

both distance and duration dictate the capabilities and 

advanced technologies needed. No other spacecraft has 

the technology to endure the extremes of deep space, such 

as advanced environmental and life support, navigation, 

communications, radiation shielding, and the world’s 

largest heat shield to protect astronauts and return them 

safely home.

Artemis I will send Orion on an uncrewed flight test 

around the Moon and back to test the spacecraft’s systems 

and performance in a deep space environment before 

carrying astronauts beginning with Artemis II. Artemis I 

will test Orion’s navigation and communications systems 

beyond the range of GPS and above communication 

satellites in Earth orbit; test the radiation sensors and 

shielding outside the protection of Earth’s magnetic field; 

and test the world’s largest heat shield during a high-speed 

return from the Moon. Future missions with crew will 

also include advanced systems for life support designed for 

the demands of a deep space mission.

Future Missions and Configurations

Artemis II will be the first flight with astronauts aboard 

Orion. The spacecraft will be equipped with advanced 

environmental control and life-support systems designed 

to be highly reliable while taking up minimal mass and 

volume for deep space missions. Additional crew systems 

will include advanced display and control panels, a compact toilet, exercise equipment to help prevent muscle 

and bone atrophy, and spacesuits capable of keeping the 

astronauts alive for six days in the event of cabin depressurization to support a multi-day return from the Moon.

Deep space missions require highly reliable systems because 

astronauts at the Moon will not have the benefit of frequent 

resupply shipments to bring spare parts from Earth, like 

those to the International Space Station. Distance and 

duration for deep space missions have shaped the design of 

Orion’s compact systems, not only to maximize available 

space for crew comfort, but also to accommodate the volume needed to carry consumables, such as food and water 

for the entirety of a mission lasting days, weeks, or even 

months. Missions beyond Artemis II will also include a 

rendezvous and docking system for docking to a human 

landing system that will take astronauts to the surface of 

the Moon or to the lunar-orbiting Gateway outpost.

Artist’s concept of the separation of the Orion spacecraft from the Interim Cryogenic Propulsion System.

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ARTEMIS REFERENCE GUIDE

Orion Spacecraft > Elements

Elements

Crew Module

The crew module is the pressurized part of the Orion 

spacecraft, sometimes referred to as the capsule, where 

crew members on future missions will live and work on 

their journey to the Moon and back to Earth; it is the 

only portion of Orion that returns to Earth at the end 

of the mission. Although Artemis I is an uncrewed 

mission, the crew module can accommodate four crew 

members on future missions for up to 21 days without 

docking with another spacecraft, and it will provide a 

safe habitat through launch, in-orbit operations, landing, 

and recovery.

Pressure Vessel

The underlying structure of the crew module is called 

the pressure vessel. The pressure vessel consists of seven 

large aluminum alloy pieces that are joined together using 

friction stir welding to produce a strong, yet lightweight, 

airtight capsule. The seven major structural pieces include 

the barrel, the tunnel, the forward and aft bulkheads, 

and three cone panels. Orion’s original designs required 

33 welds to create the pressure vessel. Engineers refined 

the design to reduce the number of welds to seven on 

Artemis I, saving 700 pounds of mass on the spacecraft.

Illustration showing the major components of the Orion spacecraft.

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ARTEMIS REFERENCE GUIDE

Orion Spacecraft > Elements

Back Shell

Covering the pressure vessel, on the sides of the crew module, is the back shell, made up of 1,300 thermal protection 

system tiles. These tiles are made of a silica fiber material 

similar to the tiles used for more than 30 years on the 

space shuttle, and they incorporate a stronger coating 

called “toughened uni-piece fibrous insulation,” or TUFI 

coating, which was used toward the end of the Space 

Shuttle Program. The tiles protect the spacecraft from 

in-space micrometeoroid debris as well as the extreme 

temperature variances from the –350-degree-Fahrenheit 

coldness of space to the 5,000-degree heat when entering 

Earth’s atmosphere at lunar return velocities. Spacecraft 

returning from the Moon reenter Earth’s atmosphere 

faster and hotter than spacecraft from low-Earth orbit.

Forward Bay Cover

At the top of the crew module, the forward bay cover 

protects the top portion of the capsule, as well as the 

parachutes, during launch, orbital flight, and reentry; it is 

covered with the same thermal protection tiles as the back 

shell. After the spacecraft reenters Earth’s atmosphere, it 

is jettisoned at an altitude of approximately 23,000 feet 

to allow for deployment of the parachute system. The 

parachute system includes a series of 11 parachutes that 

are deployed in a sequence to slow down the module from 

about 325 mph to 20 mph or less and provide a safe speed 

for splashdown into the ocean.

Heat Shield

The bottom of the Orion capsule is covered by the world’s 

largest ablative heat shield, measuring 16.5 feet in diameter. The heat shield sheds intense heat away from the crew 

module as Orion returns to Earth, traveling about 25,000 

mph and enduring temperatures about half as hot as the 

surface of the Sun at nearly 5,000 degrees Fahrenheit 

(2,760 degrees Celsius). The outer surface of the heat 

shield is made of 186 billets, or blocks, of an ablative 

material called Avcoat, a reformulated version of the material used on the Apollo capsules. The Avcoat is bonded to a 

titanium skeleton and composite skin that gives the shield 

its shape and provides structural support for the crew 

module during descent and splashdown. During descent, 

the Avcoat ablates, or burns off in a controlled fashion, 

transporting heat away from Orion.

The Avcoat is first made into large blocks at NASA’s 

Michoud Assembly Facility in New Orleans, then shipped 

to NASA’s Kennedy Space Center in Florida and machined 

into 186 unique shapes before application onto the heat 

shield. Engineers look for voids in the bond lines and also 

measure the steps and gaps between the blocks. The gaps 

are filled with an adhesive material and then reassessed. 

After the thermal protection system has been applied and 

inspected, engineers and technicians put the heat shield 

through a thermal cycle test. This testing ensures that the 

thermal protection blocks are properly bonded and will 

perform as expected when they are exposed to the extreme 

temperatures during the mission. The heat shield is then 

given a coat of white epoxy paint. Aluminized tape is 

applied after the painted surface dries to dissipate electrical surface charges and maintain acceptable temperatures. 

1

6

7

2

Tunnel

Forward

Bulkhead

Three

Cone

Panels

Barrel

Aft

Bulkhead

7 Welds of Orion’s Pressure Vessel

 Illustration of the seven aluminum alloy pieces that were welded together 

to create the Orion pressure vessel.

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Once all testing has been completed, the heat shield is 

bolted to the crew module.

Propulsion System

The crew module has a propulsion system composed of 

12 small engines, called reaction control system thrusters, provided by Aerojet Rocketdyne, that provide full 

control of crew module translation and rotation. When 

the crew module separates from the service module for 

reentry into Earth’s atmosphere, the 12 thrusters control 

the spacecraft’s return by firing bursts of propellant in 

varying sequences. 

Interior

Inside the crew module, the floor structure where the crew 

seats will be attached and where the crew stowage lockers 

will be located is called the backbone assembly, which is 

a nine-piece bolted structure of crisscrossing beams. The 

backbone, made of aluminum, also provides additional 

structural support for the crew module.

The seats in the crew module are designed to accommodate nearly 99% of the human population—from a 4 ́10 ̋ 

woman to a 6 ́5 ̋ man. Seats also include adjustable seat 

pans, foot plates, and arm rests, as well as adjustable hand 

controller mounts to ensure that astronauts can reach 

all the controls while in their pressure suits. Most of the 

equipment the crew will need to live in space on future 

missions, such as food, medical kits, emergency equipment (including masks and fire extinguishers), sleeping 

bags, and the pressure suits worn for launch and return 

to Earth will be stored in lockers located under the seats.

On crewed missions, the crew module will be configured 

with four seats. For the uncrewed Artemis I mission, only 

the commander’s seat will be flown. Sitting in that seat 

(designated seat number 1) will be a male-bodied manikin 

equipped with a spacesuit and two sensors to test radiation 

impacts that could affect a human body. Sensors under the 

headrest and behind the seat will record acceleration and 

vibration data throughout the mission. The space under 

During NASA’s Artemis I mission, two identical “phantom” torsos named Helga and Zohar will be equipped with radiation detectors while flying aboard 

Orion to measure the effects of radiation in space and to test for protection with Zohar wearing a vest, while Helga will not. Image credit: NASA

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the commander’s seat will be used to store lockers for the 

“official flight kit,” which will carry various mementos 

during the trip around the Moon and back to Earth.

In what would be the pilot seat location (designated seat 

number 2) will be mass simulator plates that work with 

accelerometer sensors to test seat vibration. In the space 

where the two rear, or lower, seats will be located on future 

missions will be two manikin torsos, called phantoms, 

that simulate human tissue and organs. The phantoms 

are part of an investigation to measure radiation levels 

during the mission and evaluate a radiation protection 

vest worn by one of the phantoms. Two accelerometers 

also will be attached on the lower seat back simulator 

where the phantom without the vest will be located, 

which is closest to the hatch. The accelerometers will 

provide a comparison of vibration in the upper and lower 

seats. During splashdown, all accelerometers will measure 

impact accelerations on these seat locations. The team will 

compare those accelerations to the measurements taken 

during water impact testing at NASA’s Langley Research 

Center in Virginia.

Environmental control systems will maintain cabin temperature, pressure, and humidity inside the capsule. The 

crew module also contains systems for avionics and power, 

and the sealed capsule provides the protection needed to 

safeguard spacecraft systems, and crew on future missions, 

from cosmic and solar radiation in deep space.

On future missions with astronauts, a life-support 

system will maintain oxygen and carbon dioxide levels, 

keeping crew healthy and comfortable. A cockpit with 

glass displays and control panels will allow the crew full 

control of Orion. Water tanks and a dispenser will provide 

drinking water and a simple way to rehydrate and warm 

food. The crew module’s waste management system, or 

lavatory, is designed for multi-week missions and will 

privately accommodate personal hygiene needs for both 

men and women. Astronauts will use Orion’s built-in 

exercise device, which supports both aerobic and strength 

training. The environmental control system will remove 

excess heat, humidity, and odor generated during exercise.

European Service Module

Orion’s European Service Module is provided by ESA 

(European Space Agency) and built by lead contractor 

Airbus. It is the powerhouse that fuels and propels the 

Orion spacecraft in space. The service module is located 

below the crew module and is designed for long-duration 

missions to deep space destinations. It provides critical 

Engineers work to fit three spacecraft adapter jettison fairing panels 

onto Orion’s service module inside Kennedy’s Neil Armstrong Operations 

and Checkout Building on Oct. 13, 2020. Image credit: NASA

Interior of the Orion Medium Fidelity Mockup at Johnson Space Center 

in Houston. Image credit: NASA

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functions for Orion, including propulsion, thermal control, and electrical power generated by the solar arrays.

The consumable storage system of the service module 

will provide potable water, nitrogen, and oxygen to the 

crew module on crewed missions. Potable water will be 

provided by the water delivery system and stored in four 

tanks with metal bellows, covering usable water needs 

of the crew for the duration of the mission. Oxygen and 

nitrogen will be provided by the gas delivery system and 

stored in four tanks.

The cylindrical module is unpressurized and about 13 feet 

high, including the main engine and tanks for gas and 

propellant. During launch, the service module fits into 

a 17-foot-diameter housing, surrounded by three fairing 

panels that protect it from the harsh environments of 

launch, such as heat, wind, and acoustic vibrations. 

Once Orion is above the atmosphere, the fairing panels 

surrounding the service module will be jettisoned and 

its four solar arrays will unfurl. After the spacecraft 

separates from the upper stage of the SLS rocket, the service module will propel Orion on its mission and help it 

return to Earth, detaching before the crew module enters 

Earth’s atmosphere.

The farther into space a spacecraft ventures, the more capable its propulsion systems need to be to maintain its course 

with precision and ensure its return home. In addition to 

its function as the main propulsion system for Orion, the 

service module is responsible for orbital maneuvering and 

position control. It’s equipped with a total of 33 engines: 

one main engine, eight auxiliary engines, and 24 reaction 

control thrusters.

The main engine is an orbital maneuvering system engine 

previously flown on space shuttle missions, provided 

by NASA and made by Aerojet Rocketdyne. The auxiliary engines are R4D-11 engines, also made by Aerojet 

Rocketdyne and provided by NASA. The reaction control 

thrusters are provided by ESA and are the same model as 

those used on the Automated Transfer Vehicles built by 

An artist’s impression of the Orion spacecraft with ESA’s service module. The module sits directly below Orion’s crew capsule and provides propulsion, 

power, thermal control, and water and air for four astronauts. The solar array spans 19 m and provides enough power for two households. Image credit: NASA

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ESA that carried cargo and resupply goods from Earth to 

the International Space Station between 2008 and 2015.

The main engine will provide major in-space maneuvering 

capabilities throughout the mission, including inserting 

Orion into a distant retrograde orbit around the Moon 

and also firing powerfully enough to depart the Moon’s 

orbit to return to Earth. The eight auxiliary engines are 

also used for translational maneuvers, essentially backing 

up the main engine. The 24 reaction control thrusters are 

used to steer and control Orion in orbit, but usually only 

12 are used and the other 12 are mostly backup. The propulsion system can also be used, during some late phases 

of the launch, for potential abort scenarios.

Orbital Maneuvering System Engine 

Flight History for Artemis I

FLIGHT DATE ORBITER

STS-41G 10/05/84 Challenger

STS-51J 10/03/85 Atlantis

STS-61B 11/26/85 Atlantis

STS-27 12/02/88 Atlantis

STS-30 05/04/89 Atlantis

STS-33 11/22/89 Discovery

STS-31 04/24/90 Discovery

STS-41 10/06/90 Discovery

STS-37 04/05/91 Atlantis

STS-43 08/02/91 Atlantis

STS-44 11/24/91 Atlantis

STS-45 03/24/92 Atlantis

STS-46 07/31/92 Atlantis

STS-101 05/19/00 Atlantis

STS-106 09/08/00 Atlantis

STS-98 02/07/01 Atlantis

STS-104 07/12/01 Atlantis

STS-110 04/08/02 Atlantis

STS-112 10/07/02 Atlantis

The service module’s structure is covered with Kevlar to 

absorb shocks from micrometeorites and debris impacts. 

During launch, the service module is held in place between 

the Orion crew module adapter—which connects the 

service module to the spacecraft’s crew module—and 

the spacecraft adapter, which attaches to the Orion 

stage adapter, Orion/service module’s connection to the 

SLS rocket. The crew module adapter houses electronic 

equipment for communications, power, and control, and 

it includes an umbilical connector that bridges the electrical, data, and fluid systems between the modules.

Computers control all aspects of the service module. The 

service module’s avionics manage the powered equipment 

of the module and the data-exchange services, which are 

based on instructions received from Orion’s flight computers in the crew module. Nearly seven miles of cables 

send commands and receive information from sensors.

The service module’s electrical power system provides 

power for the Orion spacecraft, manages the power 

generated by the four solar-array wings of the service 

module, and charges the main batteries on the crew 

module. Each solar array wing consists of three panel 

sections, and each panel is approximately 6.5 by 6.5 feet 

(2 by 2 meters). The total length of each wing is nearly 

23 feet (7 meters). There are a total of 15,000 gallium 

arsenide cells on the four arrays used to convert light 

into electricity, and the arrays can turn on two axes to 

remain aligned with the Sun for maximum power. A 

power control and distribution unit provides the power 

interface between the service module and the crew module adapter, distributes electrical power to service module’s electrical equipment, and protects the power lines.

The service module’s thermal control system includes 

radiators and heat exchangers to keep the equipment 

and future astronauts at a comfortable temperature. 

The thermal control system includes an active portion, 

which transfers the heat of the entire spacecraft to the 

service module’s radiators, and a passive portion, which 

protects the service module from internal and external 

thermal environments.

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Launch Abort System

Orion’s launch abort system, also known as the LAS, is 

designed to carry the crew to safety in the event of an 

emergency during launch or ascent atop NASA’s SLS 

rocket. It can activate within milliseconds to pull the 

spacecraft away from the rocket and position the module 

for a safe landing.

The LAS is divided into two parts: the fairing assembly 

and the launch abort tower. The fairing assembly is a shell 

composed of a lightweight composite material that protects the capsule from the heat, wind, and acoustics of the 

launch, ascent, and abort environments. The launch abort 

tower includes the system’s three motors.

The three solid rocket motors work together to propel 

Orion’s crew module to safety in an emergency: the abort 

motor pulls the crew module away from the rocket; the 

attitude control motor steers and orients the capsule; then 

the jettison motor ignites to separate the LAS from the 

crew module prior to parachute deployment.

