LGM-30A/B Minuteman I

In the late 1950s advances in solid-fuel propellants enabled the Air Force to develop its first solid-fuel ICBM, the Minuteman I (LGM-30A/B). Formal development began in September 1958, and after an extraordinarily rapid development program, the Air Force put its first ten Minuteman ICBMs on operational alert at Malmstrom AFB, Montana, in October 1962. Deployment proceeded at an equally furious pace, and within 5 years 1,000 of the solid-fuel missiles stood poised in their silos.

Minuteman is a three-stage, solid-propellant, rocket-powered ICBM with a range of approximately 5,500 nautical miles. Minuteman also possessed an all-inertial guidance system and the capability of being fired from hardened and widely-dispersed underground-silo launchers. A consortium of five contractors produced four distinct models of the Minuteman ICBM weapon system, each model being an improvement over the former: Minuteman I (models "A" and "B"), Minuteman II (model "F"), and Minuteman III (model "G"), the latter capable of carrying multiple independently-targetable reentry vehicles (MIRVs).

The Western Development Division (WDD) was interested in solid-fuel ICBMs in 1954, but at the time found that solid-fuel motors did not produce sufficient thrust and were difficult to control. The Air Force, however, did not abandon the technology, and the WDD and the Wright-Patterson Air Development Center sponsored research in solid fuels throughout the mid-1950s.

By the spring of 1957, Air Force research indicated that a solid-fuel ICBM was possible. That fall the Air Force Ballistic Missile Division's (AFBMD-it changed its name effective June 1, 1957) Col. Edward Hall designed the revolutionary Minuteman ICBM. In marked contrast to the first generation Atlas and Titan I liquid-fuel missiles, Hall proposed building a relatively small, three-stage solid-fuel missile that would be inexpensive to build and maintain. He envisioned basing thousands of the missiles in unmanned, heavily hardened and widely dispersed silos linked electronically to a series of central launch control facilities.

The Air Force was initially cool toward the new concept, but was spurred into action when the Navy proposed modifying its Polaris submarine-launched ballistic missile (SLBM) for use as an ICBM. Anxious to defend its role in solid-fuel development, in February 1958 AFBMD sent Hall to Washington to brief the Secretary of Defense, the Secretary of the Air Force, and the Strategic Air Command's General Curtis LeMay on the Minuteman concept. They were impressed with the program, and quickly allocated the AFBMD $50 million to begin research and promised the development center another $100 million if they proved that the Minuteman was indeed feasible.

In July 1958 AFBMD began to develop the components and select the contractors. By the following September the missile development command had made sufficient progress to convince the Air Force to support full Minuteman system development, and the following month the AFBMD chose the Boeing Airplane Company as the missile assembly and test contractor. Shortly thereafter, the AFBMD awarded the guidance contract to the Autonetics Division of North American Aviation (later a Division of Rockwell International) and the reentry vehicle contract to AVCO Corporation. Todevelop the first-, second-, and third-stage motors AFBMD sponsored a competition between the Thiokol Chemical Corporation, the Aerojet General Corporation, and the Hercules Powder Company. The Air Force awarded the initial contracts with the under-standing that the company with the most promising design would win the production contract.

In September 1959 the AFBMD successfully launched a Minuteman first stage motor directly from an underground silo, thus proving that the missile would survive the rigors of a subsurface launch. In February 1961 the AFBMD launched a Minuteman containing all three stages and operational subsystems from the Air Force Missile Test Center in Florida. This was called an "all up" test. The missile performed flawlessly and after a flight of 4,600 miles its reentry vehicle landed within the designated impact zone.

Based on the success of the initial test flight, in March 1961 the Department of Defense formally accelerated the Minuteman program and gave it the same development priority as the Atlas and Titan ICBM programs. In November 1961 the AFBMD launched a complete Minuteman from a silo at the Operational Standardization andTest Facility (OSTF) at Vandenberg AFB, California. The missile recorded a successful flight of 3,000 miles.

In conjunction with the Minuteman development effort, the Army Corps of Engineers Ballistic Missile Construction Office (CEBMCO) built the launch facilities. Construction of the launch facilities and launch control centers at the first Minuteman squadron at Malmstrom AFB, Montana began in March 1961 and was completed late the following September. On October 22, 1962, SAC placed its first flight of ten Minuteman missiles on operational alert.

