
thumb|right| The RD-250 (, GRAU index: 8D518) is the base version of a dual-nozzle family of liquid-fuel rocket engines, burning a hypergolic mixture of unsymmetrical dimethylhydrazine (UDMH) fuel with dinitrogen tetroxide () oxidizer in a gas-generator open cycle. The RD-250 was developed by OKB-456 for Yangel's PA Yuzhmash ICBM, the R-36 (8K67). Its variations were also used on the Tsyklon-2 and Tsyklon-3 launch vehicles. It was supposed to be used on the Tsyklon-4, but since the cancellation of the project it should be considered as out of production.
via Wikipedia infobox
thumb|right| The RD-250 (, GRAU index: 8D518) is the base version of a dual-nozzle family of liquid-fuel rocket engines, burning a hypergolic mixture of unsymmetrical dimethylhydrazine (UDMH) fuel with dinitrogen tetroxide () oxidizer in a gas-generator open cycle. The RD-250 was developed by OKB-456 for Yangel's PA Yuzhmash ICBM, the R-36 (8K67). Its variations were also used on the Tsyklon-2 and Tsyklon-3 launch vehicles. It was supposed to be used on the Tsyklon-4, but since the cancellation of the project it should be considered as out of production.
==Versions== The engine has seen different versions made: RD-250 (GRAU index: 8D518): Base engine of the family. Used on the R-36. A bundle of three RD-250 form the RD-251 cluster. RD-250P (GRAU index: 8D518P): Improved version of the RD-250. Used on the R-36P. A bundle of three RD-250P form the RD-251P cluster. RD-250M (GRAU index: 8D518M): Improved version of the RD-250P. Used on the R-36-O. A bundle of three RD-250M form the RD-251M cluster. RD-250PM (GRAU index: 8D518PM): Improved version of the RD-250M. Used on the Tsyklon-3. A bundle of three RD-250PM form the RD-261 cluster. RD-252 (GRAU index: 8D724): Vacuum optimized version of the RD-250. Used on the R-36 and Tsyklon-2 second stages. RD-262 (GRAU index: 11D26): Improved version of the RD-252. Used on the Tsyklon-3 second stages.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).