The 17-foot-long, 3-foot-diameter abort motor, built by 

Northrop Grumman, has a manifold with four exhaust 

nozzles and provides thrust to quickly pull the crew 

module to safety if problems develop during launch. 

The high-impulse motor is designed to burn most of the 

propellant within the first three seconds and burns three 

times faster than a typical motor of this size to immediately deliver the thrust needed to pull the crew module 

to safety. If needed during a launch emergency, the crew 

module would accelerate from zero to 400–500 mph in 

just two seconds.

The attitude control motor, also built by Northrop 

Grumman, consists of a solid propellant gas generator 

and eight equally spaced valves capable of providing 7,000 

pounds of thrust in any direction. The unique valve control system enables each valve to open and close, directing 

the flow of gas. The motor operates to keep the crew module on a controlled flight path after it is pulled away from 

the rocket by the abort motor, and then it reorients the 

module for parachute deployment and landing.

The jettison motor was built by Aerojet Rocketdyne 

and is the only LAS motor that fires on every mission. 

During a normal launch, once SLS successfully clears 

most of the atmosphere and the LAS is no longer needed, 

the jettison motor fires to separate the LAS from the 

spacecraft. From this point, abort scenarios are handled 

by the engines in the service module. In a pad abort 

or launch abort scenario with crew, the jettison motor 

ignites to separate the LAS from Orion after the attitude 

control motor has reoriented the spacecraft and prior to 

parachute deployment and landing.

There will not be astronauts inside the spacecraft for 

the Artemis I mission, so the abort and attitude control 

motors will not be active. The jettison motor will still fire 

once Orion has reached orbit to enable the spacecraft to 

continue on the remainder of its journey. The full abort 

Inside the Launch Abort System Facility (LASF) at NASA’s Kennedy 

Space Center, the fully assembled Orion spacecraft for the agency’s 

Artemis I mission is prepared for transport. Image credit: NASA

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system has been thoroughly tested and certified for flights 

with astronauts beginning with Artemis II.

The tower-like abort structure is specifically built for deep 

space missions and to ride on a high-powered rocket. It is 

designed with its motors above the Orion crew module that 

pull the capsule away from the rocket, rather than push it 

away with motors at the base, as some other escape systems 

designed for other destinations are built to do. This design 

is ideal for deep space missions because it minimizes the 

mass that aborts in an emergency by leaving the service 

module behind and avoids carrying thousands of pounds 

of unwanted mass to deep space by fully jettisoning the 

entire LAS once it is no longer needed.

The Orion LAS also offers the highest thrust and acceleration escape system ever tested, generating 400,000 

pounds of thrust. In the event of an abort during ascent 

to orbit, the LAS can outrun the SLS rocket, which generates 8.8 million pounds of thrust. The puller-style system 

with the tower above the spacecraft is the first of its kind 

capable of controlling the spacecraft’s orientation after 

separating from the rocket.

Avionics and Software

The Orion primary flight computers have over 750,000 

lines of code that operate all the spacecraft systems, 

including power, communications, guidance, navigation, 

control, thermal management, instrumentation, and 

propulsion. For Artemis I, the software is fully automated 

and is able to execute the mission and handle numerous 

potential faults, including upsets due to radiation, without ground support. In addition, the software has a robust 

command and telemetry system that provides NASA’s 

Mission Control Center, or MCC, with the insight and 

ability to handle unforeseen circumstances and adjust 

software operation.

In the event of a complete failure of all flight computers 

during reentry, Orion has a backup flight computer with 

independently developed software that will take over 

control and safely land the spacecraft. This capability will 

Engineers at NASA’s Johnson Space Center in Houston are evaluating how crews inside a mockup of the Orion spacecraft interact with the rotational 

hand controller and cursor control device while inside their Modified Advanced Crew Escape spacesuits. Image credit: NASA

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be expanded to cover all phases of the flight for future 

missions. Software in computers other than the primary 

flight computers handles various other tasks, such as video 

processing and optical navigation. All of the software has 

been extensively tested in multiple laboratories and in 

nominal and off-nominal conditions to ensure that all the 

various subsystems are working together to execute the 

planned mission.

The Orion spacecraft also houses a number of state-ofthe-art avionics units to handle data generated by onboard 

systems, control the various functions of the spacecraft, 

carry out commands sent from the MCC (or by the crew 

on future missions), and return systems telemetry for 

insight into systems status.

The avionics and other electronics used in Orion are almost 

entirely driven by software and commercial processor 

technologies that have been ruggedized to endure extreme 

radiation and temperature fluctuations. Orion’s updated 

avionics also can handle the severe acoustic and vibration 

environments associated with launch, orbit, a fiery entry 

into Earth’s atmosphere, and a saltwater landing.

Orion’s avionics system consists of the following subsystems:

• Command and data handling

• Guidance, navigation, control, and propulsion

• Communications and tracking

• Power

• Instrumentation

• Displays and controls

Command and Data Handling

The brains of the Orion spacecraft consist of two vehicle 

management computers that deliver more computing 

power to the Orion spacecraft than any previous spacecraft designed for humans.

The Integrated Test Laboratory (ITL) has a full set of avionics, harnessing, sensors, and flight software identical to that on Orion. Using this real flight-like 

hardware and software, the lab is used to simulate and test every aspect of the EM-1 mission from launch to splashdown. Image credit: NASA

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Each of the vehicle management computers is made up 

of two flight computer modules (FCMs), which are in 

charge of flight control and other software; a communication control module that allows commands and data to 

flow between Orion and the MCC; and a display control 

module for astronaut displays that will be installed on 

future crewed Artemis missions. The FCMs provide a 

high-integrity platform to house software applications and 

have sufficient processing power to perform command 

and control of Orion. Each of the four FCMs is internally 

redundant and continually checks all operations to be sure 

they match. If the FCMs ever detect a difference between 

them due to a hardware failure or a radiation upset, the 

different FCM “fails silent” by stopping all outputs so that 

a potentially corrupted FCM doesn’t issue critical commands to the spacecraft. The FCM then resets itself, listens 

to the other FCMs to relearn where the spacecraft is and 

what is happening, and then rejoins the other FCMs in 

controlling the spacecraft—all within 22 seconds. Having 

four FCMs on the spacecraft allows the flight software to 

continue firing thrusters and flying as Orion transitions 

through the challenging radiation environment of the 

Van Allen belts, as the probability of all four FCMs being 

upset in the same 22 seconds is extremely low.

The four redundant FCMs greatly improve system reliability, yet Orion includes another measure of backup 

capability with the addition of a completely different 

computer, capable of running different code should it 

ever be needed. This capability is called the backup flight 

software. In the unlikely event that something goes wrong 

with the primary flight computers on Orion, a dissimilar processing platform with dissimilar flight software 

is hosted on a system called the vision processing unit. 

This dissimilar computer and software provide a backup 

function to the redundant FCMs during critical phases of 

flight, with a focus on crew survival and return functions 

in the highly unlikely scenario in which anything renders 

all the FCMs ineffective. The vision processing unit also 

provides a place to store data during times when Orion 

can’t communicate with the ground.

Eight power and data units (PDU) connect the flight 

computers and the software to the rest of Orion. These 

PDUs, each of which has two cards with two redundant channels on each card, control the power to every 

component on the spacecraft, and they control effectors 

such as valves, thrusters, and heaters. All sensor data, 

such as temperature and pressure, is routed through the 

PDUs as well. The PDUs also communicate with SLS as it 

launches Orion and puts it on its trajectory to the Moon.

Orion’s onboard data network is a triple-redundant network that allows the FCMs to communicate with all of the 

other avionic components on Orion. It uses a networking 

technology called Time-Triggered Gigabit Ethernet that is 

capable of moving data at a rate 1,000 times faster than 

systems used on the space shuttle and space station. This 

networking technology allows NASA engineers to categorize different types of data and prioritize how it should 

travel through the onboard network. Time-critical data 

relating to vital systems like navigation and life support, 

called time-triggered data, has guaranteed bandwidth and 

message timing to ensure it is always delivered exactly 

on time. Data that is critical for delivery but not timing, 

such as file transfers, is called rate-constrained data and 

is sent immediately whenever time-triggered data is not 

present. Data used for non-critical tasks such as crew videoconferencing is delivered over the remaining bandwidth. 

The technology means that critical data and non-essential 

data can travel safely over a single network on board a 

spacecraft for the first time. It is built upon a reliable commercial data bus that has been hardened to be resilient to 

space radiation and proven on Orion’s Exploration Flight 

Test-1. The data system interfaces with all components, 

Teams conduct power-up and docking operations for the Sensor Test for 

Orion Relative Navigation Risk Mitigation (STORRM) in a payload support 

room at Johnson Space Center’s Mission Control Center in Houston.

Image credit: NASA

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including the service module, through radiation-hardened 

network switches.

Guidance, Navigation, Control, and Propulsion

The Guidance, Navigation, Control, and Propulsion 

(GNC&P) system is responsible for always knowing where 

the spacecraft is and where it is going, and it controls the 

propulsion system to keep Orion pointed in the proper 

direction and on the correct trajectory.

At the center of this system is the GNC&P flight software 

that runs on the vehicle management computers. This 

software receives inputs from navigation sensors and pilot 

controls and commands the appropriate effectors on the 

crew module, service module, and LAS to accomplish 

mission objectives. The Orion GNC&P software operates 

across a variety of mission phases, including pre-launch, 

ascent, Earth orbit, transit to and from the Moon, and 

various abort scenarios, as well as loiter, rendezvous, 

docking, and entry on future missions. The software 

must operate in both manual and automated modes and 

must handle commands from the ground and the crew 

on future missions. The software must also run complex 

guidance and navigation algorithms while controlling 

highly dynamic configurations during reentry, ascent 

aborts, and orbital maneuvers.

The onboard navigation system for Orion is composed of a 

number of redundant sensors for measuring Orion’s position, which refers to where Orion is in space, and attitude, 

which refers to the direction the spacecraft is pointing. 

Like most systems on the spacecraft, there are usually at 

least two of each sensor to increase reliability of the overall 

system. Several different types of sensors are needed, as 

the spacecraft operates in the atmosphere during ascent 

and reentry, in low-Earth orbit, and near the Moon. These 

include the following:

• Orion Inertial Measurement Units: Each unit contains 

three devices, called gyros, that measure spacecraft 

body rotation rates and three accelerometers to measure spacecraft body accelerations. This inertial data 

is used by the vehicle management computers for 

onboard navigation to compute spacecraft position, 

velocity, and attitude.

• GPS Receivers: The GPS receivers on Orion are similar 

to ground-based receivers, except that these are capable 

of operating at the very high velocities of spaceflight. 

The GPS sensor system provides position and velocity 

updates during low-Earth orbit operations, ascent, and 

reentry. GPS-based altitude values are the primary 

triggers for entry events. Outside the range of GPS 

in deep space, Orion will rely on NASA’s Deep Space 

Network to determine the spacecraft’s location using 

sensitive measurements of communication signals 

that pass between Orion and large tracking dishes on 

the ground.

• Barometric Altimeter Assembly: By sensing the 

atmospheric air pressure outside the spacecraft during 

ascent and reentry, these assemblies can measure 

Orion’s altitude. They provide a backup altitude value 

for parachute and other deployments during entry.

• Star Trackers: The star tracker operates like a camera 

but is much more sensitive and takes pictures only of 

stars. By comparing the pictures to a known star catalog, the sensor determines spacecraft attitude during 

orbital operations.

• Optical Navigation Camera: The optical navigation 

camera takes images of the Moon and Earth. By 

looking at the size and position of these objects in the 

picture, the camera can determine Orion’s range and 

bearing relative to that object. The optical navigation 

camera is part of the Orion emergency return system 

to autonomously operate the spacecraft in the event of 

lost communication with Earth.

• Sun Sensors: The Sun sensors are located on the service module and are used to determine the direction of 

the Sun during emergency safe mode. Knowing where 

the Sun is ensures that Orion can point its solar arrays 

in the right direction to keep power flowing to the 

spacecraft. 

Communications and Tracking

Orion uses a high-speed communications system, employing four phased array antennas on the crew module and 

two phased array antennas on the service module. Phased 

array antennas allow signals to be controlled and directed 

without requiring any physical movement of the antenna. 

These will be used for video, data, and voice communications with the spacecraft, along with command uplink and 

telemetry downlink to ground stations, NASA’s Tracking 

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and Data Relay Satellite systems, and NASA’s Deep Space 

Network after leaving Earth’s orbit.

On future missions with crew, an emergency radio system will allow voice communications anytime during a 

mission if the main communications system fails, and 

search and rescue radios and satellite phones will be available after landing for communication with the recovery 

team. An audio system on board will enable astronauts to 

speak with each other and with the MCC while they are 

wearing spacesuits.

Power

The Orion power system is capable of generating and 

supplying all of the power that is required for its in-orbit 

operations. The four solar arrays, which are located on 

the service module, generate about 11 kilowatts of power. 

Power is transferred between the solar arrays and batteries and to the end systems via the power and data units. 

Orion’s four main batteries are located on the crew module 

and use small-cell packaging technology to ensure crew 

safety while providing 120 volts of power to the many 

systems on Orion. The batteries are fully charged before 

launch to operate the spacecraft until the solar arrays 

can be deployed once in orbit. The batteries also operate 

the spacecraft when the solar arrays cannot be pointed 

at the Sun or when Orion is in the shadow of Earth or 

the Moon. The solar arrays are jettisoned with the service 

module right before entering Earth’s atmosphere, so the 

batteries also provide all the power needed to keep the 

astronauts safe for return to Earth and up to 24 hours 

after splashdown. 

Instrumentation

Accomplishing flight test objectives requires a dedicated 

instrumentation system that will measure the dynamic 

response of all Orion subsystem performance during 

critical phases of the Artemis missions.

The developmental flight instrumentation (DFI) data 

system measures unique subsystem performance, such as 

spacecraft temperature and vibration, during all phases of 

the mission from launch, to flight in space, to return to 

Earth. The system is required to measure the response of 

newly designed components and structures to verify and 

validate engineering models that will be used to predict 

their future performance.

The architecture of the DFI system is robust and relies on 

proven hardware and software to deliver high reliability. 

The central components are data acquisition units that 

have two interfaces: one for the sensor interface and one 

for the control interface. The sensor interface communicates with the temperature, strain, accelerometers, and 

Goddard’s Networks Integration Center, pictured here, coordinated the communications support for both the Orion vehicle and the Delta IV rocket, 

ensuring complete communications coverage through NASA’s Space Network and Tracking and Data Relay Satellites. Image credit: NASA

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acoustic sensors. The control interface communicates with 

the power, control, recording, telemetry, and time-sync 

hardware. The sensors can be changed between flights 

to allow engineers to make adjustments based on what is 

learned about a previous flight.

Displays and Controls

On future missions, displays and control equipment 

inside the capsule will be the crew interface to the Orion 

systems. Without astronauts aboard Artemis I to test the 

displays and controls during the mission, Orion will carry 

mass simulators in place of the display and control panels 

as well as a technology demonstration payload for a digital crew interface that can respond to voice commands. 

Beginning with Artemis II, the displays and controls 

will consist of three display units, seven switch interface 

panels, two rotational hand controllers, two translational 

hand controllers, and two cursor control devices. Orion’s 

“glass cockpit” provides fully redundant crew controls 

and displays, with over 60 graphical user interface formats and interactive electronic procedures—a first in 

spacecraft history.

Parachutes

Also contained within the crew module are systems to 

support Orion’s safe return to Earth. Orion’s parachute 

system is designed to ensure a safe landing for astronauts 

returning from deep space missions to Earth in the crew 

module at speeds exceeding 25,000 mph, as well as during 

abort scenarios. While Earth’s atmosphere will initially 

slow the spacecraft down to 325 mph, the parachutes will 

slow Orion to a safe speed of 20 mph or less for landing in 

the Pacific Ocean.

The parachute system includes 11 parachutes made of 

36,000 square feet of parachute canopy material and 

attached to the top of the spacecraft with more than 

13 miles of Kevlar lines. Parachute deployment begins 

at about five miles in altitude with three forward bay 

cover parachutes used in conjunction with pyrotechnic 

linear thrusters to ensure separation of the forward bay 

cover, which protects Orion and its parachutes during 

the heat of reentry. The forward bay cover parachutes 

are packed using a hydraulic press, with forces as high as 

3,000 pounds.

Two drogue parachutes are deployed to slow and stabilize 

the crew module during descent and establish proper 

conditions for main parachute deployment to follow. The 

drogues are deployed by cannon-like mortars from the 

crew module forward bay at 100 feet per second (68 mph). 

