Rocket engines using full flow staged combustion cycle

family of cryogenic methane-fueled rocket engines developed by SpaceX

RD-270 (, GRAU index: 8D420) was a single-chamber liquid-fuel rocket engine designed by Energomash (USSR) in 1960–1970. It was to be used on the first stages of the proposed heavy-lift UR-700 and UR-900 rocket families, as well as on the N1. It has the highest thrust among single-chamber engines of the USSR, 640 metric tons at the surface of Earth. The propellants used are a hypergolic mixture of unsymmetrical dimethylhydrazine (UDMH) fuel with dinitrogen tetroxide () oxidizer. The chamber pressure was among the highest considered, being about 26 MPa. This was achieved by applying the full-flo

U.S. Air Force project in the 1990s and early 2000s