The LGM-30 Minuteman is an American nuclear missile, a land-based intercontinental ballistic missile (ICBM). As of 2009, it is the only land-based ICBM in service in the United States. It is complemented by the sea-launched Trident missile SLBM and by nuclear weapons carried by long-range strategic bombers; see current status of United States nuclear weapons.

The “L” indicates that the missile is silo-launched; the “G” indicates that it is designed to attack ground targets; the “M” indicates that it is a guided missile.

The name “Minuteman” comes from the Revolutionary War’s Minutemen. It also refers to its quick reaction time; the missile can be launched in about 1 minute. The Air Force planned to keep the missile in service until 2020, but it may be upgraded to stay in service until 2030.

Current model

The current Minuteman force consists of 450 Minuteman III missiles in missile silos around F.E. Warren AFB, Wyoming; Malmstrom AFB, Montana; and Minot AFB, North Dakota.

It is a guided missile with three solid-fuel stages, and in the post-boost stage (“bus”), a liquid-fuel propulsion system rocket engine is used to fine-tune the trajectory of the reentry vehicle and/or dispense individual warheads to separate targets. The missile has a gimballed inertial guidance system.

The third stage has precision shutdown ports which, when opened, reduce the chamber pressure so abruptly that the interior flame is blown out. This allows a more precise trajectory which improves targeting accuracy. The post-boost stage carries, in addition to the warheads, penetration aids such as chaff and decoys.

The Minuteman III missile entered service in 1970, with weapon systems upgrades included during the production run from 1970 to 1978 to increase accuracy and payload capacity. As of 2007, USAF plans are to operate it until 2040.

The LGM-118A Peacekeeper (MX) ICBM, which was to have replaced the Minuteman, was retired in 2005 as part of START II.

Guidance Replacement Program (GRP)

The Guidance Replacement Program (GRP) replaces the NS20A Missile Guidance Set with the NS50A Missile Guidance Set. The newer system extends the service life of the Minuteman missile beyond the year 2020 by replacing aging parts and assemblies with current, high reliability technology while maintaining the current accuracy performance.

Propulsion Replacement Program (PRP)

Beginning in 1998 and continuing through 2009 , the Propulsion Replacement Program extends the life and maintains the performance by replacing the old solid propellant boosters (downstages).

Single Reentry Vehicle (SRV)

The Single Reentry Vehicle (SRV) modification allows the United States ICBM force to abide by START I treaty requirements by reconfiguring Minuteman-III missiles from three reentry vehicles down to one.

Safety Enhanced Reentry Vehicle (SERV)

Beginning in 2005, Mk-21/W87 RVs from the deactivated Peacekeeper missile will be placed on the Minuteman-III force under the Safety Enhanced Reentry Vehicle (SERV) program. The older W78 currently used is not equipped with important safety features. In addition to adding additional safety features into at least a portion of the future Minuteman-III force, the decision to transfer W87s onto the missile is based on two features that will improve the targeting capabilities of the weapon: more fuzing options which will allow for greater targeting flexibility and the most accurate reentry vehicle available which provides a greater probability of damage to the designated targets. The first SERV moded Minuteman III was put on alert status at FE Warren AFB, Wyoming, in 2006.

Organization

The basic tactical unit of a Minuteman wing is the squadron, consisting of five flights. Each flight consists of ten unmanned launch facilities (LFs) which are remotely controlled by a manned launch control center (LCC). The five flights are interconnected and status from any LF may be monitored by any of the five LCCs. Each LF is located at least three nautical miles (5.6 km) from any LCC. Control does not extend outside the squadron (i.e. The 319th Missile Squadron’s five LCCs cannot control the 320th Missile Squadron’s 50 LFs). Each Minuteman wing is assisted logistically by a nearby Missile Support Base (MSB).

Operator

: The United States Air Force is the only operator of the Minuteman III, with three operational wings and one test squadron operating the LGM-30G. The active inventory in FY 2009 is 450 missiles and 45 launch control centers.