The drogues are packed using a hydraulic press, with 

forces as high as 10,000 pounds.

Three pilot parachutes will lift and deploy the main 

parachutes from the crew module forward bay. They are 

mortar-deployed from the crew module forward bay at 

112 feet per second (76 mph). The pilots are packed using 

a hydraulic press for convenience but are much lower 

density and can be “hand packed” if required.

The three main parachutes will then slow the crew module 

to a speed that ensures astronaut safety during landing. 

Each of Orion’s main parachutes weighs 270 pounds 

Orion descends to Earth under three massive red-and-white main parachutes after its first flight test on Dec. 5, 2014. Image credit: NASA 

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and is packed to the density of oak wood to fit in the top 

part of the spacecraft, but once fully inflated, the three 

mains would cover almost an entire football field. The 

mains are packed using a hydraulic press, with forces as 

high as 50,000 pounds. They are autoclaved with a vacuum applied to the parachute at 190 degrees Fahrenheit 

(88 degrees Celsius) for 48 hours to help “set” the packing 

and remove atmospheric moisture.

Embedded in several parachutes are pyrotechnic riser cutters, which use fuses set to ignite at specific times and push 

blades through bulletproof materials to sever the lines at 

precise moments and allow the parachutes to unfurl to 

complete the deployment sequence. Within 10 minutes 

of descent through Earth’s atmosphere, everything must 

deploy and assemble itself in a precise sequence to slow 

Orion and its crew for a safe splashdown in the ocean. The 

parachute system also must be able to keep the crew safe 

in several failure scenarios, such as mortar failures that 

could prevent a single parachute from deploying, launch 

aborts, or other conditions that produce loads close to or 

exceeding the maximum material capability.

Crew Module Uprighting System

When Orion splashes down in the Pacific Ocean off the 

coast of San Diego, it will stabilize in one of two positions: 

the top of the capsule pointed up or top pointed down. 

The crew module uprighting system, known as CMUS, 

deploys a series of five bright-orange helium-filled bags on 

the top of the capsule to flip Orion right side up in the 

event it stabilizes upside down.

The five bags that make up the CMUS are packed in hard 

containers and installed atop the capsule inside the structural gussets between the parachutes and other equipment. 

The bags are inflated with helium gas that is stored in 

pressure vessels located close by the bags. Each bag has an 

independent inflation system. The CMUS system initiates 

after landing and opens a valve for helium to flow into the 

uprighting bags. As the gas fills the bags, they deploy from 

their containers and inflate to their full volume.

The CMUS will deploy regardless of the landing position 

of the capsule. It takes less than four minutes for the 

CMUS to upright the capsule, and the system will keep 

Orion upright and stable after splashdown in the ocean 

and for at least 24 hours, if necessary. The capsule must 

be upright for crew module communication systems to 

operate correctly and to help protect the health of the 

crew members inside on future missions from health 

impacts due to extended time hanging upside down in 

seat harnesses.

Testing

The Orion Program conducted rigorous testing of the 

spacecraft, from element-level testing with test articles for 

the crew module, service module, LAS, parachute system, 

and other supporting systems—including both flight tests 

The Orion Crew Module Uprighting System (CMUS) and Neutral 

Buoyancy Laboratory team completed two successful sea tests off 

the coast of Galveston, Texas. CMUS is designed to inflate five bags 

after the Orion spacecraft and its crew splash down after returning from deep space missions, enabling the capsule to right itself. 

Image credit: NASA

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and ground tests—to integrated testing of the full spacecraft that will fly on Artemis I.

Exploration Flight Test-1

Orion’s first uncrewed test flight, known as Exploration 

Flight Test-1, or EFT-1, demonstrated and validated the 

Orion crew module’s systems that are critical to crew 

safety, such as heat shield performance, separation events, 

avionics and software performance, attitude control and 

guidance, parachute deployment, and recovery operations.

The EFT-1 test flight launched a high-fidelity crew module and a mock service module on a ULA Delta IV Heavy 

rocket from Space Launch Complex 37 at Cape Canaveral 

Air Force Station in Florida. During the nearly four-anda-half-hour test flight, Orion orbited Earth twice, reaching 

an altitude of approximately 3,600 miles—about 15 times 

farther into space than the International Space Station—

before returning to Earth. At the end of the flight test, 

Orion landed in the Pacific Ocean and was recovered by 

NASA and the U.S. Navy.

Sending Orion to such a high altitude allowed the 

spacecraft to return to Earth at speeds near 20,000 mph. 

Returning at this speed, as fast as any spacecraft built for 

humans had endured since the Apollo program, exposed 

the heat shield to temperatures close to 4,000 degrees 

Fahrenheit, 80% of what the crew module would endure 

returning from the vicinity of the Moon. EFT-1 collected 

data to help NASA lower risks to the astronauts who 

will fly on Orion beginning with the Artemis II mission. 

This first flight also gave NASA the chance to continue 

refining its production and coordination processes, and 

Orion’s teams gained important experience and training 

in preparation for launching Orion on its first integrated 

flight with the SLS rocket.

Lockheed Martin technicians test the fitting of the Orion spacecraft’s heat shield back shell panels inside the Neil Armstrong Operations and Checkout 

Building high bay at NASA’s Kennedy Space Center in Florida. The back shell panels serve as the outer layer of the spacecraft and will protect it against the 

extreme temperatures of re-entry from deep space. Image credit: NASA

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Heat Shield Testing

Following Exploration Flight Test-1, the Orion heat 

shield was redesigned from a single-piece system to 

individual blocks of material. Before the time-saving 

block system was used, a fiberglass-phenolic honeycomb 

structure was bonded to the structure’s skin. Then each 

of the 320,000 tiny honeycomb cells were individually 

filled with Avcoat by hand, inspected by X-ray, cured in 

a large oven, and robotically machined to meet precise 

thickness requirements.

The new design introduced several considerations that 

prompted further testing for risk reduction. Engineers 

performed more than 30 tests across the United States 

on the new design to investigate the effects of the block 

structure that could disrupt the smooth airflow and 

cause localized heating spots. Understanding both effects 

confirmed that the heat shield will thermally protect the 

astronauts during entry into Earth’s atmosphere.

Teams tested the Avcoat material at NASA’s Ames 

Research Center’s Arc Jet Complex and at NASA’s 

Johnson Space Center’s Atmospheric Reentry Materials 

and Structures Evaluation Facility. Teams also performed thermal testing at Johnson’s Radiant Heat Test 

Facility. During these tests, the Avcoat surface reached 

temperatures of over 3,000 degrees Fahrenheit (1,649 

degrees Celsius). Heat shield testing also took place at 

NASA’s Langley Research Center with a 6-inch Orion 

heat shield model in the 20-inch Mach 6 wind tunnel. 

The model was machined to represent small-scale features, including the patterns expected as the heat shield 

ablates during return to Earth.

European Service Module 

Propulsion Testing

Engineers used a replica of the service module’s propulsion subsystem, called the propulsion qualification 

module (PQM), for testing at NASA’s White Sands Test 

Facility. The data from these tests helped to certify the 

service module propulsion system for the Artemis I and 

II missions and beyond. The PQM was designed to verify 

the performance of the service module engines, propellant 

feed systems, and various other propulsion operations 

during expected and unexpected conditions. Testing of 

the PQM ensured that all engines and thrusters fired 

safely and accurately to prove that they would be reliable 

in getting the spacecraft where it needs to go during deep 

space exploration missions.

The PQM was equipped with a total of 21 engines: one 

U.S. Space Shuttle Orbital Maneuvering System (OMS) 

engine, eight auxiliary thrusters, and 12 smaller reaction 

control system thrusters produced by Airbus in Germany. 

The service module that will fly on Artemis missions has 

33 engines in total, with double the amount of reaction 

control system thrusters included in the PQM. The full 

module was a roughly 15-foot cube made of stainless steel 

that provided the full components for testing the thrusters, fuel lines, and firing of Orion’s engines.

Teams from NASA and ESA completed 48 hot fire tests 

and three discrete pressurization tests conducted in two 

phases at White Sands. The focus of these firing tests was 

the interaction between the engines and the propulsion 

subsystem, as well as the performance of the pressurization 

control assembly. Engineers conducted five additional hot 

fire tests with the auxiliary engines on the PQM, as well as 

tests on the pressure control assembly valves that involved 

chilling the valves and performing multiple cycles to recreate anomalies.

Teams successfully conducted a 12-minute propulsion 

test fire to simulate an abort-to-orbit scenario in which 

the spacecraft’s service module must place Orion in a safe 

orbit if a problem were to arise after the LAS has been 

jettisoned. The test, which was the longest-ever continuous burn conducted on an OMS engine to date at White 

Sands, used the PQM to fire the OMS engine, eight auxiliary thrusters, and six reaction control system thrusters.

Acceptance Testing

At Kennedy, the Artemis I Orion crew and service modules underwent functional and performance testing in the 

high bay of the Neil Armstrong Operations and Checkout 

building, knowns as the O&C, to ensure its workmanship 

before ground processing and integration with the SLS 

rocket in the Vehicle Assembly Building.

Proof Pressure Testing

To certify that Orion could withstand the rigors of 

spaceflight, engineers completed a series of tests on the 

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pressure vessel. In a test stand inside the proof pressure 

cell, technicians attached hundreds of strain gauges to 

the interior and exterior surfaces of the structure. The 

strain gauges measured the strength of the welds as the 

pressure vessel was pressurized at incremental steps over 

two days to reach the maximum pressure it is expected 

to encounter during flight. The tests confirmed that the 

weld points would endure the extreme forces during the 

launch, in-space, entry into Earth’s atmosphere, and landing phases on Artemis missions.

Crew Module and Service Module Functional and 

Performance Testing

The Artemis I Orion crew module underwent initial 

power-on events, which was the first time the vehicle 

management computers and the power and data units 

were installed on the crew module, loaded with flight software, and tested. These tests verified the health and status 

of Orion’s core computers and power and data units; they 

also ensured that the systems were able to communicate 

precisely with one another to accurately route power and 

commands throughout the spacecraft.

The Artemis I Orion service module also separately 

underwent initial power-on tests. The tests allowed technicians to check that all cables were connected and data 

was transferred at the speeds required by Orion, as well as 

the power distribution across the module.

After initial power-on, the Orion crew module and service 

module underwent separate functional testing, which 

ensured that each of the module’s systems powered on 

and functioned as designed. After engineers completed 

functional testing, teams conducted separate performance testing of the crew module and service module. 

This testing verified that each module’s systems not only 

powered on but functioned within the correct parameters. 

Performance testing also took place after the two modules 

were joined.

Environmental Testing

Environmental testing simulates environments the spacecraft will experience through launch, travel in deep space, 

and recovery; it also evaluates the spacecraft’s structure 

and systems in those conditions. Before joining the crew 

module and service module for the Artemis I mission 

at Kennedy, engineers conducted acoustic and thermal 

cycle testing for each module separately in the high bay of 

the O&C.

• Direct Field Acoustic Testing: During this testing, 

the crew module or service module was surrounded 

with speakers and exposed to maximum acoustic levels 

that Orion will experience in space. Engineers secured 

the module inside a test cell and then attached microphones, strain gauges, and accelerometers. The module 

was blasted with extreme vibrations and acoustic levels 

up to 141 decibels—as loud as a jet engine during 

takeoff—to ensure that the spacecraft and its systems 

could withstand the noise expected during launch.

• Module Thermal Cycle Testing: Inside a specially 

constructed thermal cycle chamber, teams rapidly 

cycled the crew module or service module between hot 

and cold temperatures over several days to thermally 

stress the hardware and ensure the workmanship of the 

module’s hardware and its subsystem operations. The 

cycle of temperatures for the initial thermal test ranged 

from 29 to 129 degrees Fahrenheit during 105 hours 

of testing.

After engineers at Kennedy completed testing on the 

Artemis I crew module and service module individually, 

they were moved to the Final Assembly and System Testing 

(FAST) cell, where they were integrated and put through 

their final system tests prior to shipping to NASA’s Neil 

A. Armstrong Test Facility near Sandusky, Ohio, for three 

months of rigorous simulated in-space environmental 

testing at the world’s largest and most powerful space 

environment simulation test facility.

An international team of engineers and technicians 

completed environmental testing in two phases inside the 

Space Simulation Chamber:

• Integrated Spacecraft Thermal Balance and Thermal 

Vacuum Testing: The first phase of testing was a thermal vacuum test lasting 47 days while Orion’s systems 

were powered on under vacuum conditions that simulate the space environment. The spacecraft was subjected to extreme temperatures, ranging from minus 

250 degrees to 300 degrees Fahrenheit (minus 157 to 

149 degrees Celsius), to replicate flying in and out of 

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sunlight and shadow in space. To simulate these conditions, a specially designed piece of hardware, known as 

the Heat Flux System, was used to heat specific parts of 

the spacecraft at any given time. It was also surrounded 

on all sides by a set of large panels called a cryoshroud 

that provided the cold background temperatures of 

space. The testing ensured that Orion’s systems performed correctly in extreme flight conditions.

• Integrated Spacecraft Electromagnetic Interference/

Compatibility Testing: The second phase of testing was 

a 14-day electromagnetic interference and compatibility test. All electronic components have an electromagnetic field that can affect other electronics nearby. 

This testing ensured that the spacecraft’s electronics 

worked properly when operated at the same time, as 

well as when bombarded by external sources. The test 

campaign confirmed that the spacecraft’s systems performed as designed.

After testing in Ohio for several months, Orion was flown 

back to Florida and returned to the FAST cell at Kennedy’s 

O&C Building for a final round of testing and assembly 

that included end-to-end performance verification of the 

spacecraft’s subsystems, checking for leaks in the spacecraft’s propulsion systems, installing its solar array wings, 

performing spacecraft closeouts, and pressurizing a subset 

of its tanks in preparation for flight prior to rolling to the 

Multi-Payload Processing Facility (MPPF) for commodity 

servicing before integration with the rocket.

Structural Testing

Testing with Orion’s “structural twin” at Lockheed 

Martin’s facility in Colorado validated Orion’s structure 

and enabled engineers to push the structure past design 

standards, simulating the harsh environments that 

will physically affect the Orion spacecraft. NASA and 

Lockheed Martin built the structural test article to be 

identical to Orion’s main structural elements: the crew 

module, service module, and LAS. It did not include the 

non-structural items, such as the spacecraft computers, 

propulsion, and seats, for these tests. 

Testing involved a series of 21 tests using six different configurations—from a single element to the full stack—and 

various combinations in between. The different configurations simulated the different flight conditions—such as 

launch, return to Earth, parachute deployment, and water 

landing—that Orion will go through during a mission. 

During some test phases, engineers pushed expected pressures, mechanical loads, vibration, and shock conditions 

up to 40% beyond the most severe conditions anticipated 

during the mission, analyzing data to confirm that the 

spacecraft structures could withstand the extreme environments of space.

These tests helped to verify Orion’s design and structural 

durability for Artemis missions to the Moon.

• Pressure Testing: Pushing and pulling with pressure 

that equates to 140% of the maximum expected loads 

during missions ensured that the spacecraft structures 

could withstand intense loads at launch and reentry.

• Modal Testing: During modal testing, dynamic loads of 

pressure were applied to the spacecraft structures. With 

more than 20,000 parts making up Orion’s service 

module alone, modal tests evaluated how the spacecraft 

The Orion crew module for Exploration Mission-1 recently underwent 

Direct Field Acoustics Test, where it was exposed to maximum acoustics 

levels that the vehicle will experience in space. Spacecraft response and 

sound pressure data were collected with microphones, strain gauges, and 

accelerometers. The max decibel level was -12 dB. Image credit: NASA

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components held up to vibration, especially at connection points.

• Stiffness Testing: Stiffness testing applied pressure 

steadily and continuously to the spacecraft’s structures. 

This tested how the structures would respond to the static 

loads that the spacecraft will experience on missions.

• Acoustic Testing: Acoustic testing blasted the structures with sound waves that simulated the vibrating 

rumble of launch, reaching more than 160 decibels.

• Pyrotechnic Shock Testing: Shock tests recreated the 

powerful pyrotechnic blasts needed for separation 

events during flight, such as the LAS separating from 

the crew module after a successful launch.

• Jettison Testing: Jettison tests mimicked deployment 

mechanisms required to jettison the forward bay cover 

and ensured that components could endure the shock 

levels expected during flight.

• Lightning Testing: Lightning tests evaluated potential 

flight hardware damage that could occur if the rocket 

and spacecraft are exposed to a lightning strike prior 

to launch.

Launch Abort System Testing

Testing for Orion’s launch abort system included two 

major flight tests, along with hot fire testing for the individual motors. 

