{{Infobox weapon |is_missile=yes |name = UR-100N<br /><small>SS-19 Stiletto</small> | image = SS-19 missiles.jpg | image_size = 300 |type = ICBM |vehicle_range ={{convert|10,600|km}} |filling = 1 x 1 Mt or 6 x 400 kt<ref name="FAS_report">{{cite journal|url=http://bos.sagepub.com/content/early/2015/04/13/0096340215581363.full.pdf+html|title=SAGE Journals: Your gateway to world-class journal research|journal=Bulletin of the Atomic Scientists|date=January 2015|volume=71|issue=3|pages=84–97|doi=10.1177/0096340215581363|last1=Kristensen|first1=Hans M.|last2=Norris|first2=Robert S.|s2cid=145329451|doi-access=free}}</ref> |engine = two-stage liquid fuel #First stage powered by three RD-0233 and one RD-0234<ref name=kbkha-rd0233 /><ref name=rsw-ur100n /> #Second stage powered by a RD-0235 main engine one RD-0236 vernier engine<ref name=kbkha-rd0233 /><ref name=rsw-ur100n /> #MIRV Service block use the RD-0237 as steering engine<ref name=ea-rd0237 /> |guidance = inertial |accuracy= CEP 300&nbsp;m |speed ={{convert|7.64|km/s|abbr=on}} |length = {{convert|27.5|m|ftin|abbr=on}} |diameter ={{convert|2.48|m|ftin|abbr=on}} |weight ={{convert|126.3|t|lbs|abbr=on}} |payload_capacity = 4,950&nbsp;kg |designer=NPO Mashinostroyeniya |manufacturer = Khrunichev Machine-Building Plant |unit_cost = |service = 1975&ndash;present |used_by = Russian Strategic Missile Troops }}

The '''UR-100N''' ({{langx|ru|УР-100Н}}), also known as '''RS-18A''', is an intercontinental ballistic missile in service with Soviet and Russian Strategic Missile Troops. The missile was given the NATO reporting name '''SS-19 Stiletto''' and carries the industry designation '''15A30'''.<ref>{{Cite web|url=https://missilethreat.csis.org/missile/ss-19/|title=UR-100 (SS-19)|website=Missile Threat}}</ref>

==Development== 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''' (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 at NPO "Electropribor"<ref>{{cite web|url=http://web.mit.edu/slava/space/essays/essay-krivonosov.htm|title=Krivonosov, Khartron: Computers for rocket guidance systems|website=web.mit.edu}}</ref> (Kharkiv, Ukraine).

==Description== The UR-100N is a fourth-generation silo-launched liquid-propellant ICBM similar to the UR-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.<ref>{{cite web |url=http://inbsite.com/missiles1.html |title=Russian Ballistic Missiles, баллистические ракеты России |access-date=2015-09-14 |url-status=dead |archive-url=https://web.archive.org/web/20130331080952/http://inbsite.com/missiles1.html |archive-date=31 March 2013 |df=dmy-all }}</ref>

==Operational history== 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 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) UR-100NUTTKh in active service.<ref>{{cite journal|title=Russian nuclear forces, 2018|first1=Hans M.|last1=Kristensen|first2=Robert S.|last2=Norris|date=30 April 2018|journal=Bulletin of the Atomic Scientists|volume=74|issue=3|pages=185–195|doi=10.1080/00963402.2018.1462912|bibcode=2018BuAtS..74c.185K|doi-access=free}}</ref> Recent political developments have led to rearmament of the missiles with the ''Avangard'' hypersonic glide vehicles (HGVs) (NATO designation '''SS-19 Mod 4''')<ref>{{cite web|url=http://armyrecognition.com/march_2018_global_defense_security_army_news_industry/russia_launched_serial_production_of_avangard_hypersonic_missile.html|title=Russia launched serial production of Avangard hypersonic missile - March 2018 Global Defense Security army news industry - Defense Security global news industry army 2018 - Archive News year|last=xavier|website=armyrecognition.com}}</ref><ref name="FAS_report"/> On 27 December 2019, the first missile regiment armed with the ''Avangard'' HGV officially entered combat duty.<ref name= "tass_combat_duty">{{cite news|url= https://tass.ru/armiya-i-opk/7436431 |script-title=ru:Первый ракетный полк "Авангарда" заступил на боевое дежурство |trans-title=The first Avangard missile regiment took up combat duty |website= TASS |date= 27 December 2019 |access-date= 27 December 2019|language= ru}}</ref>

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.<ref>{{cite web |title=Ballistic and Cruise Missile Threat |url=https://www.nasic.af.mil/LinkClick.aspx?fileticket=F2VLcKSmCTE%3d&portalid=19 |year=2017 |publisher=Defense Intelligence Ballistic Missile Analysis Committee}}</ref>

==Civil application== 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, and one failed launch of the ESA CryoSat 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.