Academic Instruction Units

• 532d Training Squadron - Vandenberg AFB, California (Missile Maintenance: "the most important piece of the pie")
• 392d Training Squadron - Vandenberg AFB, California (Missile Initial Qualification Course)
• 328th Weapons Squadron - Nellis AFB, Nevada (ICBM Weapons Instructor Course)

Active Units

• 526th ICBM Systems Wing — Hill Air Force Base, Utah

• 576th Flight Test Squadron — Vandenberg Air Force Base, California — “Top Hand”

• 625th Strategic Operations Squadron - Offutt AFB, Nebraska - Strategic Nuclear Targeting

• 341st Missile Wing (Wing I) — Malmstrom Air Force Base, Montana — “Grizzlies”
  • 10th Missile Squadron — “First Aces”
  • 12th Missile Squadron — “Red Dawgs”
  • 490th Missile Squadron — “Farsiders”

• 91st Missile Wing (Wing III) — Minot AFB, North Dakota — “Roughriders”
  • 740th Missile Squadron — “Vulgar Vultures”
  • 741st Missile Squadron — “Gravelhaulers”
  • 742d Missile Squadron — “Wolf Pack”

• 90th Missile Wing (Wing V) — F.E. Warren Air Force Base, Wyoming
  • 319th Missile Squadron — “Screaming Eagles”
  • 320th Missile Squadron
  • 321st Missile Squadron — “Frontier Warriors”

Former Units

• 44th Missile Wing (Wing II) — Ellsworth Air Force Base, South Dakota — “Black Hills Bandits” — Deactivated 4 July 1994
  • 66th Missile Squadron
  • 67th Missile Squadron
  • 68th Missile Squadron

• 341st Missile Wing — Malmstrom Air Force Base, Montana
  • 564th Missile Squadron — Deactivated 15 August 2008.

• 351st Missile Wing (Wing IV) — Whiteman Air Force Base, Missouri — Deactivated 31 July 1995
  • 508th Missile Squadron
  • 509th Missile Squadron
  • 510th Missile Squadron

• 321st Missile Wing (Wing VI) — Grand Forks Air Force Base, North Dakota — Deactivated 31 July 1995 (321st Missile Group inactivated 2 July 1998)
  • 446th Missile Squadron
  • 447th Missile Squadron
  • 448th Missile Squadron

• 90th Missile Wing, F.E. Warren AFB, WY.
  • 400th Missile Squadron - deactivated 19 Sept 2005.

History

The Minuteman-I and Minuteman-II were in service from 1960 until 1997. The Minuteman-III was first deployed in 1969 and with the latest upgrades is expected to remain in service through the year 2025.

The Minuteman had two innovations that gave it a long practical service life: a solid rocket booster, and a digital flight computer. This computer was one of the very first recognizably modern embedded systems.

The solid rocket booster made the Minuteman faster to launch than other ICBMs, which used liquid fuels. A crucial innovation in this area was to include a valve to release the booster pressure, and permit effective throttling of the booster.

A reprogrammable inertial guidance system was a major risk in the original program. When first proposed, no one had built a digital computer that would fit in a missile. One program, the SM-64 Navaho, had already failed to produce such a system.

A digital computer was essential to obtain the accuracy gains that kept this weapon effective throughout the Cold War. As the Defense Mapping Agency (now part of National Geospatial-Intelligence Agency) more accurately mapped mass concentrations in the Earth, the inertial guidance software could be updated and loaded into the missiles to make them ever more accurate by having them compensate for these sources of gravity. Another gain that persuaded program managers to accept the risk of the computer was that the computer could also be used to test the missile. This saved a large amount of weight in cables and connectors.

Minuteman-I (LGM-30A/B or SM-80/HSM-80A)

See also W56 Warhead

Deployment

The LGM-30A Minuteman-I was first test-fired on 1 February 1961, and entered into the Strategic Air Command’s arsenal in 1962, at Malmstrom Air Force Base, Montana; the “improved” LGM-30B became operational at Ellsworth Air Force Base, South Dakota, Minot Air Force Base, North Dakota, F.E. Warren Air Force Base, Wyoming, and Whiteman Air Force Base, Missouri in 1963. All 800 Minuteman-I missiles were delivered by June 1965. Each of the bases had 150 missiles emplaced. Malmstrom AFB had 150 of the Minuteman I and about five years later added 50 of the Minuteman II similar to those installed at Grand Forks AFB, ND.