Pad Abort-1

NASA’s Pad Abort-1 test was Orion’s first major flight test 

and the first fully integrated test of the LAS. The agency 

successfully launched a test version of the crew module 

and its launch abort stack on May 6, 2010, at the U.S. 

Army’s White Sands Missile Range near Las Cruces, New 

Mexico. The flight test demonstrated the capability of the 

LAS to propel the crew module to a safe distance during a 

ground-initiated abort on the launch pad.

The test lasted about 2.5 minutes from launch until the 

test version of the crew module touched down about a 

mile north of the launch pad. The crew module reached 

a speed of approximately 445 mph in the first three seconds, with a maximum velocity of 539 mph in its upward 

A fully functional launch abort system with a test version of Orion attached launches on NASA’s Ascent Abort-2 atop a booster provided by Northrop 

Grumman on July 2, 2019, from Launch Pad 46 at Cape Canaveral Air Force Station in Florida. Image credit: NASA

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trajectory to about 1.2 miles high. The parachutes guided 

the crew module to touchdown at 16.2 mph.

Ascent Abort-2

NASA conducted the second major flight test for the 

launch abort system, known as Ascent Abort-2, on July 2, 

2019, to test the Orion LAS during ascent, which is when 

the spacecraft is expected to experience the greatest aerodynamic stress. Combined with subsystem qualification 

tests and the successful Pad Abort-1 test, this test resulted 

in a LAS that is certified to fly on the Artemis missions 

with astronauts aboard.

During the test, which lasted approximately three minutes, a booster provided by Northrop Grumman launched 

from Space Launch Complex 46 at Cape Canaveral Air 

Force Station in Florida. It carried a fully functional LAS 

and a test version of Orion to an altitude of nearly six 

miles at over 1,000 mph. At that point, the LAS’ powerful 

reverse-flow abort motor fired 400,000 pounds of thrust, 

propelling the Orion test article to a safe distance away 

from the rocket to splash down in the Atlantic Ocean. 

For cost-saving purposes, the test article was not equipped 

with parachutes, nor was the test capsule recovered from 

the ocean.

Motor Testing

Engineers have completed final qualification testing for 

each of the LAS motors—the attitude control motor, 

jettison motor, and abort motor. These tests looked at 

the maximum high- and low-temperature conditions 

that a motor might see during a launch in Florida to 

provide the data on how the motor reacts under hot or 

cold stressing conditions.

Aerodynamic, Aerothermal, and 

Aeroacoustics Testing

Engineers used wind tunnel testing and simulations to 

understand Orion’s flight behavior in Earth’s atmosphere and develop the aerodynamic, aerothermal, and 

aeroacoustics databases for Orion. The databases help to 

verify the performance, controllability, thermal protection system, structure, and safety during all phases of 

atmospheric flight, including launch aborts, by allowing 

accurate flight simulations and informing the design for 

the spacecraft.

Defining the crew module aerodynamics, both static and 

dynamic, helped to ensure stable and controllable flight 

from entry into Earth’s atmosphere to parachute deployment and descent. Similarly, defining the aerodynamics 

for the LAS helped to ensure successful launch aborts 

during ascent from the launch pad to orbit. Defining the 

aerothermal environments for the crew module and LAS 

ensured that the thermal protection systems will protect 

them from heat during atmospheric entry, ascent, and 

ascent aborts. Characterizing the aeroacoustics was also 

important in designing and testing the Orion and LAS 

structures for the vibrations and loads they will experience 

during ascent and reentry.

Teams completed more than 120 tests as part of developing the aerodynamic, aerothermal, and aeroacoustic 

databases for Orion. Teams have conducted tests in 25 

different wind tunnels, four ballistic ranges, two shock 

tunnels, and three research laboratories across the United 

States at NASA facilities in Virginia, California, and Ohio; 

Department of Defense facilities in Tennessee, Maryland, 

and Florida; and universities such as the University of 

Buffalo in New York. The tests have covered speeds from 

38 mph to about 15,000 mph.

Parachute Testing

NASA has fully qualified the parachute system for flights 

with crew through an extensive series of 17 developmental 

tests and eight qualification tests at the U.S. Army’s Yuma 

Proving Ground in Arizona.

During the development series, engineers tested different 

types of failure scenarios and extreme descent conditions 

to refine Orion’s parachute design and ensure that the 

parachutes will work in a variety of circumstances. 

During the qualification testing, engineers evaluated 

the performance of the parachute system during normal 

landing sequences as well as several failure scenarios 

and a variety of potential aerodynamic conditions to 

ensure that astronauts can return safely from deep 

space missions.

While airdrop testing was a vital, and very visible, component to the development of Orion’s parachutes, ground 

testing and analysis were equally important to ensuring 

success. Airdrop testing cannot physically reach all possible 

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Orion Spacecraft > Testing

spaceflight deployment conditions, but its data helped 

generate computer models of parachute performance and 

allowed the team to evaluate the parachutes in altitude 

and airspeed regimes that could not be thoroughly drop 

tested. Repeated simulation of the parachutes with varied 

parameters, called the Monte Carlo method, allowed the 

team to estimate the bounds of what parachute loads and 

performance should be expected throughout the life of the 

program. Ground testing of material capabilities, coupled 

with the parachute simulations, determined how much 

structural margin exists in the system. This combination 

of ground tests, airdrop tests, and analysis qualified the 

system for Artemis flights with astronauts.

Crew Module Uprighting System 

Testing

Engineers tested the crew module uprighting system, 

or CMUS, as part of Orion’s first flight test and implemented a series of design changes to improve its performance. During EFT-1, three of the system’s five bags did 

not properly inflate. The spacecraft landed and remained 

upright in the water; however, had the capsule landed 

upside down, the two functioning CMUS bags would 

likely not have been able to fully upright the capsule. 

Design improvements included thickening the inner 

bladder of each bag to make it more durable, changing 

how the bags are packed, developing a hard enclosure for 

the packed bags, and improving manufacturing processes 

for better control and consistency.

Engineers also performed several full-scale uprighting 

tests with a mock-up of the Orion crew capsule. These 

tests demonstrated that the CMUS would perform as 

intended, including if any one of the five uprighting bags 

were to fail to inflate. This process included seven tests 

in the calm water of the Neutral Buoyancy Lab, a giant 

pool at NASA’s Johnson Space Center primarily used for 

astronaut training. The teams also successfully completed 

two tests off the coast of Galveston, Texas, in cooperation 

with the U.S. Coast Guard Cutter Cypress, Air Force personnel, and Texas A&M Galveston. Teams completed an 

additional four tests in the Atlantic Ocean, off the coast 

of Atlantic Beach, North Carolina, in cooperation with 

the U.S. Coast Guard Station Fort Macon and the U.S. 

Coast Guard Cutter Maple. These tests demonstrated 

performance in a natural wave environment and were 

instrumental in the certification of the CMUS. 

Water Impact Testing

Teams conducted water-impact testing at NASA’s Langley 

Research Center in the center’s Hydro Impact Basin at 

the Landing and Impact Research Facility to provide 

high-fidelity data of the forces that the Orion spacecraft 

structure and its astronaut crew would experience during 

landing, helping to protect the crew and informing future 

designs. Water-impact testing evaluates how the spacecraft 

may behave in parachute-assisted landings in different 

wind conditions and wave heights. 

Engineers used three different test versions of Orion as 

the spacecraft’s design was refined over the course of 

the test series. The final series of drop tests used the test 

article previously used for structural testing at Lockheed 

Martin’s facility in Colorado, which was based on the final 

design for the configuration that will fly on Artemis II. 

Teams will use data from the drop tests as well as from the 

upcoming Artemis I flight test in final computer modeling for loads and structures prior to Artemis II.

Avionics and Software Testing

The Orion program uses a network of integrated test labs 

designed to reduce cost and schedule risk by providing 

an early opportunity in the development phase of the 

program to perform systems-level avionics and software 

testing for Orion in a realistic environment.

Engineers used Lockheed Martin’s state-of-the-art facility called the Exploration Development Laboratory in 

Houston for this testing, including avionics system testing 

to reduce risk prior to the Pad Abort-1 test and Exploration 

Flight Test-1. Initial testing of systems also included the 

guidance, navigation, and control, as well as automated 

rendezvous and docking, and crew interfaces. Engineers 

also used the facility to perform early development, integration, and dry-run testing of Orion avionics hardware 

Workers check the pressure of the bright orange stabilizers that will keep 

Orion upright in the water if needed. NASA, Lockheed Martin, and the U.S. 

Navy are conducting the test in the Pacific Ocean off the coast of San Diego. 

Image credit: NASA

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and software and associated internal and external crew 

module interfaces using flight-representative software and 

an appropriate suite of ground support tools, systems, 

and software.

Lockheed Martin’s Orion Integrated Test Lab, or ITL, 

located near Denver, runs full mission scenarios from prelaunch to landing, or specific phases of the flight. The lab 

uses a full-size Orion mockup with a fully integrated set of 

Orion’s crew module and service module avionics, power, 

wiring, guidance, navigation, and control hardware. The 

lab’s systems connect to the MCC, which allow for realtime monitoring and commanding of the spacecraft in 

Houston in order to simulate the Artemis I mission.

Tests performed in the ITL are essential for identifying 

software problems and validating proper functionality 

and performance of the spacecraft avionics system.

An ITL configuration is the highest-fidelity test platform 

that Orion avionics hardware and software would experience prior to actual testing regimens on the assembled 

spacecraft, providing as close to a “test like you fly” environment as can be assembled within a lab setting.

Flight Control Team Training 

and Testing

The flight control team began training for the Artemis I 

mission in 2019 and will continue in the weeks prior to 

launch. They constantly refine and practice procedures 

they will use on the ground to monitor, command, and 

control Orion. Flight controllers in the MCC prepare by 

simulating various parts of Orion’s journey, from launch 

through outbound powered flyby to the Moon, including 

the trans-lunar injection burn that sends the spacecraft 

out of Earth orbit and toward the Moon. The MCC also 

simulates Orion’s orbit around the Moon and return powered flyby from the Moon through entry, descent, landing, 

and recovery, including the final trajectory corrections 

Teams conduct a vertical drop test of an Orion test article as part of water-impact testing at the Hydro Impact Basin at Langley’s Landing and Impact 

Research Facility. Image credit: NASA

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Orion Spacecraft > Management Roles and Facilities

and burns Orion will need to enter the atmosphere and 

splash down in the Pacific Ocean.

Simulations and testing have included joint operations 

between industry partners and NASA’s flight operations 

team, with NASA doing real-time monitoring and commanding of the simulated version of Orion at the ITL 

in Denver from the MCC in Houston. Testing has also 

been done with a low-fidelity Orion mockup and with the 

actual Orion spacecraft at the Exploration Development 

Lab in Houston.

Engineers also tested the Orion communications system to 

ensure that the spacecraft and the MCC could flawlessly 

communicate and send data through NASA’s satellite networks in space and on the ground. The MCC verified that 

these communication systems work with Orion during tests 

of different Artemis I scenarios from launch to landing.

Management Roles and Facilities

Armstrong Flight Research Center

Armstrong Flight Research Center has supported Orion’s 

flight testing in preparation for Artemis I. Armstrong was 

the developmental flight instrumentation (DFI) lead for 

Ascent Abort-2 and supported flight test development and 

system integration, ground operations definition, planning, and personnel; it also provided component testing. 

The team also led test vehicle integration and DFI for the 

Pad Abort-1 (PA-1) flight test and was the integrated product team lead for construction of the flight’s launch site. 

Armstrong also led the Ikhana remotely piloted aircraft 

that was used to capture live video during the Orion entry 

and landing for Exploration Flight Test-1. The center also 

supported Orion’s Capsule Parachute Assembly System 

(CPAS) during parachute qualification testing.

Goddard Space Flight Center

Goddard Space Flight Center supports Orion communication and navigation operations through NASA’s Near Space 

Network (NSN), including a constellation of Tracking 

and Data Relay Satellites (TDRS) and associated ground 

stations. The center also provides tracking and navigation 

support with its Flight Dynamics Facility. 

Goddard supports the NASA Communications Network 

(NASCOM), which carries command and telemetry data 

and provides mission-critical voice loops between ground 

stations, mission control centers, and other ground segments. The Goddard team also supports NASA’s Search 

and Rescue office, which provides the responsive location 

services for Orion crew recovery.

Jet Propulsion Laboratory

The Jet Propulsion Laboratory supports Orion systems 

engineering and integration. The team also provides 

independent validation of Orion’s thermal protection 

system and parachutes and provides advanced spacecraft 

environmental monitoring.

Johnson Space Center

NASA’s Orion program is managed at Johnson, where 

engineers oversee the design, development, and testing 

of the spacecraft, as well as spacecraft manufacturing 

taking place across the country and in Europe. Johnson 

is also home to the nation’s astronaut corps and the iconic 

Christopher C. Kraft Mission Control Center.

Mission Control Center (MCC)

Since 1965, NASA’s MCC has been the helm of America’s 

human spaceflight and is the primary facility where flight 

controllers command and control human spacecraft missions. MCC is the facility from which flight operations 

personnel will remotely monitor and operate the Orion 

spacecraft and receive data from Orion and the SLS rocket 

during Artemis missions. 

The MCC is composed of several flight control rooms 

(FCRs), including FCR-1; FCR-2; and the Red, White, 

and Blue FCRs. Johnson upgraded the White FCR from 

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Orion Spacecraft > Management Roles and Facilities

its shuttle legacy configuration into a modern mission 

control configuration to serve as the mission control for 

flights of NASA’s Orion spacecraft.

White Sands Test Facility

NASA’s White Sands Test Facility in New Mexico is a 

component of Johnson that tests and evaluates potentially 

hazardous materials, spaceflight components, and rocket 

propulsion systems for NASA centers, other government 

agencies, and commercial industry. This work includes 

testing Orion’s service module, the powerhouse of the 

spacecraft that provides in-space propulsion, power, and 

other astronaut life-support systems, including consumables like water, oxygen, and nitrogen.

Kennedy Space Center

Neil Armstrong Operations and Checkout 

(O&C) Building

When the Artemis I Orion spacecraft arrived at Kennedy 

following initial manufacturing at Michoud Assembly 

Facility in New Orleans, it was placed in the O&C building. The O&C contains a large room called a high bay that 

operates as a high-tech factory, and it was there that the 

spacecraft was assembled and readied for Artemis I. The 

high bay includes unique tooling stations, test fixtures, 

chambers, and clean rooms for the buildup and testing of 

the spacecraft. 

The facility is capable of processing multiple spacecraft in 

varying production phases. Orion spacecraft for EFT-1 and 

Artemis I have been completed in the O&C with the assembly of spacecraft for future Artemis missions well underway.

Marshall Space Flight Center

More than 1,500 parts for the spacecraft have been 

fabricated in Marshall’s machine shop, including clips, 

sleeves, and rod ends used for unique connections on 

the Orion spacecraft. Marshall assists Orion’s European 

Service Module (ESM) Integration Office by providing 

Orion isolation valve refurbishment and Orion gas valve 

seat material testing, as well as support for Orion’s service 

module propulsion systems with subsystem-level hot fire 

test operations, along with data review.

Other contributions include support related to space and 

terrestrial environments, including radiation, plasma, sea 

states, atmosphere, and winds; and plume and aerothermodynamic analysis and consultation.

The LAS integration and transition to production operations is managed by Marshall with Lockheed Martin as 

the lead contractor. Marshall also provides fabrication, 

production, and assembly support to NASA teams across 

the Orion Program. This effort includes the integration of 

Orion and the SLS rocket.

Michoud Assembly Facility

Michoud is a component of Marshall where manufacturing and assembly of some of the largest parts of the Orion 

spacecraft, including Orion’s pressure vessel, take place. 

The work done at Michoud includes the production and 

welding of the Orion crew module pressure vessel structure, the production of the crew module adapter structure, 

the production of heat shield block material and composite 

panels, the production of service module fairings, and the 

assembly and integration of LAS structural components.

Langley Research Center

Landing and Impact Research Facility

Engineers performed water impact testing on Orion at 

the Hydro Impact Basin at Langley’s Landing and Impact 

Research Facility. The water basin is 115 feet long, 90 feet 

wide, and 20 feet deep. The basin is located at the west 

end of the gantry, which is a 240-foot-high, 400-footlong, 265-foot-wide A-frame steel structure. The gantry 

provides the ability to control the orientation of the test 

article while imparting a vertical and horizontal impact 

velocity, which is required for human-rating spacecraft.

