SLS Assembly Bay
Rocket Assembly Builder
Build the Artemis Space Launch System
Assemble NASA's most powerful rocket, component by component. Learn each part, study the specs, pass the quiz, and watch your SLS come together.
Assembly Progress: 0 / 6 stages
01
Mobile Launcher & Launch Pad
The foundation that holds it all
📚 LEARN
The Mobile Launcher (ML) is a massive 380-foot-tall tower mounted on a two-story base platform. It holds the fully assembled SLS rocket upright and provides critical umbilical connections for fuel, electrical power, and data. The launch pad includes a flame trench that redirects the 6 million pounds of exhaust during liftoff, along with a water sound-suppression system that releases 450,000 gallons of water in just one minute to absorb acoustic energy.
The ML weighs about 10.6 million pounds empty and is transported to the pad on NASA's Crawler-Transporter 2 at a top speed of just 1 mph.
💼 CAREERS AT THIS STAGE
Construction Worker
Electrician
Structural Engineer
⚡ FLASHCARDS
How tall is the Mobile Launcher?
380 feet tall, weighing 10.6 million pounds
What do umbilical connections provide?
Fuel, electrical power, and data to the rocket before liftoff
What is the flame trench for?
Redirects 6 million pounds of exhaust away from the rocket during liftoff
🎯 QUIZ GATE
Q1. How tall is NASA's Mobile Launcher tower?
Q2. What does the flame trench do during launch?
Q3. What do umbilical connections supply to the rocket?
02
Solid Rocket Boosters
75% of liftoff thrust
📚 LEARN
Two Solid Rocket Boosters (SRBs) flank the core stage, each standing 177 feet tall. Together they provide roughly 75% of total thrust at liftoff — about 7.2 million pounds combined. Each booster uses a 5-segment design (an upgrade from the Shuttle's 4-segment boosters). They burn solid propellant for approximately 2 minutes before separating and falling into the ocean.
The propellant inside each SRB is a mix of aluminum powder (fuel), ammonium perchlorate (oxidizer), and a rubber-like binder — essentially a controlled, powerful chemical reaction.
💼 CAREERS AT THIS STAGE
Chemical Engineer
Machinist
Quality Inspector
⚡ FLASHCARDS
How many segments does each SRB have?
5 segments, an upgrade from the Shuttle's 4-segment design
How much thrust do the SRBs provide at liftoff?
About 75% of total liftoff thrust (7.2 million lbs combined)
How long do the SRBs burn?
Approximately 2 minutes before they separate and fall into the ocean
🎯 QUIZ GATE
Q1. What percentage of liftoff thrust do the SRBs provide?
Q2. How many segments make up each SLS solid rocket booster?
Q3. What happens to the SRBs after they burn out?
03
Core Stage (The Backbone)
212-foot orange powerhouse
📚 LEARN
The Core Stage is the backbone of the SLS — a towering 212-foot-tall orange cylinder that holds liquid hydrogen (fuel) and liquid oxygen (oxidizer) in two massive tanks. At its base, four RS-25 engines (upgraded versions of the Space Shuttle Main Engines) produce a combined 2 million pounds of thrust. The core stage fires for about 8 minutes before separating.
The RS-25 engines are among the most tested rocket engines ever built. They operate at temperatures ranging from -423 degrees F (liquid hydrogen) to over 6,000 degrees F in the combustion chamber.
💼 CAREERS AT THIS STAGE
Propulsion Engineer
Welder
Cryogenics Technician
⚡ FLASHCARDS
How tall is the SLS Core Stage?
212 feet tall — the largest single rocket stage NASA has ever built
How many RS-25 engines power the core?
4 RS-25 engines producing 2 million pounds of combined thrust
What fuels does the core stage use?
Liquid hydrogen (fuel) and liquid oxygen (oxidizer), stored at cryogenic temperatures
Where did the RS-25 engines come from?
They are upgraded Space Shuttle Main Engines, among the most tested rocket engines ever
🎯 QUIZ GATE
Q1. How many RS-25 engines does the core stage have?
Q2. What two cryogenic liquids fuel the core stage?
Q3. How tall is the SLS core stage?
