|In service||21 July 1967 (document №705-235)–1974|
|Used by||Soviet Union|
|Manufacturer||design by OKB-52 of V.N.Chelomey, production by Khrunichev Machine-Building Plant, Omsk aviation facility №166 "Polyot", Orenburg aviation facility №47 "Strela"|
|Blast yield||1 Mt by NII-1011, Chelyabinsk-70|
|Engine||two-stage liquid fuel|
|Accuracy||1000–1400 metres CEP|
The UR-100 (Russian: УР-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 (Russian: Универсальная Ракета). 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 are based on it.
The similar designation UR-100MR (Russian: УР-100МР) actually refers to an entirely different missile, the MR-UR-100 Sotka (SS-17 Spanker).
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, un-manned 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.
The Strela and Rokot carrier rockets are based on the UR-100.