Glenn Research Center

Glenn serves as the lead for ESA/Airbus integration and 

management. It also leads in spacecraft mechanisms, 

pyrotechnics, and structures. Furthermore, the center is 

a co-lead for the crew and service module and spacecraft 

adapter. It also provides support for spacecraft integration; 

test and verification; avionics, power and wiring subsystems; and software and Guidance Navigation & Control.

Neil A. Armstrong Test Facility

Neil A. Armstrong Test Facility, formerly known as Plum 

Brook Station, is a remote test facility near Sandusky, 

Ohio, and home to four world-class test facilities, which 

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Orion Spacecraft > Management Roles and Facilities

perform complex and innovative ground tests for the 

international space community. Engineers conducted 

major tests for the Orion spacecraft at the facility’s 

Space Environments Complex, which houses the world’s 

largest and most capable space environment simulation 

facilities. These include the Space Simulation Chamber, 

which simulates the thermal and vacuum conditions of 

space and provides an environment in which to test electromagnetic interference; the Reverberant Test Facility, 

a 100,000-cubic-foot reverberant acoustic chamber; and 

the Mechanical Vibration Facility, a vibration table capable of testing an entire spacecraft in all three axes.

Ames Research Center

Ames has contributed to a variety of testing and development activities for the Orion spacecraft. Engineers at 

Ames helped develop and test materials for Orion’s heat 

shield and cone-shaped back shell using Ames’ Arc Jet 

Complex under various heating and pressure environments selected to simulate flight conditions. Using Ames’ 

Unitary Plan Wind Tunnel, teams also tested models of 

Orion at supersonic air speeds. Additionally, researchers 

at Ames used supercomputing capabilities to predict and 

better understand how different abort scenarios—from 

the launchpad to the edge of space—will affect vibration 

levels on the spacecraft.

Industry and International Partners

Lockheed Martin

Lockheed Martin is the lead contractor for the design, 

development testing, and production of the Orion spacecraft for NASA’s Artemis missions. As lead contractor for 

Orion, Lockheed Martin manufactures the spacecraft’s 

crew module, LAS, and crew module adapter. The 

company also integrates Orion’s service module into a 

completed spacecraft. Lockheed Martin’s Orion Program 

Office is based in Houston, where teams conduct Orion 

engineering and design. The team performs the majority 

of the Orion engineering work in Denver, manufactures 

the crew module pressure vessel and thermal protection 

materials at Michoud, and completes final assembly of 

the spacecraft in the O&C at Kennedy and at Lockheed 

Martin’s Spacecraft, Test, Assembly and Resource 

Center nearby.

Northrop Grumman

Northrop Grumman produces the launch abort motor 

and the attitude control motor for the Orion spacecraft’s 

LAS under an agreement with Lockheed Martin. The 

abort motor is manufactured at the company’s facilities in 

Magna, Promontory, and Clearfield, Utah, and the attitude control motor is produced at the company’s facility 

in Elkton, Maryland.

Aerojet Rocketdyne

Aerojet Rocketdyne provides eight auxiliary engines and 

12 reaction control thrusters for the Orion crew module 

as well as the jettison motor for the LAS, under contract 

to Lockheed Martin. The company also manufactures the 

high-pressure helium tanks that inflate Orion’s flotation 

system for water-based landings. Orion’s auxiliary engines 

and reaction control thrusters are produced at Aerojet 

Rocketdyne’s facility in Redmond, Washington. The jettison motor is a combined effort of the company’s facilities 

in Orange, Virginia, and Huntsville, Alabama.

Aerojet Rocketdyne will also develop the Orion main 

engine that will be integrated into Orion’s service module 

on Artemis missions VII through XIV, replacing the 

Orbital Maneuvering System Engine repurposed from 

the Space Shuttle Program, also manufactured by Aerojet 

Rocketdyne.

European Space Agency and Airbus

Orion’s European Service Module is provided by ESA 

and built by main contractor Airbus. Workers across 

10 European countries and the United States supply 

components for the service module, including Germany, 

Italy, Switzerland, France, Belgium, Sweden, Denmark, 

Norway, Spain, and the Netherlands. The final product is 

assembled at Airbus facilities in Bremen, Germany, before 

being shipped to NASA.

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Orion Spacecraft > Quick Facts

Quick Facts 

Orion Summary

Gross liftoff 

weight 

72,000 lb (32,650 kg)

Trans-lunar 

injection mass

53,000 lb (24,050 kg)

Post-trans lunar 

injection mass

51,500 lb (23,850 kg)

Usable propellant 16,000 lb (7, 250 kg)

Launch Abort System

Height 50 ft from LAS tip to LAS/SM interface, with ogive 

panels

Diameter 3 ft (1 m) at tower

17 ft (5.2 m) at base 

Liftoff weight 16,700 lb (7,600 kg)

Propellant weight 5,700 lb (2,600 kg)

Abort motor 

weight

7,600 lb (3,450 kg)

includes 4,700 lb (2,100 kg) of propellant

400,000 lb (181, 400 kg) of peak thrust

Attitude motor 

weight

1,700 lb (750 kg)

includes 650 lb (300 kg) of propellant

7,000 lb (3,200 kg) of thrust

Jettison motor 

weight

900 lb (400 kg)

includes 350 lb (150 kg) of propellant

40,000 lb (18,100 kg) of thrust

Crew Module (Crew and Cargo Transport)

Height 11 ft (3.3 m)

Diameter 16.5 ft (5 m)

Pressurized 

volume (total)

690.6 ft3

 (19.5 m3)

Habitable volume 

(net)

316 ft3

 (9 m3)

Reaction control 

system vacuum 

engine thrust

160 lbf (75 kgf)/engine

Return payload 220 lb (100 kg)

Landing weight 18,200 lb (8,250 kg)

Gross liftoff 

weight

20,600 lb (9,350 kg)

Service Module (Propulsion, Electrical Power, Fluid 

Storage)

Length 15.7 ft (4.75 m)

Diameter 16.5 ft (5 m)

Gross liftoff 

weight

30,900 lb (14,000 kg)

Engines/thrusters 24 reaction control system thrusters

50 lb (23 kg) of thrust each

8 auxiliary engines

110 lb (50 kg) of thrust each

1 Orbital Maneuvering System

6,000 lb (2,700 kg) of thrust

Solar arrays 4 arrays

15,000 solar cells

62 ft (19 m) when deployed

11 kW of regenerable electrical power

Spacecraft Adapter

Weight of spacecraft adapter 

jettisoned fairings

2,800 lb (1,300 kg)

Weight of spacecraft adapter 1,000 lb (450 kg)

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Orion Spacecraft > Quick Facts

Parachutes

Three Forward Bay Cover Parachutes

Diameter 7 ft (2.15 m)

Length 100 ft (30 m)

Weight 8 lb (3.5 kg) each

Material All Kevlar materials

Deployment 

altitude

26,500 ft (8,000 kg)

Deployment speed 475 ft (145 m) per second (324 mph) (520 kph)

Density Approx. 49 lb (785 kg) per ft3

 (roughly the same 

as oak)

Final packed size 7.2-in by 6.9-in (18-cm by 17-cm) (0.16-ft3

) 

(.005 m3

) cylinder

Two Drogue Parachutes

Diameter 23 ft (7 m)

Length 100 ft (30 m)

Weight 60 lb (27 kg) each

Material Kevlar and nylon materials

Deployment 

altitude

25,000 ft (7,600 m)

Deployment speed 450 ft (140 m) per second (307 mph) (500 kph)

Density Approx. 40 lb (640 kg) per ft3

 (roughly the same 

as oak)

Final packed size 16.5-in by 16.2-in (42-cm by 41-cm) (2-ft3

) 

(.06 m3

) cylinder

Three Pilot Parachutes

Diameter 10 ft (3 m)

Length 70 ft (21 m)

Weight 9 lb (4 kg) each

Material Kevlar and nylon materials

Deployment 

altitude

9,500 ft (2, 895 m) altitude

Deployment speed 190 ft (58 m) per second (130 mph) (81 kph)

Density Approx. 35 lb (560 kg) per ft3

 (roughly the same 

as pine)

Final packed size 6.8-in by 13.3-in (17-cm by 34-cm) (0.3-ft3

) 

(.008 m3

) cylinder

Three Main Parachutes

Diameter 116 ft (35 m)

Length 220 ft (67 m)

Weight 270 lb (120 kg) each

Material Kevlar and nylon materials

Deployment 

altitude

9,000 ft (2,750 m)

Deployment speed 190 ft (60 m) per second (130 mph) (210 kph)

Density Approx. 44 lb (700 kg) per ft3

 (roughly the same 

as oak)

Final packed size Approx. 7 ft3

 (.2 m3); irregular shape to fit into the 

Orion forward bay

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ARTEMIS REFERENCE GUIDE

SLS and Orion 

Livery and External 

Markings

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SLS and Orion Livery and External Markings > Orion Summary

ARTEMIS REFERENCE GUIDE

In addition to the SLS core stage’s distinctive orange color, 

several other markings are visible on the outside of the 

rocket and Orion spacecraft.

The most visible are the national and agency livery, or 

distinctive exterior markings, such as “USA,” the U.S. 

flag, the NASA insignia known as the “meatball” or the 

logotype known as the “worm,” and the ESA mark.

SLS, Orion, and the mobile launcher also have black-andwhite markings that play an important role in Artemis I. 

Called photogrammetric markings, the black-and-white 

checkerboards, squares, and circles on the outside of the 

rocket serve as imagery references for engineering photo 

and video documentation of SLS attitude and position 

relative to ground structure during liftoff and ascent. 

Markings range in size from 0.2 inches to 3 by 3 feet. 

Multi-checkered pattern markings on the solid rocket 

boosters measure 24 by 130 inches.

Some of the markings are visible only to internal cameras and will capture separation and jettison events. The 

launch vehicle stage adapter has eight internal markings; 

the interim cryogenic propulsion stage (ICPS) has 12; 

the forward bay of Orion’s service module has 30; the 

spacecraft adapter has 12; and spacecraft adapter jettison 

panel 1 has 12 markings.

Engineers are interested in every movement of the rocket, 

in every phase of flight, from the launch pad to its return 

to Earth. Most of the markings will be used during 

separation events, such as SLS from the mobile launcher, 

boosters from the core stage, core stage and launch vehicle 

stage adapter from the ICPS, and ICPS and Orion stage 

adapter from Orion and its service module.

The markings help to characterize these movements, and 

the data will feed back into computer models to help engineers understand actual vs. predicted movements. Every 

key launch event and its marking were analyzed for placement. Key considerations were where to place on-board 

cameras to survive the harsh launch environment, as well 

as ground camera locations.

Livery and Photogrammetric 

Markings

The Orion spacecraft is adorned with several distinctive 

external markings for the Artemis I mission. The NASA 

insignia, known as the “meatball,” appears along with 

the ESA logo on the spacecraft adapter jettison fairing 

panels that will be visible from the launch pad and protect 

the service module during launch. The NASA logotype, 

referred to as the “worm,” is painted on the outboard 

wall of the spacecraft’s crew module adapter and will be 

visible both on the pad and in space. The worm and ESA 

logo will also appear on the underside of the crew module 

adapter but will be visible only while Orion is in space. The 

NASA meatball and an American flag are also painted on 

the exterior of the crew module and will be visible while 

Orion is in space and may be visible when Orion returns 

to Earth after its blazing reentry through the atmosphere.

Orion hardware will also include photogrammetric 

markings that serve as imagery references for engineering 

photo and video documentation during liftoff and ascent 

in addition to those on the SLS rocket.

Cameras

SLS and Orion have several cameras on the rocket, as well 

as inside and outside the spacecraft, that will gather engineering pictures and video to inspect systems and capture 

imagery during the mission. 

SLS has a total of eight cameras, with four on the engine 

section that look upward, two on the intertank looking 

toward the bottom of the rocket, and two inside the launch 

vehicle stage adapter to capture the ICPS separation event. 

Orion has seven external cameras and five cameras inside 

The NASA logotype, or “worm” logo, and ESA logo are seen in this 

illustration of the Orion spacecraft in space near the Moon on the Artemis I 

mission. Image credit: NASA

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SLS and Orion Livery and External Markings > Orion Summary

ARTEMIS REFERENCE GUIDE

the spacecraft. Each of the solar array wings has a wireless camera near the tip that can be pointed to inspect 

the exterior of the spacecraft, as well as three cameras 

mounted on the crew module adapter—two point toward 

the service module at different angles, and one points 

upward toward the crew module inside the crew module 

adapter to capture separation prior to reentry. Three 

cameras are mounted inside Orion to capture views from 

inside and outside the crew module, with one looking out 

the top docking hatch window, one looking out the front 

pilot window, and one mounted between the pilot seats 

looking at where the instrument panel will be located on 

future missions. Two additional exterior cameras face the 

forward bay cover.

In addition to the cameras on SLS and Orion, there are 

more than 150 ground cameras used for inspecting or 

monitoring the rocket during launch.

 Technicians with lead solid rocket boosters contractor Northrop Grumman paint photogrammetric markings on one segment of an SLS solid rocket motor. 

The NASA “worm” livery and black-and-white photogrammetric 

markings are visible on completed solid rocket motor segments. Image 

credit: NASA

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Exploration Ground Systems > Orion Summary

ARTEMIS REFERENCE GUIDE

Exploration 

Ground Systems

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Exploration Ground Systems > Introduction

ARTEMIS REFERENCE GUIDE

Introduction

The Exploration Ground Systems (EGS) program is helping to build a diverse future in spaceflight at Kennedy, 

which has served as the nation’s gateway to exploring the 

universe for more than 50 years. Taking the knowledge 

and assets of NASA’s successful spacefaring past, EGS’ 

mission is to transform the center from a historically 

government-only launch complex to a spaceport that can 

handle several different kinds of spacecraft and rockets—

both government and commercial.

Unlike previous work focusing on a single rocket or 

spacecraft, such as the Saturn V or space shuttle, EGS is 

preparing the infrastructure to support several different 

spacecraft and rockets, including the SLS rocket and 

the Orion spacecraft for Artemis I. A key aspect of the 

program’s approach to long-term sustainability and affordability is to make processing and launch infrastructure 

available to commercial and other government customers, 

thereby distributing the cost among multiple users and 

reducing the cost of access to space.

HELPFUL RESOURCES

For more information about Exploration Ground Systems

(EGS), visit https://www.nasa.gov/groundsystems

SOCIAL MEDIA

Twitter: https://www.twitter.com/NASAGroundSys

Facebook: https://www.facebook.com/

NASAGroundSystems

A view of the Vehicle Assembly Building at NASA’s Kennedy Space Center during sunrise on Jan. 19, 2022, with the SLS rocket and Orion spacecraft for 

the agency’s Artemis I mission stacked inside. Image credit: NASA

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ARTEMIS REFERENCE GUIDE

Overview

EGS was established to develop and operate the systems 

and facilities necessary to process, assemble, transport, and 

launch rockets and spacecraft. Jacobs is the lead ground 

and launch operations contractor for EGS at Kennedy, 

conducting all Artemis I flight hardware acceptance, processing, stacking, integration, testing, and launch support. 

For Artemis missions, EGS is focusing on the equipment, 

management, and operations required to safely connect 

the Orion spacecraft with the SLS rocket; move the rocket 

to the launch pad; successfully launch it into space; and 

recover the spacecraft once it has splashed down. To 

meet this challenge, EGS upgraded Launch Pad 39B, 

the crawler-transporters, the 52-story Vehicle Assembly 

Building (VAB), the Launch Control Center’s YoungCrippen Firing Room 1, and other facilities.

Future Missions and Configurations

Following the uncrewed Artemis I mission, EGS will 

continue upgrades to support crewed missions with the 

Block 1 configuration of the SLS rocket for Artemis II 

and III. Launch Pad 39B is ready for Artemis I, and a new 

liquid hydrogen tank and emergency egress system at the 

pad will support Artemis II, the first crewed launch. The 

new liquid hydrogen tank will hold about 1.25 million 

gallons of usable liquid hydrogen propellant to support 

the SLS rocket and is the largest tank ever built for NASA. 

The emergency egress system will provide an escape path 

for the astronauts and ground crew in the unlikely event 

of an extremely hazardous situation at the level of the crew 

access arm on the mobile launcher. 

Following Artemis III, NASA will build a second mobile 

launcher, also known as ML2, to support the SLS Block 1B 

and Block 2 configurations. The next SLS configurations 

will use the exploration upper stage, which will replace 

the ICPS as the rocket’s upper stage, allowing NASA to 

An aerial view of Launch Complex 39B with 

Exploration Ground Systems’ mobile launcher for the 

Artemis I mission on the pad. Image credit: NASA

...the Exploration 

Ground Systems 

(EGS) program is 

helping to build a 

successful and diverse 

future in spaceflight.

