The UR-100 was an intercontinental ballistic missile (ICBM) developed and deployed by the Soviet Union from 1966 to 1996. UR (УР) in its designation stood for Universal Rocket. It was known during the Cold War by the NATO reporting name SS-11 Sego and internally by the GRAU index 8K84. The Strela and Rokot carrier rockets were based on it. The similar designation UR-100MR actually refers to an entirely different missile, the MR-UR-100 Sotka (SS-17 Spanker).

Description

The UR-100 was a two-stage liquid-propellant lightweight ICBM. Initial versions carried a single warhead of 0.5 to 1.1 Mt yield, while later versions could carry three or six MIRV warheads. The missile was silo-launched. 15P784 silo design (by KBOM, Design Bureau of Common Machinery, of V.P.Barmin) was greatly simplified in comparison to earlier missiles. Facilities consisted of hardened, unstaffed silos controlled by a single central command post. This was the first soviet ICBM (8K84M, entered service on 3 October 1971) equipped with missile defense countermeasure "Palma" by NII-108 of V.Gerasimenko.

Variants and developments

Operational history

Formations included:

As a space launcher

The Strela and Rokot carrier rockets are based on the UR-100.