For the requirements to have storable propellants and higher thrust, Glushko's OKB-456 developed the RD-211, which had four combustion chambers, each having twice the thrust of the RD-100, a Russian adaptation of the V-2 A-4 engine.[5] The four chambers were fed from a single turbopump powered by steam generated from catalytic decomposition of hydrogen peroxide.[6] When then came the requirement for the Burancruise missile project, a version for that application was developed in the RD-212.[7] Both RD-211 and RD-212 proved too weak for the application and the project were abandoned for the RD-213 for Buran.[8] When Yangel's OKB-586 was tasked with developing the first storable propellant ballistic missile in the Soviet arsenal, the RD-211 proved too weak. Thus, the project was definitely abandoned and the more powerful RD-214 was developed.[2] While Korolev's refusal to use toxic propellants basically left him out of the ballistic missile development race, the basic design of the RD-211 also served as basis for the RD-107/RD-108 engine, which went to be the most flown rocket engines in history.[5]
The initial R-12 was a pad launched missile. It had significant operative issues on readiness and vulnerability. Thus, the silo launched R-12U was developed. For this development the RD-214U was developed. When Yangel used the R-12U as the basis for the Kosmos-2 63S1, the RD-214F was developed and fire tested, but in the end the stock R-12U was used as first stage. So it was for all subsequent 63S1M and 11K63.[1][5][9]
Versions
This engine many versions:
RD-211: GRAU Index 8D57. Original design for the R-12. Based on the RD-100, itself an adaptation of the V-2 A4 engine. This engine already had four separate combustion chambers, an H2O2 steam driven turbine and required vanes in the exhaust to control the rocket.[1][6]
RD-212: GRAU Index 8D41. Originally developed from the RD-211 for the Burancruise missile project. Project drop in favor of RD-213 due to insufficient thrust.[1][7]
RD-213: GRAU Index 8D13. Similar to the RD-214. Developed for the Burancruise missile project. Cancelled with the project.[1][8]
RD-214: GRAU Index 8D59. Original version of the engine designed for the R-12 (8K63).[1]
RD-214U: GRAU Index 8D59. Improved version of the engine. Flew on the R-12U (8K63S) and Kosmos-2 (11K63) launch vehicle.[1]
RD-214F: GRAU Index 11D45. Project for the initial version of Kosmos-2 (63S1).[1]