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ARTEMIS REFERENCE GUIDE

Exploration Ground Systems > Elements

send astronauts and heavy cargo to the Moon on a single 

launch. The ML2 will accommodate the new upper stage 

and structural adapters that increase the height of SLS on 

the more powerful configurations. Although the next SLS 

configurations will be about 40 feet taller than Block 1, 

the tower of the second mobile launcher is planned to be 

only about seven feet taller than the first mobile launcher 

to fit in the VAB and on Launch Pad 39B. However, wind 

will have a greater effect on the taller configurations of the 

rocket and impart higher loads on the mobile launcher. 

In addition, select swing arms and interfaces must be 

located at different elevations for ML2 to accommodate 

the height increase, and the new upper stage also requires 

different interfaces from those with ML1, as well as two 

new swing arms.

Elements

Launch Complex 39

Launch Complex 39 consists of the VAB for final assembly 

and testing of the rocket and spacecraft; a crawlerway used 

by the crawler-transporter that will carry the rocket on top 

of the mobile launcher between the VAB and the pad; the 

Launch Control Center, which contains the firing rooms 

for commanding the launch; various operational support 

buildings; and launch sub-complexes for separate launch 

pads, which include 39A and 39B—with Launch Pad 

39B supporting SLS launches to send Orion on Artemis 

missions to the Moon.

Vehicle Assembly Building

One of the largest buildings in the world by volume, the 

VAB covers eight acres and is 525 feet tall and 518 feet 

wide. The VAB was constructed for the assembly of the 

Apollo Saturn V Moon rocket, the largest rocket made by 

humans at the time. It is made up of 65,000 cubic yards 

of concrete, and its frame is constructed from 98,590 

tons of steel. It stands atop a support base of 4,225 steel 

pilings driven 164 feet into bedrock. The last structural 

beam was positioned in the VAB in 1965. The interior 

construction, including the construction of the extensible 

work platforms, was completed in 1966. The building is In this view looking up in High Bay 3 of the VAB at NASA’s Kennedy 

Space Center on Mar. 16, 2022, all of the work platforms that surround the 

Artemis I SLS and Orion spacecraft are fully retracted. Image credit: NASA

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Exploration Ground Systems > Elements

ARTEMIS REFERENCE GUIDE

located 3.5 miles from Launch Pad 39A and 4.2 miles 

from Launch Pad 39B.

The iconic facility serves as the central hub of NASA’s 

premier multi-user spaceport, capable of hosting several 

different kinds of rockets and spacecraft at the same time. 

Whether the rockets and spacecraft are going into Earth 

orbit or being sent into deep space, the VAB will have the 

infrastructure to prepare them for their missions.

The tallest portion of the VAB is called the high bay. 

There are four high bays, two on the east side and two on 

the west side of the building. Each has a 456-foot-high 

door, enabling rockets to be stacked vertically and then 

rolled out to the launch pad. The high bay doors are the 

largest in the world and take about 45 minutes to open or 

close completely.

There are five overhead cranes inside the VAB, including 

two that can hold 325 tons. Operated from cabs near the 

VAB’s ceiling, the cranes are precise enough to lower an 

object onto an egg without cracking it.

NASA removed the shuttle-era work platforms and 

installed ten levels of new work platforms, 20 platform 

halves altogether, in high bay 3 to surround the SLS rocket 

and the Orion spacecraft for access during processing for 

Artemis missions. Several miles of Apollo- and shuttle-era 

abandoned copper and lead-shielded cabling also were 

removed to make room for the installation of state-ofthe-art command, communication, and control systems 

needed to perform testing and verification prior to rollout 

to the launch pad.

Platforms A–K

Each of the giant steel platforms measures about 38 feet 

long and 62 feet wide, weighing between 300,000 and 

325,000 pounds. The platforms are attached to rail beams 

that provide structural support and contain the drive 

mechanisms to retract and extend them. Each platform 

rides on four Hillman roller systems that are located 

two on each side—much like a kitchen drawer glides in 

and out.

• Platform A (346 feet above the VAB floor) provides 

access to the Orion spacecraft’s LAS for Orion Lifting 

Sling removal and installation of the closeout panels. 

LAS Antenna Testing (Antenna Hat installation for 

testing) is also performed at this level.

• Platform B (311 feet above the VAB floor) provides 

access to the Orion Service Module Umbilical and has 

emergency egress stairs from the Crew Access Arm 

White Room.

• Platform C (280 feet above the VAB floor) provides 

access to the Orion stage adapter and the ICPS. 

Engineers use this level for operations to join the ICPS 

with the launch vehicle stage adapter and also with the 

ICPS umbilical. Platform C also makes it possible to 

open the LVSA upper access doors for entry to the top 

of ICPS.

• Platform D (264 feet above the VAB floor) makes it 

possible to open the LVSA lower access doors for entry 

to the ICPS to perform flight battery and computer 

installation on the ICPS equipment shelf.

• Platform E (246 feet above the VAB floor) provides 

access to the core stage forward skirt umbilical. 

Engineers use an elevated access platform on this 

level for operations to join the LVSA and core stage. 

Entry into the core stage forward skirt is necessary 

to access components of the rocket’s avionics for 

verification operations.

 Teams at NASA’s Kennedy Space Center participated in the first joint 

integrated launch countdown simulation for Artemis I inside Firing Room 1 

of the Launch Control Center on July 8, 2021. Seen at the top of the room 

is Charlie Blackwell-Thompson (right), the launch director for Artemis  I. 

The training exercise involved engineers from Kennedy, Marshall, and 

Johnson coming together to rehearse all aspects of the launch countdown. 

Image credit: NASA

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ARTEMIS REFERENCE GUIDE

Exploration Ground Systems > Elements

• Platform F (192 feet above the VAB floor) provides access 

to the core stage intertank and the core stage intertank 

umbilical. Engineers use the multi-level ground support 

equipment access platform, referred to as F-1, on this 

level for access to the booster forward assemblies and 

the core stage to booster forward attach points. The 

upper level of F-1 is used for lifting sling removal during 

booster stacking to join the forward assembly.

• Platform G (166 feet above the VAB floor) provides 

access for booster segment stacking operations of the 

forward segment to the forward center segment and 

booster systems tunnel cable routing and closeouts.

• Platform H (139 feet above the VAB floor) provides 

access to the booster segment for operations to join the 

forward center segment to the center segment, as well 

as booster systems tunnel cable routing and closeouts.

• Platform J (112 feet above the VAB floor) provides 

access for operations to join the center booster segment 

to the aft center segment, as well as booster systems 

tunnel cable routing and closeouts.

• Platform K (86 feet above the VAB floor) provides 

access for booster segment stacking operations of the 

aft center segment to the booster aft assembly and 

booster systems tunnel cable routing and closeouts. 

Level K-1 is installed under the platform for access to 

the core stage and lower booster attach points.

Launch Pad 39B

NASA has upgraded Launch Pad 39B from its previous 

uses under Apollo and the Space Shuttle Program to 

support the SLS rocket and other potential users. The 

guiding principle behind the upgrades and modifications 

has been to make the area a “clean pad,” which will allow 

a variety of rockets to launch from the pad. The basics that 

all rockets need, such as electrical power, a water system, 

a flame trench, and a safe launch area, are in place. The 

other needs of individual rockets, including access for 

 Standing atop the mobile launcher, NASA’s Space Launch System (rocket and Orion spacecraft) can be seen at Launch Pad 39B at Kennedy Space Center 

on Mar. 18, 2022. Image credit: NASA

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workers, can be met with the towers or other structures 

that deliver the rocket to the pad.

During refurbishment projects, teams replaced 1.3 million feet of copper cables with 300,000 feet of fiber cable, 

installed new bypass lines and valves, removed the heritage liquid oxygen vaporizer, installed a liquid hydrogen 

separator vaporizer, replaced the heritage environmental 

control system equipment, and replaced the fire suppression piping around the entire pad complex. The vaporizers 

convert the liquid oxygen or hydrogen into gas, which 

then is fed back into the tank to pressurize it to begin the 

flow to the rocket.

Launch Pad Systems and Elements

Sound Suppression System

The purpose of the sound suppression system is to dampen 

sound, vibrations, and extreme heat during liftoff to keep 

the rocket and the launch pad safe. The water tower for 

the Ignition Overpressure and Sound Suppression System 

holds roughly 400,000 gallons of water, or enough to fill 

27 average swimming pools. At ignition and liftoff, this 

water is dumped on the mobile launcher and inside the 

flame trench in less than 30 seconds. The peak flow rate 

is 1.1 million gallons per minute, high enough to empty 

roughly two Olympic-size swimming pools in one minute. The water tower was sandblasted and repainted so it 

can continue to withstand the corrosive salt air from the 

nearby Atlantic Ocean.

Flame Trench

The flame trench contains a flame deflector to safely divert 

the exhaust plume from the SLS rocket during launch. 

The refurbished flame trench is 450 feet long—the size 

of one and a half football fields—and the new flame 

deflector will experience a peak temperature of 2,200 

degrees Fahrenheit (1,204 degrees Celsius) during launch. 

Teams removed Apollo-era bricks from the flame trench 

and installed more than 96,000 heat-resistant bricks, in 

three different sizes, using bonding mortar and, where 

NASA’s mobile launcher, atop Crawler-Transporter 2, moves into High Bay 3 at the Vehicle Assembly Building (VAB) on Sept. 8, 2018, at Kennedy 

Space Center. Image credit: NASA

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required, steel plate anchors. In areas where significant 

temperature and pressure will occur, technicians fastened 

steel plate anchors to the walls at intervals to reinforce the 

brick system.

The deflector is made up of 150 steel plates, each weighing 

up to 4,000 pounds, and it measures 57 feet wide, 43 feet 

high, and 70 feet long. The deflector’s north side is slanted 

at about a 58-degree angle and will redirect the rocket’s 

exhaust, pressure, and intense heat to the north at liftoff.

The flame trench and deflector are above ground level, and 

the two main structures on either side of the flame trench 

serve as the platform to support the mobile launcher and 

rocket. These structures are the catacombs on the east 

side and the Pad Terminal and Communication Room 

(PTCR)/Environmental Control System (ECS) room on 

the west side of the flame trench, which is the area below 

the pad containing water lines and piping. As part of the 

refurbishment, teams also reinforced the roof of the catacomb to be able to support 25.5 million pounds.

Lightning Towers

Teams installed three 600-foot-tall masts with overhead 

wires used to transmit electrical energy around the perimeter of the pad to provide lightning protection for rockets 

as they are processed and launched from the pad.

Propellant Systems

Along the pad perimeter are storage spheres for liquid 

oxygen to the northwest of the pad and liquid hydrogen to 

the northeast of the pad. The liquid oxygen system holds 

in excess of 850 thousand gallons of liquid oxygen, which 

is transferred to the SLS rocket during launch countdown 

via lines from the sphere to the pad. The liquid hydrogen 

system holds in excess of 850 thousand gallons of liquid 

hydrogen, which is transferred to the SLS rocket during 

launch countdown via vacuum jacketed lines from the 

sphere to the pad. A second liquid hydrogen sphere is under 

construction to store in excess of 1.25 million gallons of 

liquid hydrogen for transfer to the rocket beginning with 

the second launch of SLS.

Mobile Launcher

Weighing over 11 million pounds and standing 400 feet 

tall, the mobile launcher is the ground structure that will 

be used to assemble, process, and launch the SLS rocket 

and Orion spacecraft from Launch Pad 39B for the first 

three Artemis missions.

The launcher is designed to support the assembly, testing, 

checkout, and servicing of the rocket, as well as to transfer 

it to the pad and serve as the structural platform from 

which it will launch. During preparations for launch, 

the crawler-transporter will pick up and move the mobile 

launcher into high bay 3 in the VAB. The launcher will 

be secured atop support posts, called mount mechanisms, 

and the crawler will move out of the way. 

The mobile launcher for the Block 1 configuration of the 

SLS rocket consists of a two-story base, which is 25 feet 

high, 165 feet long, and 135 feet wide. The base serves 

as the platform for the rocket and a tower that will be 

equipped with several connection lines, called umbilicals, 

and launch accessories that will provide SLS and Orion 

with power, communications, coolant, propellant, and 

stabilization prior to launch. The tower stands about 345 

feet tall and contains a walkway for personnel and equipment entering the crew module during launch preparations, as well as astronauts on crewed missions. There are 

tower floor levels every 20 feet for personnel to access the 

rocket and ground support equipment. 

The launcher will roll out to the pad for launch atop 

the crawler-transporter, carrying SLS and Orion. After 

the crawler-transporter makes the eight-hour trek to the 

pad just over four miles away, engineers will lower the 

launcher onto the pad and remove the crawler-transporter. 

During launch, each umbilical and launch accessory will 

release from its connection point, allowing the rocket and 

spacecraft to lift off safely from the launch pad.

Umbilicals

Aft Skirt Electrical Umbilicals: Two aft skirt electrical 

umbilicals connect to the SLS rocket at the bottom outer 

edge of each booster and provide electrical power and 

data connections to the SLS rocket until it lifts off from 

the launch pad. The umbilicals act like a telephone line 

and carry a signal to another subsystem on the mobile 

launcher called the launch release system. This system 

distributes the launch signal to the rest of the launch 

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accessories and the SLS boosters, and it initiates the 

launch release command.

Aft Skirt Purge Umbilicals: Two aft skirt purge umbilicals 

connect to the SLS rocket at the bottom outer edge of 

each booster to remove potentially hazardous gases and 

maintain the required temperature range of components 

through a heated gaseous nitrogen purge to the cavity of 

each booster’s aft skirt. Teams connect these umbilicals 

during stacking operations in the VAB, and they remain 

connected until released during liftoff.

Tail Service Mast Umbilicals: Two tail service mast umbilicals connect the zero-level deck on the mobile launcher 

to the SLS rocket core stage aft section. These umbilicals 

are about 33 feet tall and provide liquid oxygen and liquid 

hydrogen fluid lines and electrical cable connections to 

the SLS core stage engine section to support propellant 

handling during pre-launch operations. The umbilicals 

tilt back before launch to ensure that all hardware safely 

and reliably disconnects and retracts from the rocket 

during liftoff.

Core Stage Intertank Umbilical: The core stage intertank 

umbilical is a swing arm umbilical that connects to the 

SLS core stage intertank. The intertank umbilical’s main 

function is to vent gaseous hydrogen, which is boiloff from 

the extremely cold liquid hydrogen fuel, from the core 

stage. The arm also provides conditioned air, pressurized 

gases, and power and data connection to the core stage. 

This umbilical, located at the 140-foot level on the mobile 

launcher tower, swings away at launch.

Core Stage Forward Skirt Umbilical: The core stage forward 

skirt umbilical is located at the 180-foot level on the mobile 

launcher tower, above the liquid oxygen tank. This umbilical 

will swing into position to connect to the core stage forward 

skirt of the SLS rocket and then swing away before launch. 

Its main purpose is to provide conditioned air and nitrogen 

gas to the SLS Core Stage Forward Skirt cavity.

Interim Cryogenic Propulsion Stage Umbilical: The 

interim cryogenic propulsion stage umbilical is located at 

about the 240-foot level on the mobile launcher tower. 

This umbilical supplies fuel, oxidizer, purge air, gaseous 

nitrogen and helium, and electrical connections to the 

interim cryogenic propulsion stage of the SLS rocket. The 

umbilical also provides hazardous gas leak detection and 

swings away before launch.

Orion Service Module Umbilical: The Orion service module umbilical connects the mobile launcher tower to the 

Orion service module. The umbilical is located at the 280-

foot level of the tower and, prior to launch, will transfer 

liquid coolant and air for the electronics and purge air 

and nitrogen gas for the environmental control system to 

support the spacecraft and the LAS. The umbilical tilts 

back before launch. 

Launch Accessories Crew Access Arm: The crew 

access arm is located at the 274-foot level on the mobile 

Crew Access Arm

Umbilicals

Launch Accessories

Vehicle Stablizer System

Vehicle Support Posts

Orion Command 

and Service Modules

Interim Cryogenic 

Propulsion Stage

Core Stage Forward Skirt

Core Stage Inter-tank

Aft Skirt Electrical (2)/

Purge (2)

Tail Service Mast (2)

Diagram of the umbilicals and launch accessories for the SLS.

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launcher tower. The arm rotates from its retracted position and interface with the SLS rocket at the Orion crew 

hatch location to provide entry to and exit from the 

Orion crew module during operations in the VAB and 

at the launch pad. The access arm provides a clean and 

controlled work area for people and equipment entering 

the crew module, an egress path during an emergency, 

and access to servicing panels for the Orion crew module and service module. On crewed missions, the access 

arm also provides entry and exit for astronauts. The 

arm retracts from the Orion spacecraft before launch.

