| UR-100N SS-19 Stiletto | |
|---|---|
 | |
| Type | ICBM |
| Service history | |
| In service | 1975–present |
| Used by | RussianStrategic Missile Troops |
| Production history | |
| Designer | NPO Mashinostroyeniya |
| Manufacturer | Khrunichev Machine-Building Plant |
| Specifications | |
| Mass | 126.3 t (278,000 lb) |
| Length | 27.5 m (90 ft 3 in) |
| Diameter | 2.48 m (8 ft 2 in) |
| Warhead | 1 x 1Mt or 6 x 400kt[1] |
| Engine | two-stage liquid fuel |
Operational range | 10,600 kilometres (6,600 mi) |
| Maximum speed | 7.64 km/s (4.75 mi/s) |
Guidance system | inertial |
| Accuracy | CEP 300 m |
TheUR-100N (Russian:УР-100Н), also known asRS-18A, is anintercontinental ballistic missile in service withSoviet and RussianStrategic Missile Troops. The missile was given theNATO reporting nameSS-19 Stiletto and carries the industry designation15A30.[5]
Development of the UR-100N began atOKB-52 in 1970 and flight tests were carried out from 1973 through 1975. In 1976, the improvedUR-100NUTTKh (NATO designation SS-19 Mod 3) version entered development with flight tests in the later half of the decade. The rocket's control system was developed atNPO "Electropribor"[6] (Kharkiv,Ukraine).
The UR-100N is a fourth-generation silo-launched liquid-propellant ICBM similar to theUR-100 but with much increased dimensions, mass, performance, and payload. The missile was not designed to use existing UR-100 silos, and therefore had new silos constructed for it.
The missile has a preparation time to start of 25 minutes, a storage period of 22 years, and 6 MIRVs.[7]
The UR-100N reached initial operating capability in 1974, and by 1978 an inventory of 190 launchers were reached. In 1979, the UR-100UTTKh became operational and by 1983 had replaced many older missiles and reached a maximum inventory of 360 launchers. This had fallen to 300 by 1991, and with the dissolution of the Soviet Union, many inUkraine became property of that nation. 170 remained in Russia, although treaty obligations required the rearming of the missiles with single warheads. As of 2018, the Strategic Missile Troops had 20 (or more likely just 10) UR-100NUTTKh in active service.[8] Recent political developments have led to rearmament of the missiles with theAvangardhypersonic glide vehicles (HGVs) (NATO designationSS-19 Mod 4)[9][1] On 27 December 2019, the first missile regiment armed with theAvangard HGV officially entered combat duty.[10]
The units previously held by Ukraine have beenreturned to Russia or decommissioned.
US Air ForceNational Air and Space Intelligence Center estimates that as of June 2017 about 50 Mod 3 launchers were operationally deployed.[11]
The UR-100N forms the basis of theRokot spacelaunch system, which was used in several successful launches in the 1990s and early 2000s, and one failed launch of theESACryoSat satellite in 2005. After the failure, Rokot launches were suspended. Once the cause was unambiguously identified and corrective measures implemented, Rokot returned to active service on 28 July 2006, with the successful launch of an earth observation satellite for South Korea.
The START I treaty was signed by the Soviet Union in 1991. The treaty required the Soviet Union to begin the process of dismantling nuclear warheads and the launchers used for UR-100N missiles.[12] The Soviet Union had 300 100NUTTH missiles stationed in both Russia and Ukraine: 130 deployed in Ukraine, and the rest scattered around Russia.[13] After the fall of the USSR, Ukraine claimed ownership of all the missiles locating in its territory. Ukraine then began dismantling launchers for the UR-100N missiles in compliance with theSTART I treaty. Nuclear warheads that were deployed in Ukraine were also dismantled following terms of the treaty.[14]
TheStrategic Missile Troops are the only operator of the UR-100N. As of May 2025,[15][16][17] 12Avangard-equippedUR-100N UTTHs are deployed with:
After theBudapest Memorandum was signed in 1994, the43rd Rocket Army shipped more than 1,326 warheads from its nuclear storage depots: 675 warheads in 1994, 477 in 1995 and 174 in 1996. On May 31, 1996, the final train left Ukraine for Russia laden with the last ofapproximately 1,800 warheads, including more than 400weapons from the46th Bomber Army."[citation needed]
{{cite book}}: CS1 maint: publisher location (link)