RL10

RL10
An RL10A-4 engine in London's Science Museum
Country of originUnited States
First flight1962 (1962) (RL10A-1)
ManufacturerAerojet Rocketdyne
ApplicationUpper stage engine
Associated LVAtlas · Delta III · Delta IV · Saturn I · SLS · Titan IIIE · Titan IV · Vulcan Centaur
Canceled: DC-X · OmegA · Space Shuttle
StatusIn production
Liquid-fuel engine
PropellantLOX / LH2
Mixture ratio5.88:1
CycleExpander cycle
Configuration
Nozzle ratio84:1 or 280:1
Performance
Thrust, vacuum110.1 kN (24,800 lbf)
Specific impulse, vacuum465.5 s (4.565 km/s)
Dimensions
Length4.15 m (13.6 ft) w/ nozzle extended
Diameter2.15 m (7 ft 1 in)
Dry mass301 kg (664 lb)
Used in
Centaur, DCSS, S-IV
References
References[1]
NotesPerformance values and dimensions are for RL10B-2.

The RL10 is a liquid-fuel cryogenic rocket engine built in the United States by Aerojet Rocketdyne that burns cryogenic liquid hydrogen and liquid oxygen propellants. Modern versions produce up to 110 kN (24,729 lbf) of thrust per engine in vacuum. Three RL10 versions are in production for the Centaur upper stage of the Atlas V and the DCSS of the Delta IV. Three more versions are in development for the Exploration Upper Stage of the Space Launch System and the Centaur V of the Vulcan rocket.[2]

The expander cycle that the engine uses drives the turbopump with waste heat absorbed by the engine combustion chamber, throat, and nozzle. This, combined with the hydrogen fuel, leads to very high specific impulses (Isp) in the range of 373 to 470 s (3.66–4.61 km/s) in a vacuum. Mass ranges from 131 to 317 kg (289–699 lb) depending on the version of the engine.[3][4]

  1. ^ Cite error: The named reference EA10B2 was invoked but never defined (see the help page).
  2. ^ Cite error: The named reference Aerojet Rocketdyne 2 was invoked but never defined (see the help page).
  3. ^ "RL-10C". www.astronautix.com. Archived from the original on December 28, 2016. Retrieved April 6, 2020.
  4. ^ "RL-10A-1". www.astronautix.com. Archived from the original on December 28, 2016. Retrieved April 6, 2020.