LGM-30F Minuteman II
In service since 1965, the Minuteman "F" was a three stage, solid propellant, intercontinental ballistic missile. Because solid propellant is so stable in storage, the missile can be stored almost indefinitely and yet be ready to launch on short notice. This ICBM had a range of over 7,000 nautical miles and carried a single nuclear warhead. 450 missiles were fielded at one time, though the Minuteman II has been decommissioned and the missiles disassembled.
Even as the Minuteman I program raced forward, the Air Force began developing the new Minuteman II. On 2 October 1963, shortly after the first model "A" and "B" Minuteman I squadrons achieved operational status, Headquarters USAF issued Annex A to Specific Operational Requirement 171 which established a requirement for the Minuteman II ICBM (Model "F").
The new missile was a significant improvement over its predecessor. A more advanced missile than either model of the Minuteman I, the "F" model incorporated a new, larger second-stage, improved guidance system, a greater range and payload capacity, and an increased capability to survive the effects of nuclear blast. A new second-stage motor with a single nozzle and a secondary liquid injection for thrust vector control increased the missile's range from 6,300 to 7,000 miles. The new motors also enabled the Minuteman to carry the larger W-56 warhead with a yield of 1.2 megatons. An improved guidance system made the missile more accurate, and it could store a larger number of preprogrammed targets within its internal memory. Moreover, Minuteman Il also carried penetration aids to camouflage the reentry vehicle during reentry.
In view of the numerous advantages of the Minuteman II, Secretary of Defense Robert S. McNamara approved the Minuteman Force Modernization Program on 8 November 1963. The project entailed the eventual replacement of the entire force of deployed Minuteman I ICBMs, 150 "A" and 650 "B" models, with Minuteman IIs.
The Air Force awarded Boeing the Minuteman II contract in March 1962 and the Seattle-based contractor conducted the first test flight in September 1964. In May 1966 SAC placed its first Minuteman II squadron on operational alert, and by April 1967, accepted its 200th Minuteman 11. At that point the Minuteman force stood at 1,000 missiles; 800 Minuteman Is and 200 Minuteman IIs. Continuing its missile modernization effort, throughout the late 1960s the Air Force replaced many of its Minuteman Is with Minuteman Hs, and by May 1969 it had 500 Minuteman Is and an equal number of Minuteman IIs on operational alert.
To prepare for the emplacement of the newer model Minuteman II ICBM, it was necessary to completely retrofit the original Minuteman I launch facilities, launch control facilities, and associated ground equipment. The Minuteman Force Modernization Program began at Whiteman Air Force Base, Missouri, on 7 May 1966 when the first flight of ten model "B" Minuteman missiles were removed from their silos at the 509th Strategic Missile Squadron. On 1 February 1965, Headquarters SAC activated the 447th SMS at Grand Forks AFB, North Dakota, making it the seventeenth Minuteman squadron and the first to be equipped with "F" model missiles. Fourteen months later on 1 April 1966, SAC activated the fourth Minuteman II, and the twentieth and last Minuteman squadron, the 564th SMS, at Malmstrom AFB, Montana. Once the 564th SMS achieved operational status on 21 April 1967, the deployment of the programmed force of 1,000 Minuteman ICBMs was completed.
In FY96, the last Minuteman II booster was dismantled at Hill AFB, UT, and turned over to the Rocket System Launch Program. All Minuteman II silos at Ellsworth AFB, SD, have been destroyed, with the exception of one National Park Service missile site. Approximately 1/3 of the sites at Whiteman AFB, MO, had been destroyed by FY96, with the remainder programmed for FY97.
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