LGM-30 MinutemanFrom Wikipedia, the free encyclopedia

The LGM-30 Minuteman is a United States nuclear missile, a land-basedintercontinental ballistic missile (ICBM). As of 2006 it is the only land-based ICBM inservice in the United States. It is complemented by the sea-launched Trident missileICBM (SLBM) and by nuclear weapons carried by long-range strategic bombers; seecurrent status of United States nuclear weapons.

The L indicates that the missile is silo-launched; the G indicates that it is designed toattack surface targets; and the M indicates that it is a guided missile.

The name "Minuteman" comes from the Revolutionary War's Minutemen.

Current model

The current Minuteman force consists of 500 Minuteman IIIs in missile silos around F.E. Warren AirForce Base, Wyoming, Malmstrom Air Force Base, Montana, and Minot Air Force Base, North Dakota.

It is a guided missile, with three solid-fuel stages, and in addition, in the post-boost stage ("bus"), aliquid-fuel propulsion system rocket engine used to fine-tune the trajectory of the reentry vehicle and/ordispense individual warheads to separate targets across a broad area. The missile has a gimballed inertialguidance system.

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

With START II’s ban on multiple independently targetable reentry vehicles (MIRVs) now a dead letter,earlier plans to reduce the number of warheads per missile to one have been revised: the United States isnow considering keeping 800 warheads on the Minuteman force.

The Minuteman III missile entered service in 1970, with weapon systems upgrades included during theproduction run from 1970 to 1978 to increase accuracy and payload capacity. 1998 USAF plans are tooperate it until 2025.

The LGM-118A Peacekeeper MX ICBM, which was meant to replace the Minuteman, was due to beretired by 2005. The Peacekeeper suffered from controversy over various mobile basing schemes, butthe original Peacekeeper basing plan included being deployed on railroad cars.

Guidance Replacement Program (GRP)

The Guidance Replacement Program (GRP) replaces the NS20A Missile Guidance Set with the NS50AMissile Guidance Set. The newer system extends the service life of the Minuteman missile beyond theyear 2020 by replacing aging parts and assemblies with current, high reliability technology whilemaintaining the current accuracy performance.

Propulsion Replacement Program (PRP)

The Propulsion Replacement Program extends the life, maintains the performance, and improves thereliability of the operational ICBM force by replacing the old solid propellant boosters (downstages)with new "environmentally friendly" booster.

Single Reentry Vehicle (SRV)

The Single Reentry Vehicle (SRV) modification allows the United States ICBM force to abide bySTART treaty requirements by reconfiguring Minuteman III missiles from three re-entry vehicles downto one.

Safety Enhanced Reentry Vehicle (SERV)

Beginning in 2006, Mk-21/W87 RVs from the deactivated LGM-118A Peacekeeper missile will beplaced on the Minuteman III force under the Safety Enhanced Reentry Vehicle (SERV) program. Theolder W78 currently used is not equipped with important safety features. In addition to adding additionalsafety features into at least a portion of the future Minuteman III force, the decision to transfer W87 ontothe missile is based on two features that will improve the targeting capabilities of the weapon: morefuzing options which will allow for greater targeting flexibility and the most accurate reentry vehicleavailable which provide a greater probability of damage.

Organization

The basic tactical unit of a Minuteman wing is the squadron, consisting of five flights. Each flightconsists of ten unmanned launch facilities (LFs) which are remotely controlled by a manned launchcontrol center (LCC). The five flights are interconnected and status from any LF may be monitored byany of the five LCCs. Each LF is located at least three nautical miles (5.6 km) from any LCC. Controldoes not extend outside the squadron (i.e. The 319th missile squadron's five LCCs cannot control the320th Missile Squadron's 50 LFs). Each Minuteman wing is assisted logistically by a nearby MissileSupport Base (MSB).

Operator

United States: The United States Air Force is the only operator of the Minuteman III, with threeoperational wings and one test squadron operating the LGM-30G:

526th ICBM Systems Wing — Hill AFB, Utah 576th Flight Test Squadron — Vandenberg AFB, California — "Top Hand" Wing One: 341st Space Wing — Malmstrom AFB, Montana — "Grizzlies"

o 10th Missile Squadron — "First Aces"o 12th Missile Squadron — "Red Dawgs"o 490th Missile Squadron — "Farsiders"o 564th Missile Squadron — "Deuce"

Wing Two: 44th Strategic Missile Wing — Ellsworth AFB, South Dakota —"Black Hills Bandits" — Deactivated

o 66th Missile Squadrono 67th Missile Squadrono 68th Missile Squadron

Wing Three: 91st Space Wing — Minot AFB, North Dakota — "Roughriders"o 740th Missile Squadron — "Vulgar Vultures"o 741st Missile Squadron — "Gravelhaulers"o 742nd Missile Squadron — "Wolf Pack"

Wing Four: 351st Strategic Missile Wing — Whiteman AFB, Missouri —Deactivated

o 508th Missile Squadrono 509th Missile Squadron

o 510th Missile Squadron Wing Five: 90th Space Wing — F.E. Warren AFB, Wyoming

o 319th Missile Squadron — "Screaming Eagles"o 320th Missile Squadrono 321st Missile Squadron — "Frontier Warriors"

Wing Six: 321st Strategic Missile Wing — Grand Forks AFB, North Dakota —Deactivated

o 446th Missile Squadrono 447th Missile Squadrono 448th Missile Squadron

History

Minuteman I missile

The Minuteman I and II were in service from 1960 until 1997. The Minuteman III was first deployedin 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, anda digital flight computer. This computer was one of the very first recognizably modern embeddedsystems.

