N1 Block B is the second stage of the N1-LK-LOK. Created and designed with the scope of competing with the Saturn V, the N1 was to launch its first crewed mission somewhere in 1975. The N1-L3 program was eventually cancelled due to the failures of the first 4 launches. The shape of the stage is due to the placement of its fuel tanks and engines.
- This was part of the Soviet planned "Moon rocket", which was never successfully used.
- It may be used as station engine.