Guidance

The Minuteman-I Autonetics D-17 flight computer used a rotating air bearing magnetic disk holding 2,560 “cold-stored” words in 20 tracks (write heads disabled after program fill) of 24 bits each and one alterable track of 128 words. The time for a D-17 disk revolution was 10 ms. The D-17 also used a number of short loops for faster access of intermediate results storage. The D-17 computational minor cycle was three disk revolutions or 30 ms. During that time all recurring computations were performed. For ground operations the inertial platform was aligned and gyro correction rates updated. During flight, filtered command outputs were sent each minor cycle to the engine nozzles. Unlike modern computers, which use descendants of that technology for secondary storage on hard disk, the disk was the active computer memory. The disk storage was considered hardened to radiation from nearby nuclear explosions, making it an ideal storage medium. To improve computational speed, the D-17 borrowed an instruction look-ahead feature from the Autonetics-built Field Artillery Data Computer (M18 FADAC) that permitted simple instruction execution every word time.

The D-17B and the D-37C guidance and control computers were integral components of the Minuteman I and II missiles, respectively, which formed a part of the United States ICBM arsenal. The Minuteman III missiles, which use D-37D computers, complete the 1000 missile deployment of this system. The initial cost of these computers ranges from about $139,000 (D-37C) to $250,000 (D-17B).

Minuteman-II (LGM-30F)

1. See also W56 Warhead
2. See also W62 Warhead

The LGM-30F Minuteman-II was an improved version of the Minuteman-I missile. Development on the Minuteman-II began in 1962 as the Minuteman-Is entered the Strategic Air Command’s nuclear force. Minuteman-II production and deployment began in 1965 and completed in 1967. It had an increased range, payload and guidance system with better azimuthal coverage, providing military planners with better accuracy and a wider range of targets. Some missiles also carried penetration aids, allowing higher probability of kill against Moscow’s antiballistic missile system. The payload consisted of a single Mk-11C reentry vehicle containing a W56 nuclear warhead with a yield of 1.2 megatons of TNT (5 PJ). Performance improvements realized in Minuteman-II include greater range, increased throw weight, improved accuracy and reliability, multiple target selection, and greater penetration capability.

• The major new features provided by Minuteman-II were:
  • An improved first-stage motor to increase reliability.
  • A new-technology, single, fixed nozzle with liquid injection thrust vector control (TVC) on a larger second stage motor to increase missile range. Additional motor improvements to increase reliability.
  • An improved guidance system, incorporating semiconductor integrated circuits and miniaturized discrete electronic parts. Minuteman-II was the first program to make a major commitment to these new devices. Their use made possible multiple target selection, greater accuracy and reliability, a reduction in the overall size and weight of the guidance system, and an increase in the survivability of the guidance system in a nuclear environment.
  • A penetration aids system to camouflage the warhead during its reentry into an enemy environment.
  • A larger warhead in the reentry vehicle (RV) to increase kill probability.

System modernization was concentrated on launch facilities and command and control facilities. This provided decreased reaction time and increased survivability when under nuclear attack. Final changes to the system were performed to increase compatibility with the LGM-118A, as these latter missiles were introduced into modified Minuteman silos.

The Minuteman-II program was economically important to the development of integrated circuits. It was the first mass-produced system to use a computer constructed from integrated circuits (the Autonetics D-37C), and used most of the production of such circuits from 1962 through 1967. The Minuteman-II integrated circuits were diode-transistor logic and diode logic made by Texas Instruments. The other major customer of early integrated circuits was the Apollo Guidance Computer, which had similar weight and ruggedness constraints. The Apollo integrated circuits were resistor-transistor logic made by Fairchild Semiconductor. The Minuteman-II flight computer continued to use rotating magnetic disk for primary storage.

