Space Shuttle Main Engines ;Pratt & Whitney Rocketdyne •
RL10 (
LH2/
LOX) An
American Society of Mechanical Engineers (ASME) Historic Landmark developed by
Pratt & Whitney. Used on the
Saturn I, the upper stage of the
Delta IV, the
Centaur upper stage for the
Atlas and
Titan rockets and on the vertical-landing
McDonnell Douglas DC-X "Delta Clipper". It was intended to serve as the main propulsion engine for the
Altair lunar lander. Currently in use on the
Atlas V,
Vulcan Centaur,
Space Launch System Block 1, and in the future, Space Launch System Block 1B and Block 2. (
Centaur III,
Centaur V, Interim Cryogenic Propulsion System, and
Exploration Upper Stage respectively. •
RS-68 (
LH2/
LOX) First stage engine for the
Delta IV. •
RS-25 (
LH2/
LOX)
Space Shuttle main engine. • SJ61 (
JP-7/ingested air) A dual-mode
ramjet/
scramjet engine flown on the
Boeing X-51 hypersonic demonstration vehicle. •
J-2X (LH2/LOX) Previously developed to be used on the
Earth Departure Stage for the Block II of the
Space Launch System, though the EDS was later replaced by the Exploration Upper Stage using 4 RL10 engines. ==See also==