RD-0233

The RD-0233 and RD-0234 are liquid-fueled rocket engines which burn a hypergolic mixture of unsymmetrical dimethylhydrazine fuel with dinitrogen tetroxide oxidizer in an Staged combustion [cycle (rocket)|oxidizer-rich staged combustion] cycle. The only difference between the RD-0233 and the RD-0234 is that the latter has a heat exchanger to heat the pressuring gasses for the tanks. Three RD-0233 and one RD-0234 are used on the first stage of the UR-100UTTKh ICBM. While the engine is out of production, the ICBM as well as Rokot and Strela remain operational as of 2015.