Vehicle Stabilizer System: The vehicle stabilizer system 

is located at the 200-foot level of the mobile launcher 

tower and provides a structural interface to the SLS 

core stage. The system helps reduce core stage motion 

during rollout to the launch pad, processing operations, 

high-wind events at the pad, and the launch countdown. 

The stabilizer drops down and away from the rocket 

at launch.

Vehicle Support Posts: Eight posts support the load of the 

solid rocket boosters, with four posts for each booster. The 

support posts, made of cast steel, are five feet tall and each 

weigh about 10,000 pounds. They are located on the deck 

of the mobile launcher and are instrumented with strain 

gauges to measure loads during stacking, integration, 

rollout, and launch operations. The posts will structurally 

support the SLS rocket through T-0 and liftoff.

Crawler-Transporter

NASA has upgraded one of a pair of behemoth machines, 

called crawler-transporters, to handle the combined SLS 

rocket and mobile launcher combination. NASA modified Crawler-Transporter 2, also known as CT-2, for 

Artemis from its previous use to move the space shuttle 

and Saturn V rocket with redesigned and upgraded roller 

bearings, a new assembly that can carry a greater load, 

and an improved lubrication system. The crawler’s uprated 

load-carrying capacity is 18 million pounds, 50% higher 

than the original design. The crawler does not interface 

with the rocket, enabling it to also carry other future 

rockets with no additional modifications needed.

Larger than the size of a baseball infield and powered by 

locomotive and large electrical power generator engines, 

the crawler weighs approximately 6.6 million pounds, and 

the overall size of the crawler is 131 feet long, 114 feet 

wide, and 20 to 26 feet tall, based on the position of the 

jacking equalization and leveling cylinders. The crawler 

was designed to travel 2 mph unloaded, and speed while 

carrying a rocket and spacecraft is limited by analysis that 

determines what rate provides the smoothest ride. As of 

the end of 2021, CT-2 has traveled 2,365 miles.

Able to raise and lower its sides and corners independently, 

the crawler is designed to roll underneath the mobile 

launcher while inside the VAB, pick it up, and steadily 

carry it 4.2 miles to Launch Pad 39B. The crawler has four 

reinforced pickup points on its surface that secure into 

place underneath the mobile launcher to carry it to the 

pad. Pinch blocks are located at three of the four pickup 

points to secure the load being carried. The crawler uses 

its hydraulic suspension to keep the platform level all the 

way to the top pad, which is built atop a sloping pyramid, 

where it sets the platform in place.

Once the crawler makes the eight-hour trek to the pad 

with engineers and technicians aboard, the mobile 

launcher and SLS will be lowered onto pad mount mechanisms. After platforms are lowered and power transfers 

are complete, the crawler rolls back down the pad slope 

and parks just outside the pad perimeter gate. The crawler 

will wait there until a few days prior to launch in case a 

rollback is required. Then it will roll to a parking site to be 

protected during launch.

Crawlerway

The crawlerway is the 4.2-mile path from the VAB to 

Launch Pad 39B that was constructed in 1964. From 

outside edge to outside edge, the crawlerway is 130 feet 

wide and is composed of two 40-foot lanes, with a 50-foot 

grass median strip in between them. The top layer is composed of a river walk 4 inches (10 centimeters) thick on 

the straight sections and 8 inches (20 centimeters) thick 

on curves. Underneath is at least four feet of crushed lime 

rock, which sits atop as much as 20 feet of hydraulically 

compressed fill. From the VAB to Pad B there is approximately 45,000 tons of rock.

For the Artemis I mission, the path from the VAB to 

Launch Complex 39B must be able to support at least 

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25.5 million pounds for the crawler as well as the massive 

weight of the SLS rocket, the Orion spacecraft, and the 

mobile launcher. Teams have performed crawlerway conditioning to ensure that the crawlerway is strong enough 

to withstand the weight and provide stability for the 

Artemis I mission, as well as even heavier loads in anticipation of heavier payloads on future missions.

Conditioning the crawlerway is essential to preventing a phenomenon called liquefaction, in which the 

crawler-transporter, the mobile launcher, and the load on it 

causes the crawlerway to vibrate and shake the soil to the 

point that the soil itself will behave like a liquid instead of 

a solid, causing the crawler to tip to one side or the other. 

To condition the crawlerway, technicians lifted dozens of 

concrete blocks, each weighing over 40,000 pounds, onto 

a mobile launcher platform previously used for the space 

shuttle and CT-2. Engineers then drove the loaded transporter up and down the path between the VAB and launch 

pad, with each pass increasingly compacting the soil.

Software

Spacecraft Command and Control System

The computer software and hardware that operate, monitor, and coordinate the ground equipment for the launch 

of the SLS rocket and Orion spacecraft are called the 

spacecraft command and control system (SCCS). The SLS 

rocket and Orion spacecraft generate about 100 megabytes 

 Teams at Kennedy work to strengthen the crawlerway for launch by driving Crawler-Transporter 2 (CT-2), carrying a mobile launcher platform that 

was used during the Space Shuttle Program, back and forth on the crawlerway on Jan. 22, 2021, with several cement blocks, each weighing about 

40,000 pounds. Image credit: NASA

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of data per second at liftoff, demanding a robust computer 

system that can process the volume and speed of this 

information needed to deliver to that data to the launch 

team and corresponding mission systems in real time. The 

system is the electronic hub where information traveling 

to and from the SLS core stage, the rocket’s ICPS, Orion, 

ground systems, and the operators inside the firing room 

intersect. During loading and launch, the software will 

process up to 575,000 changes per second.

The SCCS represents a suite of advanced software tailored 

to the unique needs of SLS and the Orion spacecraft. It is 

designed to take advantage of modern computers, servers, 

and information technology to provide a faster, safer, and 

more reliable network than systems previously developed 

to support the space shuttle. Engineers also designed it 

to be upgraded and adapted to support the rocket and 

spacecraft as they are flown in different configurations 

and advanced variants.

Recovery Operations

In addition to the hardware elements that are part of the 

ground systems supporting launch, the landing and recovery team, led by EGS from Kennedy, will be responsible 

for safely recovering the Orion capsule, as well as crew on 

future missions, after splashdown and returning them to 

land. The interagency landing and recovery team consists 

of personnel and assets from the U.S. Department of 

Defense, including Navy amphibious specialists and Air 

Force weather specialists, and engineers and technicians 

from Kennedy, Johnson, and Lockheed Martin.

Before splashdown of the spacecraft, the recovery team 

will head out to sea in a Navy amphibious ship that has a 

well deck at the waterline to allow boats to dock inside the 

back of the ship. At the command of the NASA recovery 

director, Navy divers and other team members in several 

inflatable boats will approach Orion. When Orion is 

ready to be pulled into the well deck, the divers will attach 

a cable, called the winch line, and up to four additional 

tending lines to attach points on the spacecraft to pull 

the spacecraft into the ship. The winch will pull Orion 

into a specially designed cradle inside the ship’s well deck, 

and the other lines will control the lateral motion of the 

spacecraft. Once Orion is positioned above the cradle 

assembly, the team will drain the well deck and secure 

Orion on the cradle.

During a crewed mission, astronauts can be recovered in 

either open water or the well deck of the ship, depending 

on sea conditions and other factors on the day of landing. 

For an open-water crew egress, the Navy divers will install 

a stabilization collar around the spacecraft as well as an 

inflatable platform, known as the front porch, to assist 

with stabilizing Orion and helping recover the astronauts. 

During crew recovery in the well deck, technicians will 

pre-position a crew egress stand to access and recover 

the crew after the spacecraft is fully recovered into the 

well deck.

Open-water personnel will work to recover Orion’s forward bay cover and three main parachutes to the port 

side of the Navy ship, where a crane will lift them onto 

the ship’s main deck. If teams recover the jettisoned cover 

and parachutes, engineers can inspect the hardware and 

gather additional performance data. Teams will transport 

the spacecraft and other hardware on the ship from the 

landing site to a pier at U.S. Naval Base San Diego. After 

NASA’s’ mobile launcher makes a solo trek along the crawlerway atop 

Crawler-Transporter 2 to Kennedy’s Launch Complex 39B on June 27, 2019.

Image credit: NASA

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Exploration Ground Systems > Testing

technicians secure Orion and the other associated hardware in the recovery transportation fixture, a platform 

nicknamed the Armadillo, they will transport the hardware by truck to Kennedy.

Testing

Integrated Test and Checkout 

Tests to Prepare for Flight

The integrated test and check out series performed after 

SLS was assembled in the VAB and at the launch pad thoroughly tested all the systems, end to end, prior to launch.

• Modal Tests: These tests characterize vibration 

“modes” for the integrated structure using hydraulic 

shakers and calibrated hammers.

• Interface Verification Test: Also performed with the 

Orion stage adapter test article and the Orion simulator, as well as with the Artemis I Orion, this test verifies functionality and interoperability of SLS-to-Orion 

interfaces.

• Communications End-to-End Test: This test validates 

communications between the integrated rocket and 

spacecraft and the ground using a radio frequency 

antenna in the VAB, another near the pad that covers 

the first few seconds of launch, and a more powerful 

antenna that uses the Tracking and Data Relay Satellite 

System and the Deep Space Network.

• Umbilical Release and Retract Test: This process tests 

the timing of booster arming and firing and the command for umbilical release.

• Vehicle Assembly Building Project-Specific 

Engineering Test: This test performs element-level 

testing of SLS in the VAB.

• Countdown Sequence Test: With a simulated launch 

countdown inside the VAB, this test demonstrates the 

ground launch software and ground launch sequencer, 

which checks for health and status of the rocket and 

spacecraft sitting on the pad. 

• Flight Safety System Test: This test serves as a rehearsal 

for pre- and post-wet dress and ordnance and flight 

termination system communications.

• Dynamic Rollout Test: This test rolls the integrated 

rocket and spacecraft from the VAB to Launch 

Inside High Bay 3 of the Vehicle Assembly Building at Kennedy Space 

Center, the work platforms are shown retracted from around the Artemis I 

Space Launch System on Sept. 20, 2021. All 10 levels of platforms were 

extended and retracted as part of an umbilical test. Image credit: NASA

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Complex 39B and back again to compare actual loads 

to analytical models.

• Pad Project-Specific Engineering Tests: These procedures at the launch pad test radio frequency, as well as 

guidance, navigation, and control; they also perform 

final ordnance tests.

• Wet Dress Rehearsal: This process tests propellant loading procedures, structural response, thermal conditioning and loading procedures, the vehicle control system, 

avionics and software checkout, electromagnetic interference, guidance and navigation, the main propulsion 

system, engine and booster nozzle steering, and more.

Crawler-Transporter

Engineers tested the new modifications on CT-2 incrementally to prepare for the first integrated flight test of 

SLS and Orion. The 20-year-life modifications roll-tested 

the new 1,500-kilowatt generators, parking and service 

brakes, control system modifications, diesel engine refurbishments, vent hoods, exhaust, and other upgrades.

Sound Suppression Testing

Water flow sound suppression tests at Launch Pad 38B 

are one of the final checkouts ahead of the launch of 

Artemis I. At launch, the SLS rocket will produce nearly 

nine million pounds of thrust—and a lot of sound. The 

purpose is to reduce and dampen damaging acoustic 

and thermal energy and high-pressure sound waves that 

could otherwise damage the mobile launcher, the launch 

pad infrastructure and flame trench, and even the rocket. 

During liftoff, the sound level reaches 176 decibels, and 

the water flow cuts vibrations and sound down by a few 

decibels, sufficient to minimize pad damage.

 A wet flow test at Launch Pad 39B on Sept. 13, 2019, tests the sound suppression system that will be used for the launch of NASA’s Space Launch 

System for the Artemis I mission. During the test, about 450,000 gallons of water poured onto the Pad B flame deflector, the mobile launcher flame hole, 

and the launcher’s blast deck. Image credit: NASA

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Underway Recovery Testing

Teams have practiced procedures and operations in 

Johnson’s Neutral Buoyancy Laboratory pool and in the 

open water off the coast of California during a series of 

underway recovery tests, using a test version of the Orion 

spacecraft and other equipment that will be used during 

recovery operations. The term “underway” refers to recovery tests done when a ship is at sea.

These tests help to evaluate and improve recovery procedures and hardware ahead of Orion’s flight on Artemis I 

and prior to the first crewed mission, Artemis II. Testing 

also included recovering the spacecraft from Orion’s first 

flight test, EFT-1, when Orion splashed down in the 

Pacific Ocean about 600 miles off the coast of San Diego, 

California, at the end of the test.

Launch Simulations

In preparation for Artemis I, teams in the Launch Control 

Center (LCC) have been performing launch simulations 

that involve rehearsing all aspects of the launch countdown. Under the leadership of the Artemis I Launch 

Director, Kennedy’s team of engineers are seated at 

consoles inside Firing Room 1 and Firing Room 2 of the 

LCC for the simulations, using software to replicate the 

commands and operations they will be giving and monitoring on launch day. Launch countdown simulations also 

include the participation of engineers and test directors 

from Johnson and Marshall.

Simulations include training exercises that introduce fictional but realistic problems for engineers to identify and 

work through. They take teams from cryogenic loading—

filling tanks in the SLS core stage with supercold liquid 

hydrogen and liquid oxygen—all the way through countdown and liftoff. These tests ensure that the Artemis I 

launch team is prepared for launch day.

Management Roles and Facilities

Kennedy Space Center

Kennedy is home to the Exploration Ground Systems 

Program and has transformed many facilities from 

their heritage shuttle or Saturn V and Apollo roles to 

support Artemis missions, focusing on the equipment, 

management, and operations required to safely process, 

assemble, transport, and launch the Orion spacecraft and 

SLS rocket.

Multi-Payload Processing Facility

A unique facility at Kennedy, the Multi-Payload Processing 

Facility (MPPF) is used to fuel the Orion spacecraft with 

hazardous propellants and other fluids the spacecraft will 

need for the journey around the Moon.

The spacecraft is moved out of the O&C aboard a transport pallet and air-bearing system that sits on top of a 

transporter. In the MPPF, it is moved into a service stand 

Navy divers practice recovering a mock Orion capsule during an 

Underway Recovery Test on Nov. 3, 2021. Image credit: NASA

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that provides 360-degree access, allowing engineers and 

technicians from EGS, Jacobs, and other support organizations to fuel and service the spacecraft. Crane operators 

remove the transportation cover and use fuel lines and 

several fluid ground support equipment panels to load the 

various gases and fluids into the crew and service modules.

When Orion returns to Earth after its mission, technicians 

will transport it to the MPPF, where they will use specialized equipment to remove unused hazardous propellants 

from its tanks during spacecraft post-flight processing.

Launch Abort System Facility

After fueling in the MPPF, teams move the Orion spacecraft to the Launch Abort System Facility. The 50-foot 

-tall LAS, including ogive panels, is prepared horizontally 

inside the facility and then positioned on top of Orion 

for launch and ascent into orbit. The facility is taller than 

many processing facilities at Kennedy to allow clearance 

for vertical assembly of the Orion spacecraft with the 

LAS. The facility has cranes and other equipment needed 

to integrate the system during launch processing.

Booster Fabrication Facility

The Booster Fabrication Facility (BFF) is a 45-acre site at 

Kennedy, located near the VAB and the mobile launcher 

site. Northrop Grumman, lead contractor for boosters, 

and NASA engineers use the facility to refurbish, manufacture, and assemble the aft skirt assembly and forward 

assembly for the twin solid rocket boosters on SLS.

The BFF consists of seven buildings and includes facilities 

for the SLS Program’s solid rocket booster processing and 

administrative offices. The buildings that most significantly contribute to booster hardware processing include 

the Manufacturing Building, Multi-Purpose Logistics 

Facility, and Aft Skirt Test Facility.

Rotation, Processing and Surge Facility

The Rotation, Processing and Surge Facility (RPSF) 

receives the booster segments for the SLS rocket and 

prepares them for integration with other hardware in the 

VAB prior to launch.

The facility is over 90 feet high, more than 190 feet long, 

and about 90 feet wide. The large open area, called the 

high bay, contains several work stands and platforms to 

provide access to hardware during processing. Two 200-

ton cranes, one located at the east end of the building 

and the other at the west end, are positioned to lift the 

booster segments from a horizontal position to a vertical 

position. A crane control room provides access for two 

crane operators.

Railroad tracks lead to and continue through the facility 

to allow for transport and delivery of the large segments. 

During processing activities for the SLS rocket, the 

five booster segments will arrive at the RPSF by rail. 