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

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

A digital computer was essential to obtain the accuracy gains that kept this weapon effective throughoutthe 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 beupdated and loaded into the missiles to make them ever more accurate by having them compensate forthese sources of gravity. Another gain that persuaded program managers to accept the risk of thecomputer was that the computer could also be used to test the missile. This saved a large amount ofweight in cables and connectors.

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

Autonetics D-17 guidance computer from a Minuteman I missile.

The LGM-30A Minuteman I entered into the Strategic Air Command's arsenal in 1962, at MalmstromAFB, Montana; the 'improved' LGM-30B became operational at Ellsworth AFB, South Dakota, MinotAFB, North Dakota, F.E. Warren AFB, Wyoming, and Whiteman AFB, Missouri in 1963. All 800Minuteman I missiles were delivered by June 1965. Each of the bases had 150 missiles emplaced, exceptfor F.E. Warren AFB, which had 200 missiles.

The Minuteman I Autonetics D-17 flight computer used a rotating air bearing magnetic disk holding2,560 "cold-stored" words in 20 tracks (write heads disabled after program fill) of 24 bits each and onealterable track of 128 words. The time for a D-17 disk revolution was 10 ms. The D-17 also used anumber of short loops for faster access of intermediate results storage. The D-17 computational minorcycle 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 activecomputer memory. The disk storage was considered hard to radiation from nearby nuclear explosions,making it an ideal storage medium. To improve computational speed, the D-17 borrowed an instructionlook-ahead feature from the Autonetics-built Field Artillery Data Computer (FADAC) that permittedsimple instruction execution every word time.

Minuteman II (LGM-30F)

Side-view of Minuteman I and II ICBM

Minuteman II launch

The LGM-30F Minuteman II was an improved version of the Minuteman I missile. Development on theMinuteman II began in 1962 as the Minuteman I's entered the Strategic Air Command's nuclear force.Minuteman II production and deployment began in 1965 and completed in 1967. It had an increasedrange, payload and guidance system with better azimuthal coverage, providing military planners withbetter accuracy and a wider range of targets. Some missiles also carried penetration aids, allowinghigher probability of kill against Moscow's ABM system. The payload consisted of a single Mk 11Creentry 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:o An improved first-stage motor to increase reliability.o 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.

o An improved guidance system, incorporating semiconductor integratedcircuits and miniaturized discrete electronic parts. Minuteman II was thefirst program to make a major commitment to these new devices. Theiruse made possible multiple target selection, greater accuracy andreliability, a reduction in the overall size and weight of the guidancesystem, and an increase in the survivability of the guidance system in anuclear environment.

o A penetration aids system to camouflage the warhead during its reentryinto an enemy environment.

o A larger warhead in the reentry vehicle (RV) to increase kill probability.

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

The Minuteman II program was economically crucial to the development of integrated circuits. It wasthe first mass-produced system to use a computer constructed from integrated circuits, and used most ofthe production of such circuits from 1962 through 1967. The other major customer of these circuits wasthe Apollo Guidance Computer, which had similar weight and ruggedness constraints. The MinutemanII flight computer continued to use rotating magnetic disk for primary storage.

A total of 450 LGM-30F missiles were emplaced at Ellsworth AFB, South Dakota (44th StrategicMissile Wing), Grand Forks AFB, North Dakota (321st Strategic Missile Wing), Malmstrom AFB,Montana (341st Strategic Missile Wing), and Whiteman AFB, Missouri (351st Strategic Missile Wing).

Minuteman III (LGM-30G)

Side-view of Minuteman III ICBM

Honeywell HDC-701 Guidance computer from a Minuteman III missile, on display at the National Air and SpaceMuseum in Washington, D.C.

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

Minuteman III contains the following distinguishing features:o A larger third-stage motor to increase range.o 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.o A RS capable of deploying penetration aids (chaff) and up to three RVs to

increase payload delivery.o An added post-boost propulsion system (the Propulsion System Rocket

Engine, or PSRE) to increase range and maneuver the RS. Thismaneuverability allows the RS to be positioned at selected locations priorto the deployment of its RVs and penetration aids.

o Improved electronics in the guidance system to provide more computermemory and greater accuracy, and to reduce vulnerability to a nuclearenvironment.

The Minuteman III Honeywell HDC-701 flight computer used NDRO (non-destructive read out) platedwire memory instead of rotating magnetic disk for primary storage.