Deployment of the Minuteman force was accomplished with amazing speed. The Minuteman launch facilities were much smaller and easier to build than the Atlas and Titan launch facilities. Using prefabricated components and standardized construction techniques, CEBMCO built 1,000 silos by 1966.

From its very inception, the Minuteman program was oriented towards mass production of a simple, efficient, and highly survivable ICBM capable of destroying all types of enemy targets with consistent reliability. The Air Force hoped that such a program would reverse the unfavorable trend towards succeeding generations of progressively more costly ICBMs and provide the Strategic Air Command with a weapon system that was inexpensive to operate and maintain.

During the early development phase of Minuteman, the Strategic Air Command favored the concept of deploying at least a portion of the programmed force (from 50 to 150 ICBMs) on railroad cars. SAC submitted a requirement to the Air Staff on 12 February 1959 calling for the first mobile Minuteman unit to be operational no later than January 1963. To determine the feasibility of deploying Minuteman ICBMs on mobile launchers, SAC ordered a series of tests to be conducted, nicknamed "Operation Big Star." Beginning 20 June 1960, a modified test train, operating out of Hill Air Force Base, Utah, traveled across the western and central United States so technicians could study factors such as the ability of the nation's railroads to support mobile missile trains; problems associated with command, control, and communications; the effect of vibration on sensitive missiles and launch equipment; and human factors involved in the operation of a mobile missile system. Originally, six trial runs were projected, but only four were necessary to realize all test objectives. On 27 August 1960, the last of four Minuteman ICBM test trains arrived back at Hill AFB and the Air Force announced that the test of the Minuteman mobility concept had been completed satisfactorily.

Despite SAC's repeated pleas in favor of mobile Minuteman, the Air Force assigned top priority to the fixed silo-based Minuteman concept. Furthermore, on 28 March 1961, President John F. Kennedy deferred further action on the development of the three mobile Minuteman squadrons in favor of three additional squadrons of silo-based Minuteman units. Secretary of Defense Robert S. McNamara finally settled the issue on 7 December 1961 when he canceled the mobile Minuteman development program.

Minuteman I was deployed in two variants, Minuteman I/A and I/B. Minuteman I/A was an interim weapon because a flawed first stage reduced its range by 2,000 miles. Rather than delay the entire Minuteman program while it corrected the problem, the Air Force elected to go ahead and deploy 150 Minuteman I/As. By July 1963 150 Minuteman missiles were on operational alert; that number increased to 300in October 1963, 450 by March 1964, and in June 1965 the 800th Minuteman I missile was turned over to its SAC crew at F.E. Warren AFB, Wyoming.

A decision regarding the final size of the silo-based Minuteman ICBM force was not made until December 1964. A new Minuteman system program directive issued on 11 December 1964 established the final Minuteman force at 1,000 missiles. Three years earlier, on 1 December 1961, Headquarters SAC had activated the first Minuteman squadron, the 10th Strategic Missile Squadron (ICBM-Model A Minuteman I) at Malmstrom Air Force Base, Montana. Only two other model "A" ICBM squadrons were activated by Headquarters SAC. These were the 12th Strategic Missile Squadron, activated on 1 March 1962, and the 490th Strategic Missile Squadron, activated on 1 May 1962, also located at Malmstrom. The next thirteen Minuteman squadrons activated by the Strategic Air Command were all model "B" Minuteman I units.

Strategic Air Command housed each Minuteman I, whether a model "A" or "B", in an unmanned, hardened, and widely-dispersed (three-to-seven mile intervals) underground-silo launch facility. A missile combat crew of two officers stationed in a hardened, underground launch control center monitored each flight of 10 launch facilities (five flights per squadron). For purposes of command, control, and communications, hardened underground cables linked all five launch control centers of a Minuteman squadron.

The Minuteman Force Modernization Program initiated in 1966 to replace all Minuteman I's with either Minuteman II's or Minuteman III's continued through the latter 1960s and into the mid-70s. The last Minuteman I series "An missiles were removed from their launch facilities at Malmstrom AFB, Montana, on 12 February 1969. These facilities were refurbished and outfitted with Minuteman II series "F" missiles. Boeing Aerospace Company, the contractor responsible for remodeling the launch facilities, completed the nine year modernization effort on 26 January 1975 when it turned over to SAC the last flight of ten Minuteman III missiles at the 90th Strategic Missile Wing, F.E. Warren AFB, Wyoming. The Minuteman I was deactivated in 1972 when the Air Force began it's modernization process to the Minuteman III.