RL-10 Upper Stage Engine Family
Aerojet Rocketdyne (L3Harris)
Liquid hydrogen / liquid oxygen upper-stage engine family powering Atlas V, Delta IV Heavy, Vulcan Centaur and NASA SLS, in service for six decades.
Key figurescomparable across the catalogue
- Mass
- 167 kg
- Thrust
- 99,200 N
- Specific impulse
- 450.5 s
Normalised to common units so this product can be compared with others in its category. The supplier's own wording is below.
As published by the supplier
- Propellants
- Fuel: liquid hydrogen; Oxidizer: liquid oxygen
- RL10B-2 / RL10C-2-1 (Delta IV)
- Thrust 24,750 lbf; weight 664 lbs; MR 5.88:1; Isp 465.5 s; length 86.5 in stowed / 163.5 in deployed; nozzle diameter 84.5 in
- RL10A-4-2 (Atlas V)
- Thrust 22,300 lbf; weight 370 lbs; MR 5.5:1; Isp 451.0 s; length 90 in; nozzle diameter 46 in
- RL10C-1 (Atlas V)
- Thrust 22,890 lbf; weight 420 lbs; MR 5.5:1; Isp 449.7 s; length 86 in; nozzle diameter 57 in
- RL10C-1-1 (Atlas V, Vulcan Centaur)
- Thrust 23,825 lbf; weight 415 lbs; MR 5.5:1; Isp 453.8 s; length 96.7 in; nozzle diameter 62 in
- RL10C-X (Vulcan Centaur)
- Thrust 24,120 lbf; weight 510 lbs; MR 5.5:1; Isp 460.9 s; length 130.4 in; nozzle diameter 73.7 in
- RL10C-3 (SLS Exploration Upper Stage)
- Thrust 24,340 lbf; weight 508 lbs; MR 5.7:1; Isp 460.1 s; length 124.3 in; nozzle diameter 73 in
- Throttling
- Demonstrated 104% down to 5.9% of rated power (17.6:1 range)
- First test
- 1959; first Atlas Centaur flight 1963
About
For six decades, L3Harris’ 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 two spacecraft to reach interstellar space.
Today, multiple RL10 variants carry the engine’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 uncrewed 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.
L3Harris has developed and is working to qualify a modern version of the engine known as the RL10C-X that includes major components built using 3D 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. In 2010 the engine demonstrated deep-throttling from 104 percent of rated power down to 5.9 percent, an unprecedented thrust range of 17.6:1. The 500th RL10 engine flight took place in 2020.
Documentation
No public datasheet yet — request the datasheet / ICD from the supplier.