Minuteman-III (LGM-30G)

The LGM-30G Minuteman-III program started in 1966, and included several improvements that distinguish it from the LGM-30F Minuteman-II. Most modifications related to the final stage and reentry system (RS), with the third stage improved with a new fluid-injected motor, giving finer control than the previous four nozzle system.Performance improvements realized in Minuteman-III include increased flexibility in reentry vehicle (RV) and penetration aids deployment, increased survivability after a nuclear attack, and increased payload capacity.

• Minuteman-III contains the following distinguishing features:
  • A larger third-stage motor to increase range.
  • A fixed nozzle with a liquid injection TVC system on the new third-stage motor (similar to the second-stage Minuteman-II nozzle) to increase range.
  • A RS capable of deploying penetration aids (chaff) and up to three RVs to increase payload delivery.
  • An added post-boost propulsion system (the Propulsion System Rocket Engine, or PSRE) to increase range and maneuver the RS. This maneuverability allows the RS to be positioned at selected locations prior to the deployment of its RVs and penetration aids.
  • An improved flight computer (Autonetics D37D) with larger disk memory and enhanced capability.

A Honeywell HDC-701 flight computer which employs NDRO (non-destructive read out) plated wire memory instead of rotating magnetic disk for primary storage was developed as a backup for the D37D, but was never adopted. The D37D remained the flight computer for the Minuteman III until the guidance system was replaced on the Guidance Replacement Program (GRP).

The Guidance Replacement Program (GRP), initiated in 1993, flight computer uses radiation-resistant semiconductor RAM.

[[Image:Minuteman III MIRV path.svg|center|thumb|600px|Minuteman-III MIRV launch sequence:

1. The missile launches out of its silo by firing its 1st stage boost motor (A).

2. About 60 seconds after launch, the 1st stage drops off and the 2nd stage motor (B) ignites. The missile shroud is ejected.

3. About 120 seconds after launch, the 3rd stage motor (C) ignites and separates from the 2nd stage.

4. About 180 seconds after launch, 3rd stage thrust terminates and the Post-Boost Vehicle (D) separates from the rocket.

5. The Post-Boost Vehicle maneuvers itself and prepares for re-entry vehicle (RV) deployment.

6. The RVs, as well as decoys and chaff, are deployed during backaway.

7. The RVs and chaff re-enter the atmosphere at high speeds and are armed in flight.

8. The nuclear warheads detonate, either as air bursts or ground bursts.]]

Current Deployment

A total of 450 LGM-30G missiles are emplaced at F.E. Warren Air Force Base, Wyoming (90th Missile Wing), Minot Air Force Base, North Dakota (91st Missile Wing), and Malmstrom Air Force Base, Montana (341st Missile Wing). All Minuteman I and II have been retired.

Testing

Minuteman III missiles are regularly tested with launches from Vandenberg Air Force Base. The most recent launch, successfully targeting the Kwajalein Atoll 4,200 miles downrange with three unarmed re-entry vehicles, was conducted 2009-06-29.

