The RD-263 (, GRAU index: 15D117) is a liquid-fuel rocket engine, burning a hypergolic mixture of unsymmetrical dimethylhydrazine (UDMH) fuel with dinitrogen tetroxide () oxidizer in the oxidizer rich staged combustion cycle. Four RD-263 engines form a propulsion module RD-264 (GRAU index: 15D119). For the R-36M KB Yuzhnoye only ordered the first stage propulsion to Energomash, instead of both stages, arguing that they were overworked with the RD-270 development. By April 1970 Yuzhnoye was getting the engine documentation. By the end of 1972 Energomash started to test fire the engines in its own test stand. And by September 1973 the engine was certified for flight. While the engine is out of production, the ICBM as well as the Dnepr remain operational as of 2015.
Versions The basic engine has been used for the RD-263 (GRAU index: 15D117): Initial version used on the R-36M and R-36MUTTKh first stage (15А14 and 15A18). RD-268 (GRAU index: 15D168): Variation used on the MR-UR-100 (15А15) and MR-UR-100UTTKh (15A16) first stage. RD-273 (AKA RD-263F): Improved version based on the RD-263F upgrade project. Version used on the R-36M2 (15A18M) and (15A18M2) first stage.
+ RD-0210 family of engines Engine RD-263 RD-268 RD-273 AKA 15D117 15D168 RD-263F Propulsion module RD-264 N/A RD-274 Development 1969-1975 1970-1976 1982-1988 Engine type Liquid oxidizer rich staged combustion using N2O4/UDMH propellant with an O/F ratio of 2.67 Combustion chamber pressure Thrust, vacuum Thrust, sea level I, vacuum 318s 318.5s 318s I, sea level 293s 295.6s 296s Length Width Dry weight Unknown Use R-36M (15А14) and R-36MUTTKh (15A18) core stage MR-UR-100 (15А15) and MR-UR-100UTTKh (15A16) first stage R-36M2 (15A18M) and (15A18M2) first stage Status Out of production Retired Retired References
Modules Some of these engines were bundled into modules of multiple engines. The relevant modules and auxiliary engines are: RD-264 (GRAU Index 15D119): A module comprising four RD-263. Propulsion module of the R-36M and R-36MUTTKh first stage (15А14 and 15A18). RD-274 (GRAU Index ): A module comprising four RD-273. Propulsion module of the R-36M2 (15A18M) and (15A18M2) first stage.
See also
R-36M - ICBM for which this engine was originally developed. Dnepr - launch vehicle that is a repurposed R-36MUTTKh. LR-87, twin-chamber American rocket engine family used on the Titan series of US launch vehicles. Rocket engine using liquid fuel
References
External links KbKhA official information on the engine. (Archived) Encyclopedia Astronautica information on the propulsion module. (Archived)