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UR-100N / SS-19 STILLETO

Once regarded by some as the "backbone" of the Soviet ICBM force, the fourth generation UR-100N / SS-19 intercontinental ballistic missile is a two-stage, tandem, storable liquid-propellant missile. The SS-19 is approxiamately 80 feet long and 8 1/2 feet in diameter. It was a competing design with the SS-17 Spanker, though in fact both were deployed to partially replace the SS-11 force.

The UR-100N is similar to the UR-100, but with an increased diameter and longer propellant tanks its launch weight was more than doubled and the throw-weight was increased over three-fold. The UR-100N uses asymmetrical dimethylhidrazine and nitrogen tetraoxide propellants. The first stage consists of four autonomous closed-cycle single-chambered rocket motors. The second stage has a closed-cycle single chambered sustainer and a four chambered open cycle control motor with four rotating nozzles. The guidance and control system of the SS-19 is identical to that of the SS-18, and permits remote monitoring of missile status while on alert, as well as automatic pre-launch preparation, remote missile targeting before launch and in-flight control of the missile via a flexible pitch control program. The UR-100N silos were constructed at the same sites as the UR-100U silos but were completely dismantled and rebuilt to increase the survivability of the new missiles. The UR-100N was launched in the hot mode through the thrust of the first stage sustainer engine.

The SS-19 has been deployed in three configurations.

• SS-19 Mod-1 - Through the increase of throw-weight and reduction of the size of the warheads relative to the UR-100 the UR-100N carries six MIRV warheads with a yield of 550 KT each according to Russian sources [Western estimates suggested a yield of one- to two-megatons]. According to Western estimates the booster alone was limited to a range of 4900 nm but the total system, booster plus PBV, was assessed as being capable of delivering all six RVs to a maximum range of 5200 nm. Development was approved on 19 August 1970 and developed by V. N. Chelomey. The flight tests of the UR-100N were conducted at the Baikonur cosmodrome from 09 April 1973 through October 1975. The missile was initially deployed on 30 December 1975, though according to Western estimates it achieved an initial operational capability in 1974. The first regiment with UR-100N missiles was put on alert on 26 April 1975 and by the end of 1975 a total of 60 launchers were deployed. The missile employed an inertial guidance system that was is estimated by some Western sources to have an operational CEP of 0.3 nm in 1975 with a potential CEP of 0.25 nm by 1980. However, due to the hasty deployment of the UR-100N a major design flaw was overlooked. Training launches that took place after its deployment revealed a significant reduction of accuracy due to resonant oscillations of the missile. Subsequently all deployed missiles were modified to eliminate the problems.

• SS-19 Mod-2 - Otherwise similar to the Mod-1, this variant carries a single warhead with a yield reported by Russian sources of between 2.5 and 5 MT. Between 1976 and 1978 the UR-100N reached its maximum operational inventory of 180 missiles, of which 60 carried a single warhead. Both of these SS-19 Mods were attributed "hard target kill" capabilities by the West.

• SS-19 Mod-3 -The development of an improved version was authorized on 16 August 1976. The upgrades to the missile involved the development of improved engines and modification of the command system. The extent of protection from a nuclear strike at their silos was considerably improved. The flight-design tests of the improved version that received the designation UR-100NUTTH were conducted between 26 June 1979 and 26 October 1979. Its deployment began on 05 November 1979.

The first regiment with the UR-100NUTTH was put on alert on 06 November 1979. Between 1980-1982 UR-100N missiles with a single warhead (SS-19 Mod 2) were replaced by the UR-100NUTTH (SS-19 Mod 3). The replacement of all UR-100N missiles was completed in 1983. In 1984 the UR-100NUTTH reached its maximum operational inventory of 360 missiles. From 1987 on they were gradually replaced by new missiles. The silo-based version of the SS-24 replaced some SS-19s.

When the START-1 treaty was signed in 1991 the Soviet Union had a total of 300 UR-100NUTTH missile stationed in Russia and Ukraine. After the dissolution of the Soviet Union Ukraine claimed ownersip of the missiles located on its territory. In compliance with the START treaty provisions Ukraine is in charge of the dismantling the launchers for the SS-19 missiles. However, all nuclear warheads that were deployed in Ukraine were dismantled by Russia.

Some 170 launchers remain in Russian territory, of which 10 were deactivated but not dismantled. In December 1995 Strategic Rocket Forces Commander Colonel General Igor Sergeyev announced a policy under which the service life of the SS-19 would be extended from 10 years to 25 years. The missiles will remain on alert at least through 2005, and the missiles that were deployed in the early 1980s will serve beoynd this.

Following the ratification of the START-II treaty by the Duma, Russia is obliged to dismantle all ground-based ICBMs with multiple warheads. Under the treaty provisions a total of 105 of the UR-100NUTTH missiles can be retained provided they are downloaded to carry only one warhead instead of six.

