LGM-30G Minuteman-III

LGM-30 Minuteman
Type	Intercontinental ballistic missile
Place of origin	United States
Service history
In service	1962 (Minuteman-I) 1965 (Minuteman-II) 1970 (Minuteman-III)
Used by	United States
Production history
Manufacturer	Boeing
Unit cost	$7,000,000
Specifications
Weight	78,000 lb (35,300 kg)
Length	59 ft 9.5 in (18.2 m)
Diameter	5 ft 6 in (1.7 m) (1st stage)
Warhead	Nuclear: W62 (retired), W78 (active), or W87 (active)
Detonation mechanism	Air-burst or contact (surface)
Engine	Three-stage solid-fuel rocket engines; first stage: Thiokol TU-122 (M-55); second stage: Aerojet-General SR-19-AJ-1; third stage: Aerojet/Thiokol SR73-AJ/TC-1
Operational range	Approx. 8,100 miles (13,000 km), exact is classified
Flight altitude	700 miles (1,120 kilometers)
Speed	Approximately 17,507 mph (Mach 23, or 28,176 km/h, or 7.8 km/s) (terminal phase)
Guidance system	Inertial NS-50
Accuracy	200 m CEP
Launch platform	Missile silo

The LGM-30 Minuteman is a U.S. land-based intercontinental ballistic missile (ICBM), in service with the Air Force Global Strike Command. As of 2017, the LGM-30G Minuteman III version is the only land-based ICBM in service in the United States.

Development of the Minuteman began in the mid-1950s as the outgrowth of basic research into solid fuel rocket motors which indicated an ICBM based on solids was possible. Such a missile could stand ready for extended periods of time with little maintenance, and then launch on command. In comparison, existing U.S. missile designs using liquid rocket propellant required a lengthy fueling process immediately before launch, which left them open to the possibility of surprise attack. This potential for immediate launch gave the missile its name; like the Revolutionary War's Minutemen, the Minuteman was designed to be launched on a moment's notice.

Minuteman entered service in 1962 as a weapon tasked primarily with the deterrence role, threatening Soviet cities with a second strike countervalue counterattack if the U.S. was attacked. However, with the development of the U.S. Navy's Polaris which addressed the same role, the Air Force began to modify Minuteman into a weapon with much greater accuracy with the specific intent of allowing it to attack hardened military targets, including Soviet missile silos. The Minuteman-II entered service in 1965 with a host of upgrades to improve its accuracy and survivability in the face of an anti-ballistic missile (ABM) system the Soviets were known to be developing. Minuteman-III followed in 1970, using three smaller warheads instead of one large one, which made it very difficult to attack by an anti-ballistic missile system which would have to hit all three widely separated warheads to be effective. Minuteman-III was the first multiple independently targetable reentry vehicle (MIRV) ICBM to be deployed. Each missile can carry up to three thermonuclear weapons, which have a yield in the range of 300 to 500 kilotons.