In 1961, faced with the prospect of development in the United States of an anti-ballistic missile (ABM) system to intercept conventional ICBMs, the Soviet Union began development of a fractional orbital bombardment system (FOBS) to defeat these interceptors. The concept was to include launching a missile into orbit (150 km), from where a warhead could be dropped to its targets in a non-ballistic manner, and without giving away its target until final descent. Three Soviet design centers developed proposals for the system, with OKB-1 (S. P. Korolev) proposing the Global Rocket 1.
The GR-1 was a liquid cryogenic propellant fuelled rocket. It was intended to utilize the launch pads of the R-9 Desna which was being phased out of service. The GR-1 project was cancelled in 1964 citing engine delays, a fate which became permanent for all of the FOBS designs after the SALT II agreement of 1979. Even earlier, in 1972, the Anti-Ballistic Missile Treaty removed the primary reason for such a weapon.