Related Programs

• Remote Visual Assessment (RVA) - provides real-time video to ICBM security forces. This video allows forces to respond to threats more quickly, and with appropriate force and situational awareness. RVA will also cut down on “wear and tear” of equipment and personnel, often caused from responding to false alarm threats.
• Rivet MILE — Minuteman Integrated Life Extension. Included IMPSS security system upgrade.
• Rivet ADD — Modification of Minuteman-II launch facilities to hold MM III missiles
• Missile Defense - Kinetic Energy Interceptor (KEI, “space bullet”)
• LONG LIFE - launch of Minuteman from 'live' launch facility w/7 sec of fuel
• BUSY SENTRY - Strategic Air Command exercise for intercontinental ballistic missile units.
• BUSY SURVEY II - Strategic Air Command Strategic Integrated Operational Plan (SIOP) 4D missile training assistance program
• BUSY USHER - Strategic Air Command launch of No. 13 LF-02 missile MK-1 Minuteman II
• BUTTON UP - Strategic Air Command security system reset procedures used during Minuteman facility wind down
• DUST HARDNESS - A modification improvement to Minuteman III approved for service use in 1972
• GIANT PATRIOT - The code name describes an operational base launch program of test flights of Minuteman II missiles. The program was terminated by Congress in July 1974
• GIANT PLOW - An Air Force Minuteman launcher closure test program
• GIANT PROFIT - A Minuteman modified operational missile test plan
• GIGANTIC CHARGE - Program to notify NORAD of all or part of strategic integrated operational plan (SIOP) targeting for Minuteman
• GIN PLAYER - Strategic Air Command tests of Minuteman missile for identification and execution
• HAVE LEAP - A Space and Missile Test Center support of Minuteman III program
• MIDDLE GUST – An Air Force test conducted at Crowley, CO involving a simulated nuclear overblast of a Minuteman silo
• OLD FOX - Minuteman III flight tests
• OLYMPIC ARENA III - Strategic Air Command missile competition of all nine operational missile units
• OLYMPIC EVENT - A Minuteman III nuclear operational systems test
• OLYMPIC PLAY - A Strategic Air Command missiles and operational ground equipment program for EWO missions
• OLYMPIC TRIALS - A program to represent a series of launches having common objectives
• PACER GALAXY - Support of Minuteman force modification program
• PAVE PEPPER - An Air Force SAMSO (Space & Missile Systems Organization) project to decrease the size of the Minuteman III warheads and allow for more to be launched by one Minuteman.
• RIVET SAVE - A Minuteman crew sleep program modification to reduce personnel number
• SABER SAFE - Minuteman pre-launch survivability program
• SABER SECURE - A Minuteman rebasing program
• SENTINEL ALLOY - Land gravity surveys in support of the Minuteman system, cancelled
• UPGRADE SILO - A modification improvement program for Minuteman III

Influences

The author Thomas Pynchon worked as a technical writer for the field support unit for the Minuteman missile, something that is probably reflected in the narrative of his novels The Crying of Lot 49 and Gravity’s Rainbow.

The Minuteman Missile National Historic Site in South Dakota preserves a Launch Control Facility (D-01) and a launch facility (D-09) under the control of the National Park Service.

Appearances in Media

Footage of Minuteman III ICBM test launches have been featured in several theatrical films and television movies where missile launch footage is needed. The Department of Defense film released for use was mainly drawn from Vandenberg Air Force Base test shots in 1966, including from a "salvo launch" (more than one ICBM launched simultaneously).

Theatrically-released films using the footage include (most notably), the 1978 film Superman (which features the "twin shot"), and more extensively, the 1977 nuclear war film Damnation Alley. The made for TV film The Day After also features the same footage, although the first stage of flight is completed via special effects. Terminator 3 uses computer generated images of Minuteman missiles launching from the Plains on Judgment Day. Also features in Eagle Strike, by Anthony Horowitz, in which fictional power-crazed multimillionaire Damian Cray orders their release from Air Force One.

Other Roles

Mobile Minuteman program

While the silo-based Minuteman was in development, the United States Air Force released details about a rail-based counterpart. On October 12, 1959, details on the system, called the “Mobile Minuteman,” were released to the public. The system used the United States railroad network to help increase the system's survivability during nuclear attack. A performance test, code named Operation Big Star, was conducted from June 20 to August 27, 1960 at Hill Air Force Base, Utah. The United States Air Force then activated the 4062nd Mobile Missile Wing on December 1, 1960. The wing was to have three missile train squadrons, each with ten trains and each train carrying three missiles (30 missiles per squadron). Lack of support by the Kennedy Administration killed the Mobile Minuteman Program; on December 1, 1961, the Department of Defense deleted the three mobile missile squadrons from its budget. The USAF officially deactivated the 4062nd Mobile Missile Wing on February 20, 1962.

The thoughts of a rail-based missile system were kept alive through the LGM-118A Peacekeeper Rail Garrison and the Soviet Union’s SS-24 Scalpel rail-based ICBM.

