The UR-100N is a fourth-generation silo-launched liquid-propellant ICBM similar to the UR-100 but with much increased dimensions, weights, performance, and payload. The missile was not designed to use existing UR-100 silos, and therefore had new silos constructed for it.
| UR-100N | |
|---|---|
| Type | ICBM |
| Service history | |
| In service | 1982–present |
| Used by | Soviet Union / CIS |
| Production history | |
| Manufacturer | Khrunichev Machine-Building Plant |
| Specifications | |
| Weight | 105.6 tonnes |
| Length | 27 metres |
| Diameter | 2.5 m |
| | |
| Warhead | up to 6 (1 as per START II |
| Blast yield | 550 KT (Mod 3), 5 MT (Mod 2) |
| | |
| Engine | two-stage liquid fuel |
| Operational range | 10,000 km |
| Guidance system | inertial |
The UR-100N reached initial operating capability in 1974, and by 1978 an inventory of 190 launchers were reached. In 1979, the UR-100UTTH became operational and by 1983 had replaced many older missiles and reached maximum inventory of 360 launchers. This had fallen to 300 by 1991, and with the dissolution of the Soviet Union, many in Ukraine became property of that nation. 170 remained in Russia, although treaty obligations required the rearming of the missiles with single warheads. Russia retains some UR-100UTTHs in its inventory with the potential to retain as many as fifty by the end of the decade. Recent political developments have led to plans to rearm the missiles again with MIRV warheads.
The units previously held by Ukraine have been returned to Russia or decommissioned.
In December 2008 Strategic rocket forces had 126 UR-100NUTTH operational missiles. This does not, however, make them the most numerous ICBMs in the Russian arsenal; that distinction belongs to SS-25 ICBMs.
The UR-100N forms the basis of the Rockot space launch system, which was used in several successful launches in the 1990s and early 2000s, and one failed launch of the ESA CryoSat satellite in 2005. After the failure, Rockot launches were suspended. Once the cause was unambiguously identified and corrective measures implemented, Rockot returned to active service on 28 July 2006, with the successful launch of an earth observation satellite for South Korea.
