United States LGM-118 Peacekeeper

LGM-118 Peacekeeper (Jane's Strategic Weapon Systems)
Originated From:United States
Possessed By:United States
Basing:Silo-based
Length:21.8 m
Diameter:2.34 m
Launch Weight:87,750 kg
Payload:10 Mk 21 RVs on MIRV platform
Warhead:W87 nuclear, 300-475 kT each
Propulsion:Three-stage solid propellant
Range:9,600 km
Status:Terminated
In Service:1986-2005

LGM-118 Peacekeeper is an intercontinental-range, silo-based, solid propellant ballistic missile. The program began as the MX system in the late 1970s as a way to increase the US counterstrike capabilities against the Soviet Union, which was focusing on hardened shelters and a highly capable missile defense. The MX was designed with an advanced guidance system and a large number of warheads. It was the first US surface missile to use a cold-launch system, meaning it is ejected from the silo before the engine ignites. Like the Minuteman III, the Peacekeeper is technically a four-stage missile, due to propulsion on the Post-Boost Vehicle (PBV), but it is not referred to as such because of treaty restrictions.

The Peacekeeper is the most advanced strategic asset developed by the United States. The system easily has the range to reach its primary targets in Russia and the Peoples Republic of China (PRC). With its Multiple Independent Reentry Vehicle (MIRV) warheads, powerful payload, extremely high accuracy, and modern penetration aids, the Peacekeeper is highly effective against multiple hardened targets, which is its main function. The original 50 Peacekeeper missiles could theoretically destroy as many as 500 Soviet missile silos. However, the Soviet deployment of road mobile systems, missile submarines, and early warning radars would render such an attack futile. For this reason, it is likely that the Peacekeeper missiles were targeted at Soviet cities, in keeping with the official US doctrine of deterrence.

The Peacekeeper was deployed in Minuteman missile silos, although the program originally planned to deploy another 50 missiles aboard railcar launch vehicles. The missile can be launched within several minutes of a nuclear strike, has emergency airborne launch controllers, and is protected from nuclear strikes with its hardened silo and shock-protected launch canister. In the worst case scenario of counterstrike against US nuclear weapons, a small number of Peacekeeper missiles could do a tremendous amount of damage to an enemy nation, greatly increasing the risk of a first strike and improving the US policy of deterrence. Its high reliability and survivability makes it extremely effective as a counterstrike weapon. Its cold-launch system allows for a sustained nuclear conflict, as silos could be refurbished and reloaded with another missile.

The Peacekeeper has a range of 9,600 km (5,965 miles) while carrying 10 MIRV warheads. It has the capability to carry 12, but Strategic Arms Reduction Treaty (START I) restrictions prevent the number of warheads from exceeding 10. Each warhead uses an Mk 21 RV and has a 300-475 kT yield W87 nuclear warhead. The system is equipped with a highly advanced inertial navigation system that provides an accuracy of 90 m CEP for each warhead. The missile is highly compact for its capabilities, with a length of 21.8 m, a width of 2.34 m and a launch weight of 87,750 kg. It has a three-stage solid propellant design.

The LGM-118 Peacekeeper missile started in 1972 with a demand for a new ICBM which was to be designed around the concept of a large number of warheads coupled with silo-killing capabilities. The full-scale development of the Peacekeeper began in 1979 with the first flight test occurring in 1983. The number of missiles planned to be deployed in silos was reduced from 100 to 50 in 1984. Another 50 were planned to be deployed in railcar launchers, but this was cancelled in 1991. The missile was first deployed in 1986 at the F. E. Warren Air Force Base in Wyoming in modified Minuteman silos. A total of 114 missiles were produced by the end of 1988. In 2002 it was declared that the Peacekeeper would be phased out of service from October 2002 to December 2005.

The removal of the Peacekeeper missile, one of the most advanced ballistic missile systems in the world, was primarily due to financial considerations. The switchover to entirely Minuteman III missiles significantly decreased the cost of maintaining our missile force, though it comes at the detriment of our nuclear force. 1

  1. Lennox, Duncan. “LGM-118 Peacekeeper.” Jane’s Strategic Weapon Systems (Offensive Weapons). October 13, 2011. (accessed September 12, 2012).
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