RD-250


The RD-250 is the base version of a dual-nozzle family of liquid rocket engines, burning N2O4 and UDMH in the oxidizer rich staged combustion cycle. The RD-250 was developed by OKB-456 for Yangel's PA Yuzhmash ICBM, the R-36. 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:
Some of these engines were bundled into modules of multiple engines. The relevant modules and auxiliary engines are:

Possible technological transfer to North Korea

Several experts think that technology from the RD-250 engine could have been transferred to North Korea. This transfer would explain the rapid progress of North Korea in the development of two new missiles: the intermediate-range Hwasong-12 and the intercontinental ballistic missile, Hwasong-14. Due to complexity of the technology involved in this type of engine, modifications or reverse engineering seem difficult to achieve. Thus it's believable that complete hardware could have been bought on black market and directly shipped to North Korea, by Russia or Ukraine. Conversely, there is analysis suggesting an alternative mechanism for North Korea to receive R-36 missile engines, or an entire missile, from USSR or Russia.