View source for R-39 (missile)

{{short description|Submarine-launched ballistic missile}}
{{Infobox weapon
|is_missile=yes
|name = R-39
|image = Rsm52.jpg
|caption = R-39
|origin=Soviet Union
|type = [[Submarine-launched ballistic missile|SLBM]]
|vehicle_range = {{Convert|8300|km|mi}}<ref name=MT.com/>
|filling = 10 MIRV thermonuclear<ref name=MT.com>{{cite web |url=http://www.missilethreat.com/missilesoftheworld/id.155/missile_detail.asp |title=SS-N-20 |access-date=2012-01-31 |url-status=dead |archive-url=https://web.archive.org/web/20120202043352/http://missilethreat.com/missilesoftheworld/id.155/missile_detail.asp |archive-date=2012-02-02 }}</ref>
|yield = 100–200&nbsp;kt each<ref name=MT.com/>
|engine = Three-stage [[Solid-fuel rocket]]<ref name=MT.com/>
|guidance = [[Astro-inertial guidance]]<ref name=FAS>{{cite web|url=https://fas.org/nuke/guide/russia/slbm/r39.htm |title=R-39 / SS-N-20 Sturgeon SLBM - Russian / Soviet Nuclear Forces |publisher=Fas.org |date=2000-07-13 |access-date=2018-08-22}}</ref>
|accuracy = {{Convert|500|m|ft}} [[circular error probable|CEP]]<ref name=FAS/>
|speed = 
|length = {{Convert|16.1|m|ft}}<ref name=MT.com/> ({{Convert|8.4|m|ft}} without warhead)
|diameter = {{Convert|2.4|m|ft}}<ref name=MT.com/>
|weight = {{Convert|84|t|lb}}
|payload_capacity = {{Convert|2,550|kg|lb}}<ref name=FAS/>
|designer=[[Makeyev Rocket Design Bureau]]
|manufacturer =[[Zlatoust Machine-Building Plant]]
|unit_cost =
|service= 1983–2004
|used_by = [[Soviet Navy]]<br/>[[Russian Navy]]
}}
[[File:SLBM Comparison.jpg|350px|thumb|Submarine-based missiles: R-29, R-29R, R-39, R-29RМ, CSS-NX-3, JL-2]]

The '''R-39''' ({{Langx|ru|Р-39||}}; [[NATO reporting name]]: '''SS-N-20 ''[[Sturgeon]]'''''; bilateral arms control designation: '''RSM-52''') was a [[submarine-launched ballistic missile]] (SLBM) that served with the [[Soviet Navy]] from its introduction in 1983 until 1991, after which it served with the [[Russian Navy]] until 2004. The missile had [[GRAU]] indices of 3M65, 3M20, and 3R65. It was carried on board [[Typhoon-class submarine]]s.

An intercontinental missile, the R-39 had a three-stage solid-fuel boost design with a liquid-fuel post-boost unit carrying up to ten [[multiple independently targetable reentry vehicle]] warheads.  Like other SLBMs the initial launch was powered by a gas generator in the bottom of the firing tube.  During the missile's passage through the water additional motors produce a gaseous wall around the missile, reducing hydrodynamic resistance.{{citation needed|date=July 2012}}  The launch system was designated "D-19".

==Development==
Development work began at [[Makeyev Rocket Design Bureau|NII Mashinostroyeniya]] in 1971 and the design gained official approval in 1973. Initial test flights from 1979 found problems in the solid-fuel boost engines, over half of the early flights failed. Later tests aboard a modified [[Typhoon-class submarine]] were more successful and deployment began in May 1983, with 20 missiles in each submarine. At full deployment, 120 missiles were deployed with 1,200 total warheads.

Under the terms of the [[START I]] and [[START II]] treaties, from 1996 a number of R-39 missiles were destroyed. Throughout the 1990s, Typhoon class submarines and the R-39 missiles they carried were gradually withdrawn from service. All the missiles were decommissioned by 2004 and all the Typhoon class submarines have been retired, except for one which is used as a test platform for the [[RSM-56 Bulava]].

A successor design, [[R-39M]] Grom ({{langx|ru|Гром}}, Thunder)/RSM-52V/SS-N-28 for D-19UTTKh launch system, suffered a succession of testing failures and was cancelled.

==Operators==
===Former operators===
; {{RUS}}
* [[Russian Navy]]
; {{USSR}}
* [[Soviet Navy]]

==See also==
* {{lwc|R-39M}}
* {{lwc|R-29 (missile)|R-29}}
* {{lwc|R-29RM (missile)|R-29RM}}
* {{lwc|R-29RMU Sineva}}
* {{lwc|R-29RMU2 Lajner}}
* {{lwc|RSM-56 Bulava}}
* {{lwc|UGM-133 Trident II}}
* {{lwc|M45 (missile)|M45}}
* {{lwc|M51 (missile)|M45}}
* {{lwc|JL-2}}
* {{lwc|K-6 (missile)|K-6}}
* {{lwc|Pukguksong-5}}

==References==
{{Reflist}}

==External links==
*[http://thebulletin.metapress.com/content/t308307173860748/?p=2114f00338444b71903d97f57d88c181&pi=2 Russian nuclear forces 2005], [http://thebulletin.org The Bulletin of the Atomic Scientists], March/April 2005.

{{Russian and Soviet military designation sequences}}
{{Russian and Soviet missiles|SSM}}
{{USAF/DoD reporting names}}

{{DEFAULTSORT:R-039}}
[[Category:Submarine-launched ballistic missiles of the Soviet Union]]
[[Category:Makeyev Rocket Design Bureau]]
[[Category:Military equipment introduced in the 1980s]]