| Country: |
Russian Federation |
| Alternate Name: |
Satan, RS-20A |
| Class: |
ICBM |
| Basing: |
Silo based |
| Length: |
33.65 m |
| Diameter: |
3.00 m |
| Launch Weight: |
210,400 kg |
| Payload: |
4 or 10 MIRV |
| Warhead: |
4x1 MT or 10x400 kT nuclear |
| Propulsion: |
2-stage liquid |
| Range: |
10200 km |
| Status: |
Terminated |
| In Service: |
1975-1994 |
Details
Russian Designation: RS-20A
The SS-18 is an intercontinental-range, silo-based, liquid propellant ballistic missile deployed by the Soviet Union. It is the largest of the fourth generation Soviet intercontinental-range missile and the only ‘heavy’ missile allowed under the second Strategic Arms Limitation Treaty (SALT II). A total of six versions are known to exist. The SS-18 was extremely similar in design to its predecessor, the SS-9.
The SS-18 Mod 1 was an extremely powerful strategic weapon. It carried Multiple Independent Reentry Vehicle (MIRV) warheads, each with a nuclear yield greater than that of many contemporary missiles. It had range such that all major targets within the continental United States could be attacked. Like the SS-9, the SS-18 Mod 1 compensated for its lack of accuracy by using a powerful warhead that could have made it suitable for the destruction of the missile silos. Though the warhead was neither large nor accurate enough to guarantee the destruction of a hardened silo, the probability of success was reasonable. This was especially true if the target was a group of missiles and multiple warheads were used. This gave the Soviet Union the capability to devastate US missile forces, though this would require the missiles to land before US missiles could be launched. One missile would also be able to destroy multiple population centers, making the SS-18 Mod 1 effective as a counter-value weapon as well. The SS-18 Mod 1 and Mod 2 had the exact same missile design; the only difference being the warhead. The SS-18 Mod 1 could deploy its MIRV warheads up to a range of 10,200 km (6,338 miles). The Mod 1 version employed either 4 MIRV, each carrying a 1 MT nuclear warhead, or 10 MIRV, each carrying a 400 kT nuclear warhead. The missile used an inertial navigation system with digital computer guidance and control. The accuracy of the system is not known, but due to the constraints of the MIRV technology of the time, it was likely in the area of 1,600 m CEP. The missile was a massive 210,000 kg, with a length of 33.65 m and a 3.0 m diameter. The missile used a two-stage liquid propellant engine.
The SS-18 entered development in 1969 as a replacement for the SS-9 missile. It was essentially a redesigned, modernized SS-9. The flight tests started in 1973 and the Mod 1 version of the missile was first deployed operationally in 1975 within converted SS-9 missile silos and launch complexes. The SS-18 Mod 2 entered service in 1978, with the Mod 3 and Mod 4 entering service in 1980 and the Mod 5 and Mod 6 entering service in 1988. By 1991, there were 308 SS-18 missiles in silos grouped among six major launch sites.
The first Strategic Arms Reduction Treaty (START I) required the number of SS-18 missiles to be reduced to 154 by 2003. As a result, the early versions of the SS-18 were removed from service to maintain the more advanced models; all Mod 1 missiles were removed by 1994 while the Mod 2 missiles were removed by 2001. The requirement of the START I has been fulfilled, as only 145 SS-18 missiles remained in service by the end of 2002. This was accomplished by destroying or converting the missiles into satellite launch vehicles.(1)
Footnotes
- Jane’s Strategic Weapons Systems, Issue 50, ed. Duncan Lennox, (Surrey: Jane’s Information Group, January 2009), 167-69.
