RL10

The RL10 is a <a href="/facts/Liquid-fuel_rocket/TAonrVDn">liquid-fuel</a> <a href="/facts/Cryogenic_rocket_engine/MCUrNQ51">cryogenic rocket engine</a> built in the <a href="/facts/United_States/P0sCdLe5">United States</a> by <a href="/facts/Aerojet_Rocketdyne/hN0hGfHI">Aerojet Rocketdyne</a> that burns <a href="/facts/Cryogenic_fuel/4RHxUvG8">cryogenic</a> <a href="/facts/Liquid_hydrogen/Vpk3Gb8P">liquid hydrogen</a> and <a href="/facts/Liquid_oxygen/qnI0KDTb">liquid oxygen</a> propellants. Modern versions produce up to 110 kN (24,729 lbf) of <a href="/facts/Thrust/EM04CqV7">thrust</a> per engine in vacuum. RL10 versions were produced for the <a href="/facts/Centaur_(rocket_stage)/ryg96uIF">Centaur</a> <a href="/facts/Upper_stage/WNrmgztj">upper stage</a> of the <a href="/facts/Atlas_V/5SNgegyt">Atlas V</a> and the <a href="/facts/Delta_Cryogenic_Second_Stage/Jn3zchkc">DCSS</a> of the <a href="/facts/Delta_IV/QWun0yHh">Delta IV</a>. More versions are in development or in use for the <a href="/facts/Exploration_Upper_Stage/7aeSEWkR">Exploration Upper Stage</a> of the <a href="/facts/Space_Launch_System/DbGCgH1W">Space Launch System</a> and the Centaur V of the <a href="/facts/Vulcan_(rocket)/ItQaJHkk">Vulcan</a> rocket.
The <a href="/facts/Expander_cycle/vUu8MYyj">expander cycle</a> that the engine uses drives the <a href="/facts/Turbopump/D6L2o2Yk">turbopump</a> with waste heat absorbed by the engine combustion chamber, throat, and nozzle. This, combined with the hydrogen fuel, leads to very high <a href="/facts/Specific_impulse/JKGgw2I4">specific impulses</a> (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.

RL10 open-in-new

RL10