Specifications
	Mod-1	Mod-2	Mod-3
DIA	SS-19	SS-19	SS-19
NATO	Stiletto	Stiletto	Stiletto
Bilateral	RS-18A	RS-18A UTTKh	RS-18B
Service	UR-100N	UR-100N	UR-100NU
OKB/Industry	15A30	15A30	15A35
Design Bureau	OKB-52, KB Salyut, Acad. V. N. Chelomey	OKB-52, KB Salyut, Acad. V. N. Chelomey	OKB-52, KB Salyut, Acad. V. N. Chelomey
Approved	8/19/1970	8/19/1970	8/16/1976
Years of R&D	1964-73	1964-1973
Engineering and Testing	1973-75	1973-75	1977-79
First Flight Test	9/15/1972 failure & 12/28/1973 success	4/9/1973	10/26/1977
IOC	4/26/1975	1975	1979
Deployment Date	12/301975	12/30/1975	11/5/1979
Type of Warhead	MIRV	Single	MIRV
Warheads	6	1	6
Yield per Warhead (Mt)	0.5  0.55 0.750	2.5 - 5.0	0.5-0.75
Payload (t)	4.350	4.350	4.350
Total length (m)	24.0	24.0	24.3
Total length w/o Warhead (m)	21.1	21.1	21.1
Missile Diameter (m)	2.50	2.50	2.50
Launch Weight (t)	103 - 105.6	105.6	103.4 - 105.6
Fuel Weight (t)	93.1	93.1	93.1
Range (km)	9,650	10,000	10,000
CEP (m) (Russian Sources)	?	?	920
CEP (m) (Western Sources)	350-550	250-400	220-380

Number of Stages	2
Canister length (m)	19.4
Canister length w/o front meters (m)
Canister diameter (m)	2.9
Booster guidance system	Inertial

	1st stage	2nd stage	3rd. Stage
Length (m)	17.2	2.8
Body diameter (m)	2.5	2.5	2.5
Fueled weight (t)	86.3	86.3
Dry weight (t)
Engine Designation	RD-0233 / RD-0234	RD-0235 (14/15D113)	N/A
Vernier Engine Designation	N/A	RD-0236 (15D114)	N/A
Bus Engine Designation Third Stage	N/A	N/A	RD-0237
Design Bureau Main Engines	OKB-154, Acad. S. A. Kosberg	OKB-154, Acad. S. A. Kosberg	N/A
Design Bureau Vernier Engine	N/A	OKB-154, Acad. S. A. Kosberg	N/A
Design Bureau Bus Engine Third Stage	N/A	N/A	OKB-154, Acad. S. A. Kosberg
Configuration	Cluster of four engines	One engine	N/A
Configuration Vernier Engine	N/A	Four vernier chambers	N/A
Configuration Bus engine Third Stage	N/A	N/A	Four chambers
Years of R & D	1969 1974	1969 - 1974	N/A
Years of R & D Vernier Engine	N/A	1969 - 1974	N/A
Years of R & D Bus Engine Third Stage	N/A	N/A	1969 - 1974
Propellants	Liquid	Liquid	Liquid
Fuel	UHMH	UDMH	UDMH
Oxidizer	Nitrogen Tetroxide	Nitrogen Tetroxide	Nitrogen Tetroxide
Burning time (sec.)
Main Engine Thrust Sea Level/Vacuum (Tonnes)	46.961/52.958 - 53.1	24.5 Vacuum	N/A
Verniers Thrust Sea Level/Vacuum (Tonnes)	N/A	1.6 Vacuum	N/A
Third Stage Bus Engine Thrust Vacuum (Tonnes)	N/A	N/A	0.5 Vacuum
Total Thrust Sea Level/Vacuum (Tonnes)	187.8442/207.8319	30.9 Vacuum	2.0 Vacuum
Main Engine Specific Impulse Sea Level/ Vacuum (sec.)	291 / 310	320 Vacuum	N/A
Vernier Engine Specific Impulse Sea Level/Vacuum (sec.)	N/A	293 Vacuum	N/A
Bus Third Stage Engine Specific Impulse Vacuum (sec.)	N/A	N/A	?

Basing Mode	Silo
Hardness
Launching Technique	Hot
Deployed boosters
Test Boosters
Warheads Deployed
Training Launchers
Space Booster Variant	Yes  SL-X- ? , Rockot

Deployment Sites

START	Locale US-Designation
Khmel?Nitskiy	Derazhnaya
Kozel?sk	Kozelsk
Pervomaysk	Permovaysk
Tatishchevo	Tatishchevo

SS-19/RS-18  in Launch Canister

SS-19/RS-18 Missile

SS-19/RS-18 Stage 1

 

SS-17/RS-16 and SS-19/RS-18 Emplacement Equipment

Sources and Resources

• Russian Strategic Nuclear Weapons, Pavel Podvig, ed., IzdAT, Moscow, 1998, 492 pp. (in Russian). Authors: Oleg Bukharin, Timur Kadyshev, Eugene Miasnikov, Pavel Podvig, Igor Sutiagin, Maxim Tarasenko, Boris Zhelesov
• UR-100N @ Encyclopedia Astronautica by Mark Wade
• SS-19 Stiletto @ US Naval Institute Military Database
• "A History of Strategic Arms Competition 1945-1972" (U), Volume 3, A Handbook Of Selected Soviet Weapon and Space Systems, United States Air Force, June 1976. pgs 256 and 260
• Soviet Military Power 1989. The Defense Intelligence Agency. 1989
• The SALT Handbook edited by Michael B. Donley