28 Rocket engines using hydrogen propellant

A cryogenic rocket engine is a rocket engine that uses a cryogenic fuel and oxidizer, that is, both its fuel and oxidizer are gases liquefied and stored at very low temperatures. These highly efficient engines were first flown on the US Atlas-Centaur and were one of the main factors of NASA's success in reaching the Moon by the Saturn V rocket.

The BE-3 is a LH2/LOX rocket engine developed by Blue Origin.

The BE-3 is a LH2/LOX rocket engine developed by Blue Origin.

The CE-7.5 is a cryogenic rocket engine developed by the Indian Space Research Organisation to power the upper stage of its GSLV Mk-2 launch vehicle. The engine was developed as a part of the Cryogenic Upper Stage Project (CUSP). It replaced the KVD-1 (RD-56) Russian cryogenic engine that powered the upper stage of GSLV Mk-1.

The CE-20 is a cryogenic rocket engine developed by the Liquid Propulsion Systems Centre, a subsidiary of Indian Space Research Organisation. It has been developed to power the upper stage of the Geosynchronous Satellite Launch Vehicle Mk III. It is the first Indian cryogenic engine to feature a gas-generator cycle. The high thrust cryogenic engine is one of the most powerful upper stage cryogenic engines in the world.

The Delta Cryogenic Second Stage (DCSS) is a family of cryogenic rocket stages used on the Delta III and Delta IV rockets, and which is planned to be used on the Space Launch System Block 1. The stage consists of a cylindrical LH2 tank structurally separated from an oblate spheroid LOX tank. The LH2 tank cylinder carries payload launch loads, while the LOX tank and engine are suspended below within the rocket's inter-stage. The stage is powered by a single Pratt & Whitney RL10B-2 engine, which features an extendable carbon-carbon nozzle to improve specific impulse.

The HM7B is a European cryogenic upper stage rocket engine used on the vehicles in the Ariane rocket family. It will be replaced by Vinci, which will act as the new upper stage engine on Ariane 6. Nearly 300 engines have been produced to date.

The integrated powerhead demonstrator (IPD) was a U.S. Air Force project in the 1990s and early 2000s run by NASA and the Air Force Research Laboratory (AFRL) to develop a new rocket engine front-end that would utilize a full flow staged combustion cycle (FFSCC). The prime contractors were Rocketdyne and Aerojet.

The J-2 was a liquid-fuel cryogenic rocket engine used on NASA's Saturn IB and Saturn V launch vehicles. Built in the U.S. by Rocketdyne, the J-2 burned cryogenic liquid hydrogen (LH2) and liquid oxygen (LOX) propellants, with each engine producing 1,033.1 kN (232,250 lbf) of thrust in vacuum. The engine's preliminary design dates back to recommendations of the 1959 Silverstein Committee. Rocketdyne won approval to develop the J-2 in June 1960 and the first flight, AS-201, occurred on 26 February 1966. The J-2 underwent several minor upgrades over its operational history to improve the engine's performance, with two major upgrade programs, the de Laval nozzle-type J-2S and aerospike-type J-2T, which were cancelled after the conclusion of the Apollo program.

The J-2X is a liquid-fueled cryogenic rocket engine that was planned for use on the Ares rockets of NASA's Constellation program, and later the Space Launch System. Built in the United States by Aerojet Rocketdyne, the J-2X burns cryogenic liquid hydrogen and liquid oxygen propellants, with each engine producing 1,307 kN (294,000 lbf) of thrust in vacuum at a specific impulse (Isp) of 448 seconds (4.39 km/s). The engine's mass is approximately 2,470 kg, significantly heavier than its predecessors.

