RD-0216
The RD-0216 and RD-0217 are liquid rocket engines, burning N2O4 and UDMH in the oxidizer rich staged combustion cycle. The only difference between the RD-0216 and the RD-0217 is that the latter has a heat exchanger to heat the pressuring gasses for the tanks. Three RD-0216 and one RD-0217 were used on the first stage of the UR-100 ICBM. The engines were manufactured until 1974 and stayed in operational use until 1991. More than 1100 engines were produced.
For the UR-100N project, while first stage propulsion was based on the more powerful RD-0233 engine. The second stage used a variation of the RD-0217 called the RD-0235. It used a vacuum optimized nozzle extension, and thus had an extra 10s of isp and of more thrust. It has a fixed nozzle and relies on the RD-0236 vernier engine for thrust vectoring. While the engine has been out of production for a while, the UR-100NU and the Rokot and Strela use it as of 2015.