Technicians will inspect the segments and rotate them to 

a vertical position for stacking operations.

The RPSF also will receive the booster aft skirt from the 

BFF. During processing, the aft segment is attached to the 

aft skirt and aft exit cone that covers the nozzle to compose 

the lower part, called the aft assembly. Teams will transport 

the aft assembly, three center segments, and the forward 

segment to one of two smaller surge facilities that are part 

of the RPSF complex for storage until needed for stacking.

Launch Equipment Test Facility

The Launch Equipment Test Facility (LETF) is a versatile 

test and development area used to test a wide variety of largescale hardware and ground support equipment components. 

Upgraded from its shuttle heritage to support Artemis 

missions, the LETF provided a proving ground to safely 

assess machinery to support the launch of the SLS 

rocket. Equipment at the facility can recreate liftoff and 

operational conditions to test component performance 

and can supply cryogenics, hydraulics, electrical systems, 

environmental control systems, and other commodities. 

Engineers build prototypes and test designs at the LETF 

on machinery that duplicates sections of a launch pad and 

simulates pressures and forces of launch to test in flightlike conditions.

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LETF Components

• Vehicle Motion Simulator: The vehicle motion simulator emulates all the movements a rocket makes as 

it is rolled to the launch pad and, more importantly, 

through the first 30 milliseconds of flight. This process 

allows exact simulations of the force and conditions 

under which umbilicals and other launch equipment 

must work to become qualified for use.

• North and East Towers: There are two towers at the 

LETF built to mirror the launch towers used for 

rockets. The simulation towers, while shorter than the 

structures seen at launch pads, are outfitted with the 

same features so engineers can evaluate launch pad 

designs ahead of rolling out a rocket. The north tower 

is a 60-foot-tall structure, and the east tower stands 

40 feet tall. Umbilical and access arms can be attached 

to the towers and used with the vehicle motion simulator to perform qualification testing.

• Test Fixture: Engineers use the 600-ton test fixture 

for multipurpose proof loading and conducting 

experiments to ensure hardware and ground support 

components can meet engineering requirements. 

• Water Flow Test Loop: Teams verify fluid lines and 

components such as valves, pumps, and meters in a 

test apparatus that can run parts and lines through 

high-flow tests to confirm them for operation and 

other uses. 

• Cryogenic Systems: The LETF is equipped with a 

cryogenic system for safely handling and using supercold chemicals and propellants commonly used in 

rocketry. Liquid nitrogen and liquid hydrogen can be 

pumped to areas of the LETF to accurately simulate 

launch operations with the vehicle motion simulator, 

towers, and other areas of the facility.

• Control Room, Workshops, and High Bay: The 

LETF is equipped with a full control room and the 

infrastructure to provide video and high-speed data to 

controllers, along with feeds for detecting hazardous 

gas leaks and other systems necessary to safely operate 

launch support equipment. 

Additionally, the LETF includes shops to make and 

assemble cables and pneumatic, hydraulic, and gas pressure systems for use throughout Kennedy facilities. There 

are machine and welding shops and an electrical shop. 

The LETF high bay is an indoor structure large enough to 

host the assembly of the large ground support structures. 

It is equipped with environmental control systems and an 

overhead crane.

Launch Control Center

The Rocco A. Petrone Launch Control Center (LCC) 

contains several control rooms, known as firing rooms, 

from which countdown and launch operations are supervised and commanded. Once the rocket has cleared the 

launch tower, control switches from the LCC over to 

Johnson’s MCC. Many activities involved with preparing 

rockets, spacecraft, and payloads for space can be controlled by engineers sitting at computer terminals in the 

firing rooms. Likewise, all activities at the launch pads 

can be run from a firing room. The LCC is also equipped 

with a suite of complex software linking the launch team 

operators inside the main firing room to the SLS rocket 

and Orion spacecraft in processing areas such as the VAB 

and the mobile launcher, as well as at Launch Complex 

39B, and to controllers at the Space Force Eastern Range 

and personnel at other NASA control centers. 

• Young-Crippen Firing Room: Today’s modernized 

firing rooms serve as the brain behind launch operations. EGS modified the Young-Crippen Firing Room, 

also known as Firing Room 1, for Artemis with the 

advanced computer and software systems that will 

allow greater situational awareness for launch controllers. Firing Room 1 will serve as the main firing room 

for Artemis I.

• Firing Rooms 2 and 3: Firing Rooms 2 and 3 will also 

support Artemis. EGS upgraded Firing Room 2 to 

support software verification and validation testing, 

provide simulation support, and serve as the location 

for support launch team personnel for Artemis missions on launch day. Teams have repurposed Firing 

Room 3 for use as a software design and development 

environment focused on software required to operate 

and control ground and flight hardware.

Industry Partners

Jacobs

Jacobs provides comprehensive services to NASA’s Artemis 

missions as a contractor to EGS, the Orion program, 

and the Space Launch System. Jacobs is the lead ground 

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Exploration Ground Systems > Quick Facts

and launch operations contractor for EGS at Kennedy, 

conducting all Artemis I flight hardware acceptance, 

processing, stacking, integration, testing, and launch 

support. The team helped develop the Artemis I launch 

control software and supports NASA in the LCC firing 

rooms for all countdown activities. At Marshall, Jacobs 

provided core stage systems engineering and integration 

support, and at Johnson, the team supported Orion parachute system development and fabrication.

Quick Facts

Mobile Launcher 1 (ML1)

Total height above ground ~400 ft (~122 m)

Two-story base 25 ft (7.7 m) high × 165 ft (50.3 m) 

long × 135 ft (41.1 m) wide

Height off ground 22 ft (6.7 m), “0” deck is 47 ft 

(14.3 m) off the ground

Height of six steel mount 

mechanisms

22 ft (6.7 m) (in VAB or on launch 

pad)

Height above the ground of 

mobile launcher deck when 

positioned on six steel mounts

47 ft (14.3 m) (in VAB or on launch 

pad)

The booster aft skirt sits on 

Vehicle Support Posts (VSPs)

Eight to support the rocket 

(four per booster) on the mobile 

launcher platform during transfer 

to the pad and at liftoff

Tower 40 ft (12.2 m) square, about 345 ft 

(105.2 m) tall

Tower floor levels Every 20 ft (6.1 m) for personnel 

access to the rocket and ground 

support equipment

Approximate ML1 weight ~11.3 million lb (~5,125.6 t)

Crawler-Transporter

Height Ranges from approximately 20 ft (6.1 m) to 26 ft (1.8 m), 

based on the position of the jacking, equalization, and 

leveling cylinders

Size Overall: 131 ft (40 m) long × 114 ft (35 m) wide. The 

mobile launcher contacts the crawler at four points, 

arranged in a 90-ft (27.4-m) square (same as the base 

line on a professional baseball field)

Weight Approximately 6.65 million lb (or the weight of about 15 

Statues of Liberty or 1,000 pickup trucks)

Speed Loaded: 1 mph

Unloaded: 2 mph

Load 

capacity

Able to transport 18 million lb (3,016.4 t) (or the weight of 

more than 20 fully loaded 777 airplanes)

Tower 40 ft (12.2 m) square, about 345 ft (105 m) tall

Hydraulic 

system

Reservoir capacity: 2,500 gal (11,365 L)

Steering: 4 pumps, 34.4 gallons (156.4 L) per minute 

(gpm)(lpm) @ 1,200 revolutions per minute (rpm) per 

pump

Steering pressure: 5,000 psi (34,474 kPa) maximum 

JEL: 8 pumps, 60 gpm (227 lpm) max, 15–20 gpm 

(56.8–75.7 lpm) nominal @ 1,200 rpm per pump

JEL pressure: 3,000 psi (20,670 kPa) maximum

Electrical Systems

DC power 

system

16 locomotive traction motors: 375 hp (280 kW) 

Diesel engines: Alco, 16 cylinders (2 @ 2,750 hp 

[2,051.5 kW] each, for DC) 

Generators (DC): 4 @ 1,000 kW each 

AC power 

system

Runs all onboard systems 

Diesel engines: Power, 16 cylinders, 2 @ 2,220 hp each, 

for AC power 

Generators (AC): 2 @ 1,500 kW each 

Capacity Diesel fuel capacity: 5,000 gallons (18,927.1 L)

Fuel consumption: 1 gal per 32 ft (10 m) (approximately 

165 gal (750 L) per mi); Drive system gear ratio: 168:1

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Exploration Ground Systems > Quick Facts

Vehicle Assembly Building 

• One of the largest buildings in the world by area, the VAB covers 

eight acres and is 525 feet (160 meters) tall and 518 feet (158 

meters) wide.

• At 130,130,415 cubic feet (3,684,883 cubic meters), it is one of the 

largest buildings in the world by volume.

• It is made up of 65,000 cubic yards (49,696 cubic meters) of 

concrete, and its frame is constructed from 98,590 tons of steel. 

It stands atop a support base of 4,225 steel pilings driven 164 feet 

(50 meters) into bedrock.

• The VAB high bay doors are the largest in the world at 456 feet 

(139 meters) high and take about 45 minutes to completely open 

or close.

• The building is home to a NASA logo that covers 12,300 square feet 

(1,142.7 square meters) and the largest American flag, at 209 feet 

(64 meters) tall by 110 feet (33.5 meters) wide, painted on the side 

of the VAB.

• The flag originally was painted onto the VAB in 1976 for the 

Bicentennial Exposition on Space and Technology.

• In 2020, repainting the American flag and the NASA logo required 

more than 500 gallons (1,893 liters) of paint.

• There is no platform I in the VAB so that it is not confused with the 

numeral 1.

• The building is listed in the National Register of Historic Places and 

is designated as a National Historic Civil Engineering Landmark.

Launch Pad 39B 

• During refurbishment projects, 1.3 million feet (396,240 meters) 

of copper cables were removed and replaced with 300,000 feet 

(91,440 meters) of fiber cable.

• The water tower for the Ignition Overpressure and Sound 

Suppression System holds roughly 400,000 gallons (1,818,436 

liters) of water, or enough to fill 27 average pools. This water is 

dumped on the mobile launcher and inside the flame trench in 

less than 30 seconds. The peak flow rate is 1.1 million gallons per 

minute (4,163,953 liters per minute), high enough to empty roughly 

two Olympic-size swimming pools in one minute.

• The three lightning towers are about 600 feet (183 meters) tall—

taller than the VAB, which is 525 feet (160 meters) tall.

• The catacomb roof was reinforced to be able to support 25.5 

million pounds (11,340 tons)—the equivalent of 2,125 average-size 

African elephants.

• The refurbished flame trench and new flame deflector will withstand temperatures of between 3,000 degrees and 5,600 degrees 

Fahrenheit (1,649 and 3,093 degrees Celsius) during launch.

• More than 96,000 bricks were installed on the walls of the flame 

trench during the refurbishment project.

• The flame trench is 450 feet (137 meters) long; that is equal to the 

length of about 1.5 football fields.

• The flame deflector is made up of about 150 steel plates, each 

weighing up to 4,000 pounds (1,814 kilograms).

• Liquid oxygen and liquid hydrogen tanks store supercooled liquid 

gases (that are used for propellant) at minus 297 degrees and 

minus 423 degrees Fahrenheit (147 and minus 423 degrees 

Celsius), respectively.

• Apollo 10 was the first mission to begin at Launch Pad 39B when it 

lifted off on May 18, 1969, to rehearse the first Moon landing.

• Three crews of astronauts launched to the Skylab space station in 

1973 from Pad 39B.

• Three Apollo astronauts who flew on the historic Apollo-Soyuz Test 

Project mission to link up in space also launched from Pad 39B.

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Space Communication 

and Navigation

Systems

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ARTEMIS REFERENCE GUIDE

Space Communication and Navigation Systems > Introduction

Artemis missions will rely on NASA’s comprehensive communications network services for journeys to lunar orbit. 

NASA’s worldwide network infrastructure will provide 

seamless communications, with different service levels as 

Orion leaves Earth, orbits the Moon, and returns safely 

home.

NASA’s Near Space Network and NASA’s Deep Space 

Network will support communication and navigation 

services. Communication services allow flight controllers 

to send commands to the spacecraft and receive data from 

Orion, the Space Launch System, and the rocket’s upper 

stage. Navigation, or tracking, services enable the flight 

controllers to calculate where the spacecraft are along their 

trajectory through space.

NASA’s Near Space Network

NASA’s Near Space Network provides a suite of communications and navigation services through commercial and 

government-owned, contractor-operated network infrastructure. The network will provide communications and 

navigation services during launch and navigation services 

at various points on the journey to the Moon.

Near Space Network Direct-To-Earth Services

The Near Space Network’s Launch Communications 

Segment (LCS) includes three ground stations along 

Florida’s coast to meet the specific needs of the SLS rocket 

and will provide links to both Orion and SLS during 

prelaunch and launch for Artemis I. Specifically, the first 

two stations along the rocket’s flight path will provide 

uplink and downlink communications between the rocket 

and mission controllers. In the final phases of ascent, the 

third station will downlink high-rate telemetry and video 

from SLS while Orion connects to communications relay 

satellites. The Near Space Network’s navigation services 

extend to Orion’s journey from low-Earth orbit to the 

Moon and back through ground stations in Santiago, 

Chile, and Hartebeesthoek, South Africa.

Near Space Network Relay Services

The Near Space Network also provides services to Artemis 

I through NASA’s Tracking and Data Relay Satellite 

(TDRS) constellation, which can provide near-continuous 

communications services. Located about 22,000 miles 

above Earth, TDRS relay data from spacecraft at lower 

altitudes to ground antennas during launch and low-Earth 

orbit phases of the Artemis I mission. TDRS will continue 

service until Orion and ICPS leave its coverage volume, 

when NASA’s Deep Space Network takes over, and then 

again on Orion’s return to Earth, from the final return 

trajectory correction burn through splashdown.

NASA’s Deep Space Network

The Deep Space Network (DSN) will handle communications beyond low-Earth orbit. Additionally, the network 

will facilitate communications during the deployment of 

CubeSats that will fly as secondary payloads on Artemis I 

with their own science and technology missions. The 

DSN consists of three facilities spaced equidistantly from 

each other—approximately 120 degrees apart in longitude—around the world. These sites are at Goldstone, 

near Barstow, California; near Madrid, Spain; and near 

Canberra, Australia. The strategic placement of these sites 

permits constant communication with spacecraft as Earth 

rotates—before a distant spacecraft sinks below the horizon at one DSN site, another site can pick up the signal 

and carry on communicating.

The Near Space Network and Deep Space Network 

will work together to support navigation for Orion so 

that engineers can employ a technique called three-way 

Doppler tracking. Using this method—with two ground 

stations on Earth in contact with Orion simultaneously, 

one from each network—NASA can triangulate Orion’s 

location relative to the ground stations.

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Space Communication and Navigation Systems > Acronym List

Acronym List

BFF Booster Fabrication Facility

CMUS crew module uprighting system

CT-2 Crawler-Transporter 2

DFI developmental flight instrumentation

DSN Deep Space Network

EFT-1 Exploration Flight Test-1

EGS Exploration Ground Systems

ESA European Space Agency

ESDMD Exploration Systems Development Mission Directorate

ESM European Service Module

FAST Final Assembly and System Testing

FCM flight computer module

GNC&P Guidance, Navigation, Control, and Propulsion

gpm gallons per minute

ICPS interim cryogenic propulsion stage

ITL Integrated Test lab

JEL Jacking, Equalizing, Leveling

kph kilometers per hour

LAS launch abort system

LCC Launch Control Center

LETF Launch Equipment Test Facility

LVSA launch vehicle stage adapter

MCC Mission Control Center

ML1 Mobile Launcher 1

ML2 Mobile Launcher 2

MPPF Multi-Payload Processing Facility 

O&C Neil Armstrong Operations and Checkout Building

OMS Orbital Maneuvering System

PBAN polybutadiene acrylonitrile

PDU power and data unit

PQM propulsion qualification module

PSI pounds per square inch

PTCR Pad Terminal and Communication Room

rpm revolutions per minute

RPSF Rotation, Processing and Surge Facility

SCCS Spacecraft Command and Control System

SLS Space Launch System

TDRS Tracking and Data Relay Satellite

TLI trans-lunar injection

TUFI toughened uni-piece fibrous insulation

ULA United Launch Alliance

VAB Vehicle Assembly Building

VSP Vehicle Support Post

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Space Communication and Navigation Systems

A Goldstone 111.5-foot (34-meter) Beam Waveguide antenna tracks a spacecraft as it comes into view. The Goldstone Deep Space Communications 

Complex is located in the Mojave Desert in California. Image credit: NASA

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Washington, DC 20546

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