Minuteman II

The LGM-30F Minuteman II was an intercontinental-range, silo-based, solid-fueled ballistic missile. It was the second generation of the Minuteman ICBM family, following the Minuteman I.

Minuteman II at a Glance

Originated From: United States
Possessed By: United States
Class: Intercontinental Ballistic Missile (ICBM)
Basing: Silo-based
Length: 18.2 m
Diameter: 1.87 m (first stage), 1.31 m (second stage)
Launch Weight: 31,746 kg
Payload: Single warhead, Mk 11C RV with penetration aids
Warhead: W-56, 1.2 mT Nuclear
Propulsion: Three-stage, solid propellant
Range: 12,500 km
Status: Obsolete
In Service: 1965-1994

minuteman ii

Minuteman II Development

The development of the LGM-30F Minuteman II started in October 1963, less than a year after the Minuteman I came into use. In many respects, the Minuteman II was a tuned-up version of its predecessor.1 The Minuteman II added an improved guidance system which used miniaturized electronic circuits and components. The use of these components in the guidance system allowed for multiple target selection, a higher degree of accuracy, reduced the weight of the guidance system, and improved the systems’ reliability.  Additionally, it used an elongated motor assembly which allowed for more fuel storage and increased the systems’ reliability, range, and payload capacity. This increase in payload capacity was necessary for the missile to carry the heavier 1.2 mT warhead and more penetration aids, increasing the chance that the missile could destroy an enemy silo.2

The first Minuteman II test took place in September 1964 and met all objectives.3 Other early tests proved successful as well, leading to an expedited deployment.  The missile entered service in 1965.4

Service History

The Minuteman II entered service in 1965 and production of the missile ended in 1967. By 1969, most of the 800 Minuteman I missiles had been replaced by Minuteman IIs.  While some new silos were constructed, many of the new Minuteman missiles were placed in the old silos. Due to the more advanced capabilities and larger dimensions of the new missile, the launch control centers and Minuteman I silos chosen to house the second generation Minuteman had to be upgraded and expanded.5

Like the rest of its series, the Minuteman II was designed to be deployed in large numbers in order to force potential enemies to expend their nuclear arsenal attacking silos instead of cities.  As such, it formed the “quantity” component of the U.S. nuclear triad’s land-based leg.6 The missile’s lower yield and single warhead designs were offset by the Titan II and Peacekeeper missiles respectively.

Due to strategic arms reduction treaties between the U.S. and the Soviet Union, only 450 Minuteman IIs were listed as being in service by 1990.  After the Soviet Union’s collapse on December 26, 1991, the United States began retiring the Minuteman IIs, with all missiles being rendered non-operational by 1995.7

Upon decommissioning, a number of deactivated Minuteman II missiles were converted into orbital and sub-orbital launch vehicles. The U.S. also began to use the Minuteman II to deploy or act as anti-ballistic missile test targets and to test missile defense radar systems.8 The missile was also used as a surrogate booster for Exo-atmospheric Kill Vehicles (EKV) between 1997 and 2002.9 Despite the missile being out of production, Aerojet Corporation built an additional 60 Minuteman II second stage boosters for use in developing anti-missile defense systems. 10

On December 15, 1997, the last Minuteman II silo was destroyed at Whitman Air Force Base in Missouri.11

Specifications

The Minuteman II had a range of 12,500 km (7,767 miles) and an accuracy of 200 m CEP. The accuracy was obtained by an inertial navigation system controlled by a pre-programmed digital computer. The missile carried a single Mark 11C RV equipped with penetration aids to decrease the effectiveness of Soviet anti-missile systems. The RV had a W56 nuclear warhead with a yield of 1.2 MT. The missile had a length of 18.2 m, a maximum body diameter of 1.8 and a launch weight of 31,746 kg. It had a three-stage solid propellant engine.12

    1. Federation of American Scientists, “LGM-30F Minuteman II,” https://fas.org/nuke/guide/usa/icbm/lgm-30_2.htm, February 16, 2017.
    2. ICBM System Program Office, “Minuteman Weapon System History and Description,” July 2001, 31.
    3. “Minuteman 2 Hits Bullseye in First Test,” in Chicago Tribune, September 25, 1964.
    4. Thomas Cochran, “Minuteman II” in U.S. Nuclear Forces and Capabilities (Cambridge: Ballinger Publishing Company, 1984), 113.
    5. The Military Standard, “LGM-30F Minuteman II Overview,” http://themilitarystandard.com/missile/minuteman2/overview.php, February 17, 2017.
    6. ICBM Systems Program Office, 11-12.
    7. Ibid, 13.
    8. Veronique de Turenne, “The twilight launch of a Minuteman II missile from…,” Los Angeles Times, June 24, 1997.
    9. Missile Defense Agency, “Missile Defense Tests Conducted,” News Release, December 11, 2002.
    10. Duncan Lennox, “LGM-30F Minuteman II” in Jane’s Strategic Weapon Systems (Offensive Weapons) (London: IHS Global, 2011.)
    11. Federation of American Scientists, “Last Minuteman II missile silo imploded,” https://fas.org/nuke/guide/usa/icbm/n19971222_971628.html, February 16, 2017.
    12. Lennox.