The LE-5 liquid rocket engine and its derivative models were developed in Japan to meet the need for an upper stage propulsion system for the H-I and H-II series of launch vehicles. It is a bipropellant design, using LH2 and LOX. Primary design and production work was carried out by Mitsubishi Heavy Industries. In terms of liquid rockets, it is a fairly small engine, both in size and thrust output, being in the 89 kN (20,000 lbf) and the more recent models the 130 kN (30,000 lbf) thrust class. The motor is capable of multiple restarts, due to a spark ignition system as opposed to the single use pyrotechnic or hypergolic igniters commonly used on some contemporary engines. Though rated for up to 16 starts and 40+ minutes of firing time, on the H-II the engine is considered expendable, being used for one flight and jettisoned. It is sometimes started only once for a nine-minute burn, but in missions to GTO the engine is often fired a second time to inject the payload into the higher orbit after a temporary low Earth orbit has been established.

The LE-5 liquid rocket engine and its derivative models were developed in Japan to meet the need for an upper stage propulsion system for the H-I and H-II series of launch vehicles. It is a bipropellant design, using LH2 and LOX. Primary design and production work was carried out by Mitsubishi Heavy Industries. In terms of liquid rockets, it is a fairly small engine, both in size and thrust output, being in the 89 kN (20,000 lbf) and the more recent models the 130 kN (30,000 lbf) thrust class. The motor is capable of multiple restarts, due to a spark ignition system as opposed to the single use pyrotechnic or hypergolic igniters commonly used on some contemporary engines. Though rated for up to 16 starts and 40+ minutes of firing time, on the H-II the engine is considered expendable, being used for one flight and jettisoned. It is sometimes started only once for a nine-minute burn, but in missions to GTO the engine is often fired a second time to inject the payload into the higher orbit after a temporary low Earth orbit has been established.

The LE-5 liquid rocket engine and its derivative models were developed in Japan to meet the need for an upper stage propulsion system for the H-I and H-II series of launch vehicles. It is a bipropellant design, using LH2 and LOX. Primary design and production work was carried out by Mitsubishi Heavy Industries. In terms of liquid rockets, it is a fairly small engine, both in size and thrust output, being in the 89 kN (20,000 lbf) and the more recent models the 130 kN (30,000 lbf) thrust class. The motor is capable of multiple restarts, due to a spark ignition system as opposed to the single use pyrotechnic or hypergolic igniters commonly used on some contemporary engines. Though rated for up to 16 starts and 40+ minutes of firing time, on the H-II the engine is considered expendable, being used for one flight and jettisoned. It is sometimes started only once for a nine-minute burn, but in missions to GTO the engine is often fired a second time to inject the payload into the higher orbit after a temporary low Earth orbit has been established.

The LE-7 and its succeeding upgrade model the LE-7A are staged combustion cycle LH2/LOX liquid rocket engines produced in Japan for the H-II series of launch vehicles. Design and production work was all done domestically in Japan, the first major (main/first-stage) liquid rocket engine with that claim, in a collaborative effort from the National Space Development Agency (NASDA), Aerospace Engineering Laboratory (NAL), Mitsubishi Heavy Industries, and Ishikawajima-Harima. NASDA and NAL have since been integrated into JAXA. However, a large part of the work was contracted to Mitsubishi, with Ishikawajima-Harima providing turbomachinery, and the engine is often referred to as the Mitsubishi LE-7(A).

The LR87 was an American liquid-propellant rocket engine, which was used on the first stages of Titan intercontinental ballistic missiles and launch vehicles. Composed of twin motors with separate combustion chambers and turbopump machinery, it is considered a single unit. The LR87 first flew in 1959.

Aerojet's M-1 was the largest and most powerful liquid-hydrogen-fueled liquid-fuel rocket engine to be designed and component-tested. The M-1 offered a baseline thrust of 6.67 MN and 8 MN as its immediate growth target. If built, the M-1 would be larger and more efficient than the famed F-1 that powered the first stage of the Saturn V rocket to the Moon.

