"Minuteman III" ICBM
Published October 01, 2007
Boeing LGM-30G "Minuteman III" ICBM
Propulsion: Three solid-propellant rocket engines; first, second and third stages of 200,000, 60,600 and 34,000 pounds of thrust, respectively
Diameter: 6 ft at widest point
Length: 59 ft 10 in
Weight: 78,000 lbs (at launch)
Speed: 15,000 mph (max)
Range: Over 8,000 miles
Service Ceiling: 700 miles
Armament: Nuclear warheads
Even before the first LGM-30F Minuteman II had been deployed, work was already underway on the ultimate version of the missile, the LGM-30G Minuteman III.
The Autonetics and Rocketdyne Divisions of North American Rockwell had joined forces in 1964 to create a post-boost propulsion system for correcting the altitude, attitude, and velocity of the reentry vehicle after separation from the third stage. This new innovation used an advanced guidance and control system, a restartable liquid-fueled rocket motor, and three Multiple Independently-targeted Reentry Vehicles (MIRVs), each with its own nuclear warhead, to allow one Minuteman missile to attack three independent targets with extreme accuracy.
The first Minuteman III launch came in August 1968 and the first silo launch came on April 11, 1969. The first emplacement was in April 1970 and deployment ended in July 1976. Production of the Minuteman III ICBM ended on January 14, 1977. A total of 550 of the missiles were originally deployed.
To improve the Minuteman III system's capabilities even further, an upgrade was undertaken in the 1970s simultaneously with the development of the Martin Marietta LGM-118A Peacekeeper ICBM. Some have called these updated LGM-30G missiles the "Minuteman IV," but the official designation was never changed. The upgrades improved the aiming accuracy of the missile.
Another improvement program in the 1980s fitted more powerful warheads to the missile. Other improvements, such as the Airborne Launch and Control System based on the EC-135 and E-6B aircraft, were fitted to the entire Minuteman fleet during the 1980s to make the force more reliable and survivable in the event of a nuclear attack on the United States. Test flights were also made in which a Minuteman III carried seven MIRVs aloft instead of three, but that change was never implemented in the fleet.
As the Logistics System Program Manager for the nation's entire ICBM force, the Ogden Air Logistics Center at Hill AFB had a close working relationship with all ICBM systems, including the Minuteman family. On January 6, 1959 the base was assigned the management of the SM-80 Minuteman ICBM program. Later that year construction began on Air Force Plant 77 in the West Area of the base. This facility would be owned by the Air Force and operated by Boeing, and would be the final assembly and recycling point for all Minuteman missiles. From here all operational missiles would be delivered to their launch sites by either truck, rail, or air transportation.
In November 1962 the first air shipment of a Minuteman took place when a C-133 transported a missile from Hill to its launching site at Malmstrom AFB, Montana. In January 1963 the first Minuteman missile to be repaired at AF Plant 77 was completed.
In July 1965 the Ogden Air Materiel Area assumed complete logistics management for the entire Minuteman I missile force, all 800 missiles operated by the Strategic Air Command. The following month the first Minuteman II came off the AF Plant 77 assembly line. In January 1966 USAF officials dedicated the $12.5 million Minuteman Missile Engineering Test Facility at Hill, the first and only complete system engineering test facility for an operational missile in the USAF inventory. In June 1967 groundbreaking was held for a new $16.5 million Minuteman II Engineering Test Facility.
On June 26, 1968 the first Minuteman III training missile was shipped from AF Plant 77 to the Boeing Company in Seattle for acceptance testing and check out. This was the lead item in the Minuteman III program. In April 1970 the first operational LGM-30G to be airlifted out of Hill left aboard a C-141. In July 1975 Hill personnel on temporary duty at Malmstrom AFB, Montana, completed installation of the Minuteman III fleet.
Air Force Plant 77 closed on November 30, 1978. As part of the closing ceremonies, representatives of the Air Force accepted the last production Minuteman III missile.