MKBS

MKBS, a proposed Soviet space station cancelled in 1974. This was to be the centerpiece of a broader initiative called MOK, which envisioned a whole system of orbital complexes with the MKBS acting as the central hub for crew transfers and control.

The MKBS would be launched in parts by N1s. Both modules were roughly the size of Skylab. Linking them was a segment that could rotate, providing a small amount of artificial gravity to two cylindrical modules. Attached to that on a boom would have been a nuclear reactor.