Space Launch System

Overview

Key Features

Greatest Payload Mass: SLS’s 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. For trips to Earth’s Moon, SLS’s first configuration is able to lift more than 27 metric tons (59,500 lbs) to the lunar vicinity. By its fourth configuration, the lift capability of SLS to the Moon will grow to 46 metric tons (about 101,400 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 greater 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.

Four RS-25 engines are mounted to the bottom of the SLS rocket. In just 4 seconds, they reach over 2 million pounds of thrust and fire non-stop for 500 seconds to ensure SLS reaches space.

To do this, the RS-25 uses a staged-combustion engine cycle that combines liquid hydrogen and liquid oxygen propellants at a very high pressure to produce thrust. 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 Engines: L3Harris' RL10 engine powers the upper stage of the SLS, providing the main propulsion once the rocket has reached space. One RL10 engine was used on SLS when it made its inaugural flight on the Artemis I mission. On the second flight (Artemis II), 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. To date, more than 500 RL10 engines have launched hundreds of satellites to orbit and have sent spacecraft to every planet in our solar system.

Media Gallery

Rocket Science in 60 Seconds: How Structured Light Scanning Is Used on the SLS Rocket

Rocket Science in 60 Seconds: Building an Engine that Roars

RS-25 engine inspection inside the engine assembly room at Aerojet Rocketdyne's Stennis Space Center Facility (August 2015). 1 of 3

RS-25 engines, 2054 and 2057, are slated for Artemis III, the third flight of NASA’s Space Launch System. They are pictured at Aerojet Rocketdyne’s facility located at NASA’s Stennis Space Center.

RS-25 engine, 2057, is slated for the Artemis III, the third flight of NASA’s Space Launch System. The photo was taken at Aerojet Rocketdyne’s facility located at NASA’s Stennis Space Center.

An Aerojet Rocketdyne engineer examines RS-25 engine

Aerojet Rocketdyne RS-25 engine 2048 is an Artemis III engines, which means is it slated for the third flight of NASA’s Space Launch System.

- The core stage for the first flight of NASA’s SLS rocket

Artist rendition of NASA's Block 1 Space Launch System

NASA artistic rendetion of the Space Launch System's

Aerojet Rocketdyne’s RL10 engine powers the upper stage of NASA's SLS rocket

Aug. 13, 2015 - RS-25 engine test close up from inside A-1 test stand at NASA's Stennis Space Center.

August 2015 - RS-25 engine inspection inside the engine assembly room at our Stennis Space Center Facility.

August 2015 - RS-25 development engine 0525 in the A-1 test stand at NASA's Stennis Space Center in Mississippi undergoes inspection by technicians.

An RS-25 engine for NASA's Space Launch System prepares for hot-fire testing at NASA's Stennis Space Center in Mississippi.

Oct. 11, 2017 - Aerojet Rocketdyne, prior to being acquired by L3Harris, displays the four RS-25 engines slated to fly on EM-1, the maiden flight of NASA's SLS rocket, at its facility located at NASA's Stennis Space Center.

June 28, 2019 - Aerojet Rocketdyne, prior to being acquired by L3Harris, delivered four RS-25 engines for integration with NASA’s Space Launch System core stage from its facility at NASA’s Stennis Space Center to NASA’s Michoud Assembly Facility.

RS-25 engines, 2054 and 2057, are slated for Artemis III, the third flight of NASA’s Space Launch System. They are pictured at our facility located at NASA’s Stennis Space Center.

RS-25 engines, 2054 and 2057, are slated for Artemis III, the third flight of NASA’s Space Launch System (SLS). Four RS-25 engines power each SLS launch.

RS-25 engine, 2057, is slated for the Artemis III, the third flight of NASA’s Space Launch System. The photo was taken at our facility located at NASA’s Stennis Space Center.

An engineer at its facility located at NASA’s Stennis Space Center examines RS-25 engine, 2057, which is slated for the Artemis III, the third flight of NASA’s Space Launch System.

Our RS-25 engine 2048 is an Artemis III engine, which means is it slated for the third flight of NASA’s Space Launch System.

Assembled and flight certified after the completion of the Space Shuttle program, RS-25 engine 2063 is slated to launch on Artemis II, the second flight of NASA’s Space Launch System (SLS). Four RS-25 engines power each SLS launch.

The core stage for the first flight of NASA’s SLS rocket is seen in the B-2 Test Stand during a scheduled eight-minute duration hot fire test Jan. 16, 2021, at NASA’s Stennis Space Center near Bay St. Louis, Mississippi. (Credit: NASA)

NASA conducts a hot fire test Jan. 16, 2021, of the core stage for the agency’s Space Launch System rocket on the B-2 Test Stand at Stennis Space Center near Bay St. Louis. (Credit: NASA)

Artist rendition of NASA's Block 1 Space Launch System from inside the Vehicle Assemble Building (VAB) at NASA's Kennedy Space Center. (Image courtesy of NASA)

Artist rendition of NASA's Block 1 Space Launch System rolling out to the Pad. (Image courtesy of NASA)

Artist rendition of NASA's Block 1 Space Launch System on the launch pad. (Image courtesy of NASA)

Artist rendition of NASA's Block 1 Space Launch System on the launch pad at sunset. (Image courtesy of NASA)

Artistic rendition of the Space Launch System's Exploration Upper Stage powered by four RL10 engines built by L3Harris. (Credit: NASA)

Nov. 6, 2019 - Four RS-25 engines attached to the core stage for NASA’s Space Launch System rocket for NASA’s Artemis I mission to the Moon. (Credit: NASA)