04
Interim Cryogenic Propulsion Stage
The final push beyond Earth
📚 LEARN
The Interim Cryogenic Propulsion Stage (ICPS) is the upper stage that sits on top of the core. After the core stage separates, the ICPS fires its single RL10 engine to provide the final push. Its most critical job is the Trans-Lunar Injection (TLI) burn — the precise engine firing that sends Orion out of Earth orbit and toward the Moon (or eventually Mars). The ICPS is based on the proven Delta IV upper stage.
The TLI burn lasts about 18 minutes and accelerates the spacecraft to roughly 24,500 mph — fast enough to escape Earth's gravitational pull.
💼 CAREERS AT THIS STAGE
Aerospace Engineer
Software Developer
Test Engineer
⚡ FLASHCARDS
What engine powers the ICPS?
A single RL10 engine, based on proven Delta IV technology
What is Trans-Lunar Injection (TLI)?
The engine burn that pushes the spacecraft out of Earth orbit toward the Moon or Mars
When does the ICPS fire?
After the core stage separates — it provides the final push to leave Earth orbit
🎯 QUIZ GATE
Q1. What engine does the ICPS use?
Q2. What does "Trans-Lunar Injection" mean?
Q3. When does the ICPS fire its engine?
05
Orion Spacecraft + Service Module
Crew capsule for 4 astronauts
📚 LEARN
Orion is the crew capsule that carries up to 4 astronauts. Below it sits the European Service Module (ESM), built by the European Space Agency, which provides propulsion, electrical power via solar panels, air, and water. Orion's heat shield is the largest ever built — rated for temperatures exceeding 5,000 degrees Fahrenheit during reentry at speeds up to 25,000 mph. The heat shield uses an ablative material called AVCOAT that chars and flakes away, carrying heat with it.
Orion is designed for deep space missions — unlike the ISS-bound spacecraft, it can keep astronauts alive for up to 21 days in space without docking.
💼 CAREERS AT THIS STAGE
Flight Surgeon
Materials Scientist
Electrical Engineer
⚡ FLASHCARDS
How many astronauts can Orion carry?
Up to 4 astronauts for deep space missions lasting up to 21 days
What does the European Service Module provide?
Propulsion, electrical power (solar panels), breathable air, and water
How hot does Orion's heat shield get?
Over 5,000 degrees F during reentry at speeds up to 25,000 mph
What material is the heat shield made of?
AVCOAT — an ablative material that chars away, carrying heat with it
🎯 QUIZ GATE
Q1. How many astronauts can Orion carry?
Q2. Who built the European Service Module?
Q3. What temperature can Orion's heat shield withstand?
06
Launch Abort System + Fairings
Emergency escape and protection
📚 LEARN
The Launch Abort System (LAS) is the emergency escape rocket mounted on top of Orion. If something goes wrong during launch, the LAS can fire in milliseconds, pulling the crew capsule away from a failing rocket at extreme speed. It has three motors: the abort motor (400,000 lbs of thrust), the attitude control motor (for steering), and the jettison motor (to discard the LAS after it's no longer needed). The fairings are protective panels around Orion that shield it from aerodynamic forces during ascent. Both the LAS and fairings are jettisoned after clearing the atmosphere.
The abort motor is the fastest-reacting escape system ever built for a crewed spacecraft. From zero to full thrust in milliseconds, generating a force of about 15 Gs — strong enough to pull the crew free in any emergency.
💼 CAREERS AT THIS STAGE
Safety Engineer
Systems Integration Specialist
Pyrotechnics Technician
⚡ FLASHCARDS
How fast can the LAS activate?
In milliseconds — it's the fastest escape system ever built for a crew vehicle
What are the three LAS motors?
Abort motor (400,000 lbs thrust), attitude control motor (steering), and jettison motor (discard)
What do the fairings protect against?
Aerodynamic forces during ascent through the atmosphere
When are the LAS and fairings jettisoned?
After the rocket clears the atmosphere — they are no longer needed in the vacuum of space
🎯 QUIZ GATE
Q1. How quickly can the Launch Abort System activate?
Q2. What do the fairings protect Orion from?
Q3. How much thrust does the LAS abort motor produce?