The XLR-129 was an American rocket engine design that would have used liquid hydrogen and liquid oxygen propellants. It was developed by Pratt & Whitney and initially was to develop 250,000 lbf (1,100 kN) of thrust. It featured an expanding nozzle in order to tune performance over a wide range of altitudes.

The Soviet RD-0120 was the Energia core rocket engine, fueled by LH2/LOX, roughly equivalent to the Space Shuttle Main Engine (SSME). These were attached to the Energia core rather than the orbiter, so were not recoverable after a flight, but created a more modular design. The RD-0120 and the SSME have both similarities and differences. The RD-0120 achieved a slightly higher specific impulse and combustion chamber pressure with reduced complexity and cost, as compared to the SSME. It uses a fuel-rich staged combustion cycle and a single shaft to drive both the fuel and oxidizer turbopumps. Some of the Russian design features, such as the simpler and cheaper channel wall nozzles, were evaluated by Rocketdyne for possible upgrades to the SSME. It achieved combustion stability without the acoustic resonance chambers that the SSME required.

The RD-0146 is a Russian cryogenic rocket engine. The RD-0146 engine was developed by KBKhA design bureau in Voronezh, Russia, in cooperation with the American Pratt & Whitney Rocketdyne company. In 2009, it came into prominence, as Russian space agency chose it for the second-stage of the proposed Rus-M launch vehicle designed to carry the future Russian PPTS crewed spacecraft. After the cancellation of Rus-M rocket, the RD-0146D variant was selected as the powerplant for the KVTK upper stage.

SABRE is a concept under development by Reaction Engines Limited for a hypersonic precooled hybrid air-breathing rocket engine. The engine is being designed to achieve single-stage-to-orbit capability, propelling the proposed Skylon spaceplane to low Earth orbit. SABRE is an evolution of Alan Bond's series of LACE-like designs that started in the early/mid-1980s for the HOTOL project.

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, the upper stage of the OmegA rocket, and the Centaur V of the Vulcan rocket.

The Aerojet Rocketdyne RS-68 is a liquid-fuel rocket engine that uses liquid hydrogen (LH2) and liquid oxygen (LOX) as propellants in a gas-generator power cycle. It is the largest hydrogen-fueled rocket engine ever flown.

The Aerojet Rocketdyne RS-25, also known as the Space Shuttle main engine (SSME), is a liquid-fuel cryogenic rocket engine that was used on NASA's Space Shuttle. NASA is planning to continue using the RS-25 on the Space Shuttle's successor, the Space Launch System (SLS).

The TR-106 or low-cost pintle engine (LCPE) was a developmental rocket engine designed by TRW under the Space Launch Initiative to reduce the cost of launch services and space flight. Operating on LOX/LH2 the engine had a thrust of 2892 kN, or 650,000 pounds, making it one of the most powerful engines ever constructed.

Vinci is a European Space Agency cryogenic liquid rocket engine currently under development. It is designed to power the new upper stage of Ariane 6.

Vulcain is a family of European first stage rocket engines for Ariane 5 and the future Ariane 6. Its development began in 1988 and the first flight was completed in 1996. The updated version of the engine, Vulcain 2, was first successfully flown in 2005. Both members of the family use liquid oxygen/liquid hydrogen cryogenic fuel. The new version under development for Ariane 6 will be called Vulcain 2.1.

The YF-73 was China's first successful cryogenic liquid hydrogen fuel and liquid oxygen oxidizer gimballed engine. It was used on the Long March 3 H8 third stage, running on the simple gas generator cycle and with a thrust of 44.15 kilonewtons (9,930 lbf). It had four hinge mounted nozzles that gimbaled each on one axis to supply thrust vector control and was restart capable. It used cavitating flow venturis to regulate propellant flows. The gas generator also incorporated dual heat exchangers that heated hydrogen gas, and supplied helium from separate systems to pressurize the hydrogen and oxygen tanks. The engine was relatively underpowered for its task and the start up and restart procedures were unreliable. Thus, it was quickly replaced by the YF-75.