Cryogenic Engines

Blue Origin's LH2/LOX engine — a combustion-tap-off variant (BE-3PM) powers the reusable New Shepard suborbital vehicle, and an upper-stage variant (BE-3U) flies on New Glenn.

Blue Origin's methane/LOX oxidizer-rich staged-combustion engine, which powers both the ULA Vulcan Centaur first stage and Blue Origin's own New Glenn booster.

ISRO's indigenous LH2/LOX cryogenic upper-stage engine, which powers the C25 upper stage of the LVM3 (GSLV Mk III).

A LH2/LOX upper-stage engine that powered the cryogenic upper stage (ESC-A) of Ariane 5 and earlier Ariane vehicles.

The restartable LH2/LOX engine of the Saturn V second and third stages and the Saturn IB second stage; its S-IVB restart sent Apollo crews toward the Moon.

A LH2/LOX staged-combustion engine that powers the first stage of Japan's H-IIA and H-IIB launch vehicles.

A large LH2/LOX expander-bleed-cycle engine developed for the first stage of Japan's H3 rocket, chosen for reliability and lower cost.

SpaceX's methane/LOX full-flow staged-combustion engine for Starship and its Super Heavy booster — one of very few full-flow engines ever flown, designed for rapid reuse. Thrust has risen across versions.

A long-serving expander-cycle LH2/LOX upper-stage engine (first flown in the 1960s) that powers the Centaur and DCSS upper stages and continues on Vulcan Centaur.

A reusable fuel-rich staged-combustion LH2/LOX engine developed for the Space Shuttle (as the SSME) and now expended on the SLS core stage; among the highest-efficiency hydrogen engines flown.

A large LH2/LOX gas-generator engine developed for the Delta IV; designed for lower cost than the SSME, it powered the Delta IV and Delta IV Heavy cores.

A restartable closed-expander-cycle LH2/LOX upper-stage engine developed for Ariane 6, enabling multiple burns for complex mission profiles.

The LH2/LOX gas-generator core engine of Ariane 5 (and, as Vulcain 2.1, of the Ariane 6 core stage).

China's first large LH2/LOX engine, two of which power the Long March 5 core stage.