LGM-118A Peacekeeper

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LGM-118A Peacekeeper

Test launch of a Peacekeeper ICBM by the 1st Strategic Aerospace Division (1 STRAD), Vandenberg AFB, CA (USAF)
Type Intercontinental ballistic missile
Service history
In service 1986
Production history
Manufacturer Boeing, Martin Marietta, TRW and Denver Aerospace
Unit cost $70 million
Specifications
Weight 96.75 tons
Length 71 ft 6 in (21.8 m)
Diameter 7 ft 7 in (2.3 m)

Warhead up to 10 Avco Mk-21 re-entry vehicles each carrying a 300KT (1.25 PJ) W87 warhead.
Detonation
mechanism
Airburst

Engine * First Stage: 500,000 lbf (2.2 MN thrust) Thiokol SR118 solid fuel motor;
Operational
range
9700 km
Guidance
system
Inertial (AIRS), 393 ft 7 in (120 m) CEP
Launch
platform
Fixed silo

The LGM-118A Peacekeeper, initially known as the "MX missile", was a land-based ICBM deployed by the United States starting in 1986. A total of 50 missiles were deployed. Under the START II treaty, which never entered into force, the missiles were to be removed from the U.S. nuclear arsenal in 2005, leaving the LGM-30 Minuteman as the only type of land-based ICBM in the U.S. arsenal. In spite of the demise of START II, the last of the LGM-118A "Peacekeeper" ICBMs were decommissioned on September 19, 2005.

The Peacekeeper was a MIRVed missile; each rocket could carry up to 10 re-entry vehicles, each armed with a 300-kiloton W87 warhead/MK-21 RVs (twenty times the power of the bomb dropped on Hiroshima during World War II)[1].

Contents

[edit] Development and deployment

During the late 1970s, the Soviet Union fielded a large number of heavy, increasingly accurate, MIRVed ICBMs (like the SS-18) which seriously threatened the survival of Minuteman III missiles in their silos. If the Soviet Union could have knocked out the majority of these missiles and the strategic bombers on ground, it would have left the United States with no counterforce capability for the second strike. The Poseidon and Trident I SLBMs were not accurate enough for counterforce strikes. If the Soviet first strike would have avoided hitting civil targets, the US might have been forced not to retaliate against Soviet cities, because of similar Soviet countercity capabilities. So the United States needed weapons which could survive a Soviet first-strike and neutralize the remaining Soviet strategic arsenal, in order to avoid the nuclear blackmail.

The development of the Peacekeeper began with the intent of its being a counterforce, hard-target weapon. It was to be aimed at hardened enemy missile silos with first-strike capability. This required high accuracy, survivability, range and a flexibility that was not available in the Minuteman III.

Accuracy was an especially important issue, since the effects of the blast and heat from a thermonuclear detonation decrease very rapidly with distance from the impact point. The targets were hardened Soviet ICBM-silos, especially those housing the heavy SS-18, which were targeted at Minuteman missile silos.

Design work began on the MX (Missile-eXperimental) in 1972.

In 1976, Congress refused to fund a silo-based system on grounds of vulnerability and the project was halted until 1979 when President Carter authorized development of a system of multiple protective shelters linked by road. President Reagan canceled the new shelter system in 1981 and pushed for a "dense pack" solution to speed deployment. This "dense pack" idea involved building super-hardened silos that would withstand more than 10,000 psi (70 MPa) of overpressure and spacing them only 1,800 feet (550 m) apart. The reasoning behind this idea was that a nearby nuclear explosion would damage other incoming warheads in the same wave of attack and would allow a substantial portion of the missiles to survive. This "fratricide theory" was fundamentally flawed due to the relative ease with which the Soviets could modify their warheads and circumvent this design. Congress again rejected the silo-based system.

A compromise was developed in mid-1983, by which there would be swift deployment of 100 new missiles in existing Minuteman silos to show "national will", the removal of the venerable Titan II ICBM from use, and the later introduction of a new more mobile single-warhead ICBM.

Technicians secure a number of Mk-21 re-entry vehicles on a Peacekeeper MIRV bus.
Technicians secure a number of Mk-21 re-entry vehicles on a Peacekeeper MIRV bus.

The missile was officially designated the LGM-118A Peacekeeper. It was first test fired on June 17, 1983, from Vandenberg AFB, California, traveling 4,200 nautical miles (7,800 km) to impact successfully in the Kwajalein Test Range in the Pacific. The operational missile was first manufactured in February 1984 and deployed in December 1986 to the Strategic Air Command, 90th Strategic Missile Wing at F.E. Warren AFB in Wyoming into retro-fitted Minuteman silos. Fifty working missiles had been deployed at Warren by December 1988. The planned deployment of one hundred missiles was canceled by Congress in July 1985, again over the survivability problem. In that decision, Congress limited the deployment of Peacekeeper ICBMs to 50 missiles until a more survivable basing plan could be developed.

The survivability problem was to be solved by a "rail garrison" system whereby 25 trains, each with two missiles, would use the national railroad system to conceal themselves. It was intended that this system would become operational in late 1992, but budgetary constraints and the changing international situation led to it being scrapped.

The project had cost around $20 billion up to 1998 and produced 114 missiles, at $400 million for each operational missile. The "flyaway" cost of each missile is estimated at $20–70 million.

The missiles were gradually retired, with 17 withdrawn during 2003, leaving 29 missiles on alert at the beginning of 2004. At the start of 2005 only 10 remained on alert, scheduled to be retired by the end of the year. The last Peacekeeper was removed from alert on September 19, 2005 during the final deactivation ceremony when the 400th Missile Squadron inactivated as well.[2] The rockets are being converted to a satellite launcher role by Orbital Sciences, as the OSP-2 Minotaur IV SLV, while their warheads will be deployed on the existing Minuteman III missiles.

Operational test launches were performed by the men and women of the 576th Flight Test Squadron at Vandenberg AFB, California. This squadron is also the home of "TOP HAND", a board-selected professional development program for missile launch officers.

Testing at the Kwajalein Atoll of the Peacekeeper re-entry vehicles, all eight fired from only one missile.  With live warheads, each line would represent the explosive power of twenty Hiroshima-sized (Little Boy) weapons.
Testing at the Kwajalein Atoll of the Peacekeeper re-entry vehicles, all eight fired from only one missile. With live warheads, each line would represent the explosive power of twenty Hiroshima-sized (Little Boy) weapons.

[edit] Operator

[edit] References

[edit] External links

[edit] See also

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