NK-15

The NK-15 (GRAU index 11D51) was a rocket engine designed and built in the late 1960s by the Kuznetsov Design Bureau. The NK designation was derived from the initials of chief designer Nikolay Kuznetsov. The NK-15 was among the most powerful LOX/kerosene rocket engines when it was built, with a high specific impulse and low structural mass. It was intended for the ill-fated Soviet N-1 Moon rocket.

History
The engine equipped the N1 rocket - the first two launch attempts failed due to this engine. Its successor the NK-33 was to be used on the N1F, a new version of the N1, but the program was cancelled.

Versions

 * NK-15V (GRAU index 11D52): Modified NK-15 optimized for vacuum operation, used on the N1 second stage.