Encyclopedia Astronautica
Minuteman



m030a.jpg
Minuteman 1
Credit: via Andreas Parsch
American intercontinental ballistic missile. Mainstay of the US deterrent. 1,000 Minuteman silos were built in the early 1960's, and the missile was to remain in service to the mid-21st Century. As versions were retired and updated, they provided a plentiful source of surplus rocket motors for other projects.

The operational drawbacks of the first generation liquid-propellant Atlas and Titan ICBM's were apparent. The use of liquid oxygen oxidizer meant they were not ready for immediate launch; they took dozens of minutes to fuel. The Soviet Union's ICBM's could destroy them in a first strike while still on their pads. Clearly a launch-on-command solid propellant weapon would be the answer, but in the early 1950's solid propellant technology was not ready. However a series of development motors of increasing size and performance made the solid propellant ICBM feasible by 1957.

The Minuteman program was started in February 1958, with Boeing selected as prime contractor in October. Use of three stages, new miniaturized inertial navigation systems, and small nuclear warheads meant that the Minuteman would have a fraction of the cost, weight, and silo size of the Atlas and Titan missiles it would replace. The perceived (but non-existent) missile gap with the Soviet Union and the vulnerability of the Atlas missiles made Minuteman the highest national priority. 1,000 silos were to be built across the United States in one of the largest construction projects in history. First test launches began in 1960; first silo launch in November 1961. The first of 150 provisional Minuteman IA missiles became operational in November 1962. Deployment of 650 production-standard Minuteman IB's took place between April 1963 to June 1965. Plans to develop a mobile train-launched version of the missile were dropped in December 1961. Minuteman I's were progressively replaced by later Minuteman II and III models, with the last IA being retired in 1969, and the last IB in 1974.

Failures: 46. Success Rate: 94.64%. First Fail Date: 1959-09-15. Last Fail Date: 2000-05-24. Launch data is: complete. Development Cost $: 2,095.300 million. Recurring Price $: 4.946 million in 1964 dollars. Flyaway Unit Cost $: 1.320 million in 1960 dollars. Initial Operational Capability: 1963. Total Number Built: 925. Total Development Built: 125. Total Production Built: 800.

Historical Essay © Andreas Parsch

Boeing SM-80-LGM-30 Minuteman 1

The Minuteman was the world's first solid-fueled Intercontinental Ballistic Missile (ICBM), and has been the mainstay of the USAF's ICBM force ever since its deployment. Because international arms reduction treaties will lead to the early retirement of its designated successor, the LGM-118 Peacekeeper, the Minuteman will soon be the only land-based strategic missile of the United States, and remain so for the foreseeable future.

Solid-fueled rockets have obvious advantages when compared to liquid-fueled ones, the most important being very long storage life of the motors, and the lack of time-consuming and potentially dangerous fueling processes. However, when ICBM development began in the 1950s, very large solid rockets were beyond the technology of the time. However, progress was made, and by mid-1957, pre-development studies for a solid-fueled ICBM were firmly under way. In February 1958, the Minuteman program was officially started, and in October that year, Boeing was selected as prime contractor for the new SM-80 Minuteman ICBM.

The SM-80 was a three-stage design, using in its initial version Thiokol M55, Aerojet General M56, and Hercules M57 solid rocket motors for the stages. Auxiliary solid-fuel rocket motors used in the Minuteman design included a Hercules SR11-HP-1 retro motor, and Atlantic Research SR59-AR-1 pitch and SR61-AR-1 spin motors. The missile was guided by an all-inertial navigation system. It was originally planned to base the SM-80 not only in hardened silos, but also on special trains, using the nation's railway network to create mobile ICBM squadrons which would have been all but immune to a pre-emptive strike. However, this plan was dropped in December 1961 for financial reasons. Tests of XSM-80 Minuteman prototypes began in 1960, and in November 1961 the first successful silo launch of an XSM-80 occurred. The first production missiles, designated HSM-80A Minuteman IA, became operational in November 1962. A total of 150 Minuteman IA missiles were deployed in silos.

The Minuteman IA missile was somewhat limited in firepower (its W-59 warhead had a yield of 1.2 MT) when compared to the contemporary SM-65-CGM-16 Atlas and SM-68-HGM-25 Titan missiles. The HSM-80A's guidance system could store only one set of target coordinates, so it was less flexible than later Minuteman models. However, because it could be launched instantly, the Minuteman was the first missile which could make the horror vision of nuclear "turnkey" warfare a reality. Elaborate schemes were therefore set up to prevent accidental or unauthorized firing of the missiles by the launch crews.

The improved HSM-80B Minuteman IB was first deployed in April 1963. The HSM-80B replaced some HSM-80As, and deployment was finished in June 1965 with 650 missiles in silos. The Minuteman IB featured an improved second-stage motor, and a new reentry vehicle and larger warhead, increasing range and firepower. Its guidance unit could store two targets, enabling the missile to switch to a secondary target after launch if the primary couldn't be reached for any reason.

When the mobile basing requirement for the Minuteman was cancelled in December 1961, this also lifted some restrictions on missile size and weight. It was now possible to increase the performance by enlarging rocket stages, as long as the missile would still fit into the silos. Therefore the USAF began the Minuteman II program in 1962, with the missile being designated as HSM-80F. I haven't found any traces of -80C, -80D, or -80E designations, so these were either skipped for unknown reasons, or assigned to preliminary or interim designs before the final Minuteman II. Details of the HSM-80F are discussed below under its post-1963 designation of LGM-30F.

In June 1963, all Minuteman missiles were redesignated in the LGM-30 series as follows:

Old Designation New Designation
XSM-80 XLGM-30A
HSM-80A LGM-30A
HSM-80B LGM-30B
HSM-80F LGM-30F

Suffixes -30C, -30D, and -30E were not assigned.

AKA: LGM-30A.
Status: Retired 1993.
First Launch: 1959.09.15.
Last Launch: 2008.11.05.
Number: 380 .

More... - Chronology...


Associated Countries
Associated Spacecraft
  • KE ASAT American military anti-satellite system. Study 1989. In 1989 the US Army began a demonstration/validation program to develop a direct ascent kinetic energy ASAT for US forces. More...

See also
  • Minuteman Mainstay of the US deterrent. 1,000 Minuteman silos were built in the early 1960's, and the missile was to remain in service to the mid-21st Century. As versions were retired and updated, they provided a plentiful source of surplus rocket motors for other projects. More...
  • missile Guided self-propelled military weapon (as opposed to rocket, an unguided self-propelled weapon). More...

Associated Manufacturers and Agencies
  • Boeing American manufacturer of rockets, spacecraft, and rocket engines. Boeing Aerospace, Seattle, USA. More...

Bibliography
  • McDowell, Jonathan, Jonathan's Space Home Page (launch records), Harvard University, 1997-present. Web Address when accessed: here.
  • Emme, Eugene M, Aeronautics and Astronautics: An American Chronology of Science and Technology in the Exploration of Space 1915-1960, NASA, 1961. Web Address when accessed: here.
  • Gunston, Bill,, Rockets and Missiles, Salamander, London, 1979.
  • Nicholas, Ted G., U.S. Missile Data Book, 1983, Seventh Edition, Data Search Associates, Fountain Valley, California, 1982..
  • Parsch, Andreas, DesignationSystems.Net, Web Address when accessed: here.

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