==START I treaty== 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.<ref>{{Cite book |title=Europe undivided: the new logic of peace in U.S.-Russian relations |last=Goodby |first=James |publisher=United States Institute of Peace Press |year=1998 |location=Washington D.C. |pages=81}}</ref> The Soviet Union had 300 100NUTTH missiles stationed in both Russia and Ukraine: 130 deployed in Ukraine, and the rest scattered around Russia.<ref>{{Cite web |url=http://www.globalsecurity.org/wmd/world/russia/ur-100n.htm |title=UR-100N / SS-19 STILLETO |last=Pike |first=John |website=GlobalSecurity.org |access-date=2017-04-27}}</ref> 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 the START&nbsp;I treaty. Nuclear warheads that were deployed in Ukraine were also dismantled following terms of the treaty.<ref>{{Cite book |title=Russian Strategic Nuclear Forces |last=Podvig |first=Pavel |url=https://books.google.com/books?id=CPRVbYDc-7kC |publisher=MIT |year=2004 |pages=223 |isbn=9780262661812 }}</ref>

==Operators== ; {{RUS}}: The Strategic Missile Troops are the only operator of the UR-100N. As of May 2025,<ref>{{cite web|url=http://russianforces.org/missiles/|title=Strategic Rocket Forces|publisher=russianforces.org|access-date=7 January 2020}}<br>{{Cite web|url=https://armstrade.org/includes/periodics/news/2020/1222/133060997/detail.shtml|title=ЦАМТО / Новости / РВСН получили на вооружение четыре ракетных комплекса "Авангард"}}<br>{{cite web | url=https://tass.com/defense/1378715 | title=Russian nuclear trifecta modernization level highest in history, defense minister says }}<br>{{cite web | url=https://tass.com/defense/1539059 | title=Missile regiment near Orenburg being rearmed with Avangard system — Defense Ministry }}<br>{{cite web | url=https://tass.com/defense/1551935 | title=Avangard missiles put on combat duty in Russia's southern Urals }}</ref><ref>{{cite web | title=ЦАМТО / / В Оренбургской области завершены работы по перевооружению очередного полка соединения РВСН на РК «Авангард» | website=ЦАМТО / Центр анализа мировой торговли оружием | date=2023-12-18 | url=https://armstrade.org/includes/periodics/news/2023/1218/073577021/detail.shtml | language=ru | ref={{sfnref | ЦАМТО / Центр анализа мировой торговли оружием | 2023}} | access-date=2025-05-30}}</ref><ref>{{cite journal | last=Podvig | first=Pavel | title=New Avangard positions at Dombarovskiy | journal=Russian Strategic Nuclear Forces | date=2025-05-28 | url=https://russianforces.org/blog/2025/05/new_avangard_positions_at_domb.shtml | access-date=2025-05-30}}</ref> 12 Avangard-equipped UR-100N UTTHs are deployed with: * 13th Red Banner Rocket Division at Yasny, Orenburg Oblast

===Former operators=== ; {{USSR}} ; {{UKR}}: * The Armed Forces of Ukraine inherited a number of missiles from the Soviet Union and turned them over to Russia.<ref>{{cite book |last1=Podvig |first1=Pavel |title=Russian Strategic Nuclear Forces |date=2001 |publisher=Cambridge: The MIT Press |isbn=9780262661812 |pages=220–223 |edition=}}</ref>

After the Budapest Memorandum was signed in 1994, the 43rd 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 of approximately 1,800 warheads, including more than 400 weapons from the 46th Bomber Army."{{cn|date=January 2025}}

==See also== * 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 * Agni-V * DF-5 * DF-41

==References== <references> <ref name=kbkha-rd0233>{{cite web |url=http://www.kbkha.ru/?p=8&cat=10&prod=47 |title= RD-0233, RD-0234, RD-0235, RD-0236, RD-0237. Intercontinental ballistic missiles RS-18 |publisher=KBKhA |access-date=2015-06-19}}</ref> <ref name=ea-rd0237>{{cite web |url=http://www.astronautix.com/engines/rd0237.htm |title=RD-0237 |website=Encyclopedia Astronautica |access-date=2015-06-19 |url-status=dead |archive-url=https://web.archive.org/web/20150824113726/http://www.astronautix.com/engines/rd0237.htm |archive-date=24 August 2015 |df=dmy-all }}</ref> <ref name=rsw-ur100n>{{cite web |url=http://www.russianspaceweb.com/ur100n.html |title=UR-100N Family |last=Zak |first=Anatoly |website=RussianSpaceWeb.com |access-date=2015-06-19}}</ref> </references>

==External links== * [http://missilethreat.csis.org/missile/ss-19/ CSIS Missile Threat - SS-19 "Stiletto] * [http://warfare.be/?catid=265&linkid=2310 Russian Military Analysis]

{{Universal Rocket}} {{Russian and Soviet military designation sequences}} {{Russian and Soviet missiles|SSM}} {{Use dmy dates|date=June 2017}}

Category:1974 in spaceflight Category:Cold War intercontinental ballistic missiles of the Soviet Union Category:Universal Rocket (rocket family) Category:Intercontinental ballistic missiles of the Soviet Union Category:NPO Mashinostroyeniya products Category:Military equipment introduced in the 1970s