RL10 Engine
RL10 Propulsion System
Nearly six decades of reliably powering space exploration and national security
For nearly 60 years, Aerojet Rocketdyne’s RL10 engine has played a vital role in placing hundreds of military, government and commercial spacecraft into Earth’s orbit and beyond. The engine has helped send spacecraft to explore every planet in our solar system, including Voyager 1 and Voyager 2, the first spacecraft to reach interstellar space.
Today, multiple variants carry the RL10’s legacy forward as the launch industry’s “workhorse,” powering the upper stages of United Launch Alliance’s (ULA) Atlas V and Delta IV Heavy rockets. Two RL10 engines power the upper stage of ULA’s new Vulcan Centaur rocket.
RL10 engines also help power NASA’s Space Launch System (SLS) rocket, designed to carry astronauts to deep-space destinations aboard the Orion exploration spacecraft. A single RL10 powered the Interim Cryogenic Propulsion Stage on Artemis I, an un-crewed test flight of SLS and Orion. Four RL10 engines will support the more powerful Exploration Upper Stage that is being developed for future versions of SLS.
Aerojet Rocketdyne has developed and is working to qualify a modern version of the engine known as the RL10C-X that includes major components built using 3-D printing technology. Incorporating 3D printing into the manufacturing process will reduce lead times and cost while maintaining the outstanding performance and reliability customers have come to expect.
Key Features
Program Milestones
- 1959 First RL10 test
- 1963 First successful Atlas Centaur flight (two RL10 engines powered upper stage)
- 1964 Saturn S-4 Launch (six RL10 engines powered upper stage)
- 1993 First DC-X "Delta Clipper" flight (four RL10A-5 engines powered vehicle)
- 2002 First Atlas V flight (two RL10A-4-2 engines powered Centaur upper stage)
- 2009 400th RL10 engine flight
- 2010 Demonstrated deep-throttling from 104 percent of rated power down to 5.9 percent (an unprecedented thrust range of 17.6:1)
- 2013 RL10 marks 50 years of service
- 2014 First flight of RL10C-1
- 2020 500th RL10 engine flight
- 2021 First operational use of an RL10 engine equipped with 3D-printed components
- 2022 A single RL10 powered the Interim Cryogenic Propulsion Stage on the first SLS mission
Specifications
RL10 Model |
RL10B-2 |
RL10A-4-2 |
RL10C-1 |
RL10C-1-1 |
RL10C-X |
RL10C-3 |
Launch Vehicle: | Delta IV | Atlas V | Atlas V | Atlas V, Vulcan Centaur | Vulcan Centaur | SLS Exploration Upper Stage |
Thrust: |
24,750 lbf |
22,300 lbf |
22,890 lbf |
23,825 lbf |
24,120 lbf |
24,340 lbf |
Weight: |
664 lbs |
370 lbs |
420 lbs |
415 lbs |
510 lbs |
508 lbs |
Fuel: |
Liquid hydrogen |
Liquid hydrogen |
Liquid hydrogen |
Liquid hydrogen |
Liquid hydrogen |
Liquid hydrogen |
Oxidizer: |
Liquid oxygen |
Liquid oxygen |
Liquid oxygen |
Liquid oxygen |
Liquid oxygen |
Liquid oxygen |
Nominal Mixture Ratio: |
5.88:1 |
5.5:1 |
5.5:1 |
5.5:1 |
5.5:1 |
5.7:1 |
Specific Impulse: |
465.5 sec |
451.0 sec |
449.7 sec |
453.8 sec |
460.9 sec |
460.1 sec |
Length: |
86.5" (stowed) |
90" |
86" |
96.7" |
130.4" |
124.3" |
Nozzle Diameter: |
84.5" |
46" |
57" |
62" |
73.7" |
73" |
Videos
News Updates
- November 10, 2022 - Aerojet Rocketdyne Propulsion Systems Enable Launch of Severe Weather Forecasting Satellite
- October 4, 2022 - Aerojet Rocketdyne Propulsion Helps Propel ULA Atlas V Rocket to Deliver Two Commercial Satellites to Orbit
- July 1, 2022 - Aerojet Rocketdyne Propulsion Critical to Launch of U.S. Space Force Missile Early Warning Satellite
- April 11, 2022 - Aerojet Rocketdyne Secures its Largest RL10 Engine Contract from United Launch Alliance
- May 18, 2021 - RL10 Notches Key 3D-printing Milestone With Atlas V Launch
- May 11, 2021 - 3D Printed RL10C-X Engine Demonstrates Full Mission Capability During Altitude Hot Fire Test Series
- April 26, 2021 - Aerojet Rocketdyne Powers Launch of ULA's Delta IV Heavy to Orbit
- December 2020 - Aerojet Rocketdyne RL10 Engines Set Stage for SLS Evolution
- Aug. 7, 2020 - Aerojet Rocketdyne to Provide ULA’s Vulcan Centaur Key Propulsion for Next Generation of Air Force Launch Services
- July 28, 2020 - NASA Perseverance’s Mission to Mars Propelled by Aerojet Rocketdyne
- July 20, 2020 - Aerojet Rocketdyne Completes its Propulsion for NASA’s Artemis II Mission
- May 17, 2020 - Aerojet Rocketdyne Powers Second Mission for U.S. Space Force
- March 26, 2020 - AEHF-6 Launch Marks 500th Flight of Aerojet Rocketdyne’s RL10 Engine
- Feb. 12, 2020 - NASA’s Artemis I Progresses Toward Launch
- Feb. 9, 2020 - Solar Orbiter Soars Thanks to Aerojet Rocketdyne Propulsion
- Feb. 3, 2020 - Aerojet Rocketdyne Delivers RL10 Engines That Will Help Send NASA Astronauts to Deep Space