UR-100N

Development of the UR-100N began at OKB-52 in 1970 and flight tests were carried out from 1973 through 1975. In 1976, the improved UR-100NUTTKh (SS-19 Mod 3) version entered development with flight tests in the later half of the decade. The rocket's control system was developed at NPO "Electropribor"[6] (Kharkiv, Ukraine).

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.

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 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. As of 2018, the Strategic Missile Troops had 20 (or more likely just 10) SS-19s in active service.[8] Recent political developments have led to rearmament of the missiles with the Avangard hypersonic glide vehicles (HGVs), with the HGV-carrying version of the missile having SS-19 Mod 4 designation.[9][1] On 27 December 2019, the first missile regiment armed with the Avangard HGV officially entered combat duty.[10]

The units previously held by Ukraine have been returned to Russia or decommissioned.

US Air Force National 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 the Rokot space launch system, which was used in several successful launches in the 1990s and early 2000s (decade), 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.

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 SS-19 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 SS-19 missiles in compliance with the START 1 treaty. Nuclear warheads that were deployed in Ukraine were also dismantled following terms of the treaty.[14]

 Russia

The Strategic Missile Troops are the only operator of the UR-100N. As of March 2020,[15] 2 silo-based SS-19 Mod 4 missiles are deployed with:

• 13th Red Banner Rocket Division at Yasny, Orenburg Oblast

• Strategic Missile Troops
• RS-24 Yars
• RS-26 Rubezh
• RS-28 Sarmat
• R-36 (missile)
• RT-2PM Topol
• RT-2PM2 Topol-M
• LGM-30 Minuteman
• DF-5
• DF-41

• CSIS Missile Threat - SS-19 "Stiletto
• Russian Military Analysis