Emergency Rocket Communications System (ERCS)

An additional part of the National Command Authority communication relay system was called the Emergency Rocket Communication System (ERCS). Specially designed rockets called BLUE SCOUT carried radio-transmitting payloads high above the continental United States, to relay messages to units within line-of-sight. In the event of a nuclear attack, ERCS payloads would relay preprogrammed messages giving the “go-order” to SAC units. BLUE SCOUT (sometimes called RED SPY) launch sites were located at Wisner, West Point and Tekamah, Nebraska. These locations were vital for ERCS effectiveness due to their centralized position in the US, within range of all missile complexes. Later ERCS configurations were placed on the tops of modified Minuteman-II ICBMs (LGM-30Fs) under the control of the 510th Strategic Missile Squadron located at Whiteman Air Force Base, Missouri.

Satellite launching role

The U.S. Air Force has considered using some decommissioned Minuteman missiles in a satellite launching role. These missiles would be stored in silos, for launch upon short notice. The payload would be variable, and would have the ability to be replaced quickly. This would allow a surge capability in times of emergency.

Ground and Air Launch Targets

L-3 Communications is currently using SR-19 SRBs, Minuteman II Second Stage Solid Rocket Boosters, as delivery vehicles for a range of different re-entry vehicles as targets for the THAAD and ASIP interceptor missile programs as well as radar testing.

Minuteman chronology

Photo Gallery

Image:Minuteman comparison.png|Family of Minuteman missilesImage:Minuteman12.png|Minuteman-I Line DrawingImage:Minuteman3.png|Minuteman III Line DrawingImage:Minuteman II.jpg|Minuteman-II launchImage: Mark 5 warhead.png|Mark 5 Re-entry vehicle for Minuteman IAImage: Minuteman I first test flight.png|First test flight of MM IImage: Minuteman I launch color.png|Color Photo of MM IImage: Minuteman I launch mockup.png|Mockup MM on test standImage: Minuteman I static test.png|Static firing of downstageImage: Minuteman I test inspection.png|Inspection of MM IImage: Minuteman I test sequence.png|Test SequenceImage: Minuteman I test silo.png|Test SiloImage: Minuteman I test silos at Edwards AFB.png|Silos at Edwards AFBImage: Minuteman I transport.png|MM I being transported by railImage: Proposed Minuteman basing.png|Proposed Minuteman Basing circa 1962Image: Mobile Minuteman Mockup.png|Mobile Minuteman MockupImage: Mobile Minuteman train.png|Mobile Minuteman Train

See also

References

• The Boeing Corporation (1973) Technical Order 21M-LGM30G-1-1: Minuteman Weapon System Description. Seattle: Boeing Aerospace. Contains basic weapon descriptions.

• The Boeing Corporation (1973) Technical Order 21M-LGM30G-1-22: Minuteman Weapon System Operations. Seattle: Boeing Aerospace. Operators Manual.

• The Boeing Corporation (1994) Technical Order 21M-LGM30G-2-1-7: Organizational Maintenance Control, Minuteman Weapon System. Seattle: Boeing Aerospace. Operators Manual.

• Lloyd, A. (2000) Cold War Legacy: A Tribute to the Strategic Air Command: 1946-1992. New York: Turner Publishing.

• Neal, Roy. (1962) Ace in the Hole: The Story of the Minuteman Missile. New York: Doubleday & Company. Library of Congress Catalog Card Number 62-7665.

• TRW Systems. (2001) Minuteman Weapon System History and Description. http://www.nukestrat.com/us/afn/Minuteman.pdf; Contains system history and basic descriptions.

• Zuckerman, E. (1984) The Day after World War III. New York: Viking Press.

External links

• Minuteman Information Site
• Strategic-Air-Command.com Minuteman Missile History
• http://www.stratcom.mil/FactSheetshtml/ballistic_missiles.htm
• http://www.designation-systems.net/dusrm/m-30.htm
• http://nuclearweaponarchive.org/Usa/Weapons/Mmiii.html
• Minuteman Missile National Historic Site
• U. S. Air Force Fact Sheet - LGM-30
• PROCEEDINGS OF THE SECOND MEETING of the MINUTEMAN COMPUTER USERS GROUP
• Video of an LGM-30 Minuteman launch
• The 6555th's Role in the Development of Ballistic Missiles, The MINUTEMAN Ballistic Missile Test Program