Space Launch System

Powering NASA’s Space Launch System

NASA’s Space Launch System (SLS), America’s next-generation heavy-lift rocket, is powered by Aerojet Rocketdyne. Our propulsion plays a critical role in SLS’s ability to successfully launch the heaviest, largest, and most valuable payloads to deep space.

OrionLaunch Abort System Crew Module & Service Module Interim Cryogenic Propulsion Stage Core Stage

Key Features

Greatest Payload Mass: Increased payload capability results in fewer launches and less complex operations to place infrastructure in deep space. Fewer launches also means decreased risk and cost associated with these complex missions. SLS will initially lift 70 metric tons (154,000 lbs), and eventually 130 metric tons (287,000 lbs) to low-Earth orbit. For trips to Earth’s Moon, SLS’s first configuration will be able to lift more than 26 metric tons (57,000 lbs) to the lunar vicinity. By its fourth configuration, the lift capability of SLS to the Moon will grow to 45 metric tons (about 99,000 lbs).

Largest Payload Volume: The capacity to launch the largest payload volume equates to the lowest mission complexity, risk and cost. It also allows for the greatest flexibility in the size and number of payloads that can be launched at once. More instruments and larger apertures can be accommodated by SLS, resulting in a greater amount of returns from the nation’s highest-priority science missions. At 8.4 meters, a future configuration of SLS (Block 1B) will have the largest fairing in the world.

Unmatched Speed: Faster speeds mean shorter duration trips and less exposure to harsh space environments for crew and cargo. It also means great scientific discoveries will return more quickly to Earth, and that costs will be reduced as a result of these accelerated timelines. SLS will carry crew and cargo to deep space faster and more efficiently than any other launch vehicle – enabling earlier arrival at destinations than by other means of in-space transportation.

Our Role

RS-25 Engines

The RS-25 is derived from the Space Shuttle Main Engine (SSME), which flawlessly powered 135 flights of the space shuttle. Between the shuttle and SLS programs, the RS-25 and SSME engines have experienced more than 1.1 million seconds of testing – making it the safest and most reliable liquid-booster engine in the world.

Aerojet Rocketdyne is the prime contractor for the high-performance RS-25 engine that will be used to propel SLS. For each flight, four RS-25 engines are mounted to the bottom of the rocket. In just 4 seconds, they’ll reach over 2 million lbs of thrust and fire non-stop for more than 8.5 minutes to ensure SLS reaches outer space.

To do this, the RS-25 uses a staged-combustion engine cycle that burns liquid hydrogen and liquid oxygen propellants at very high pressure. These engines operate in temperature extremes from minus 423 degrees Fahrenheit to 6,000 degrees Fahrenheit and at pressures exceeding 7,000 pounds per square inch. To fly SLS, the required power level for the RS-25 engines is 512,000 pounds vacuum thrust (109 percent of rated power level). Future evolutions will have even higher thrust capabilities.

RL10 Engine

Aerojet Rocketdyne’s RL10 engine will power the upper stage of the SLS, providing the main propulsion once the rocket has reached outer space. One RL10 engine will be used on SLS when it makes its inaugural flight, Exploratory Mission 1 (EM-1). On the second flight (EM-2), the RL10 will provide the power to send the Orion spacecraft and astronauts on the first mission to the Moon with humans since 1972. As the SLS rocket evolves to even more powerful configurations, it will incorporate four RL10 engines on the Exploration Upper Stage.

For over 50 years, the RL10 engine has been the nation’s premier upper-stage rocket engine. RL10 propelled the very first man-made object, Voyager I, into interstellar space. Since then, more than 480 RL10 engines have launched hundreds of satellites to orbit and have sent spacecraft to every planet in our solar system.