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

Weapon system programs

Rivet MILE — Minuteman Life Extension Rivet ADD — Modification of MM II launch facilities to hold MM III missiles

Influences

The author Thomas Pynchon worked as a technical writer for the field support unit for the Minutemanmissile, something that is probably reflected in the narrative of his novels The Crying of Lot 49 andGravity's Rainbow.[citation needed]

The Minuteman Missile National Historic Site in South Dakota has recently been created. It preserves aLaunch Control Facility and a missile silo complex under the control of the National Park Service.

Mobile Minuteman program

While the silo-based Minuteman was in development, the United States Air Force released details abouta rail-based counterpart. On 12 Oct 1959, details on the system, called the 'Mobile Minuteman', werereleased to the public. The system used the United States railroad network to help increase the system'ssurvivability during nuclear attack. A performance test, code named Operation Big Star, was conducted

from 20 June to 27 August 1960 at Hill AFB, Utah. The United States Air Force then activated the4062nd Mobile Missile Wing on 1 Dec 1960. The wing was to have three missile train squadrons, eachwith ten trains and each train carrying three missiles (30 missiles per squadron). Lack of support by theKennedy Administration killed the Mobile Minuteman Program; on 1 Dec 1961, the Department ofDefense deleted the three mobile missile squadrons from its budget. The USAF officially deactivated the4062nd Mobile Missile Wing on 20 Feb 1962.

The idea for a rail-based missile system was kept alive through the LGM-118A Peacekeeper RailGarrison 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 theemergency rocket communication system (ERCS). Specially designed rockets called BLUE SCOUTcarried radio-transmitting payloads high above the continental United States, to relay messages to unitswithin line-of-sight. In the event of a nuclear attack, ERCS payloads would relay preprogrammedmessages giving the ‘go-order’ to SAC units. BLUE SCOUT launch sites were located at Wisner, WestPoint and Tekamah, Nebraska. These locations were vital for ERCS effectiveness due to theircentralized position in the US, within range of all missile complexes. Later ERCS configurations wereplaced on the tops of modified Minuteman II ICBMs (LGM-30Fs) under the control of the 510thStrategic Missile Squadron located at Whiteman AFB, Missouri.

Satellite launching role

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

Minuteman chronology

1956o Von Neumann Committee approved Ballistic Missile feasibility programo R&D programs and contracts authorized

1957o ICBM improvements studies startedo Minuteman configuration studies started

1958o Minuteman R&D program authorized

1959o First R&D firing from silo - inert second and third stage

1960o First contract for operational wing facilities at Wing Io Missile production

1961

o First all-up missile launch from pad at Eastern Test Rangeo First missile launch from silo at Eastern Test Range

1962o First missile launch from Western Test Rangeo Minuteman I operational flight turnover at Wing I

1963o First wing turnover at Wing I, Wing II turnovero Force Mod program approvedo First motor static test firing to verify reliability

1964o Wing III and IV turnovero New features approvedo Minuteman II flight testo GIANT BOOST

1965o Wing V turnovero Vulnerability improvementso Minuteman fully operational at Wing II, III

1966o Wing IV turnovero Minuteman III approvalo Aging surveillance program initiatedo Minuteman II operational at Wing VIo ERCS deployed

1967o Squadron 20 turnovero Force Mod at Wing IV

1968o Hard rock silo program startedo First Minuteman III R&D flight

1969o Force Mod rate decreaseo Force Mod at Wing I completeo Service Star testing began for RSs

1970o First Minuteman III at Wing III (Hotel Flight/H-02)o Upgrade silo and CDB programs startedo First MOM test at Wing VI

1971o Minuteman III dust program startedo Force Mod at Wing III completed

Minuteman III on display at Air Force Museum

1972o Minuteman III deployed at Wing VIo First dust hardened Minuteman III deployed at Wing VIo Minuteman ordnance service life analysis program developedo Responsibility for service life testing transferred to Ogden Air Logistics

Center (OO-ALC), Hill AFB, Utah 1973

o Upgrade silo and CDB IOC at Wing Vo Force Mod and upgrade silo completed at Wing IIo Last MOM at Wing III

1974o Full Force upgrade silo approvedo MK12A and Pave Pepper programs startedo SSAS was deployed for Minuteman II

1975o Upgrade silo and CDB completed at Wing Vo Upgrade silo and CDB start at Wing IIIo Simulated electronics launch Minuteman (SELM) program startedo Minuteman bench test program concept developed by OO-ALCo Minuteman III fully deployedo Minuteman program management responsibility transfer (PMRT)

1976

o Upgrade silo and CDB completed at Wing IIIo Upgrade silo and CDB completed at Wing VIo Long range service life analysis performed for propulsion systemo Hybrid explicit implemented for Minuteman IIIo Minuteman II MGS vibration test program initiatedo New calibration schedule implemented to correct MGS startup transientso Minuteman II Stage 3 lot 16 motor igniters replaced

1977o Minuteman III missile production terminatedo Inertial performance data began to be collected for guidance system fault

isolationo Began implementation of ILCS at Minuteman II wings

1978o GIP implemented at Minuteman IIIo Thrust termination port investigation began

1979o Minuteman II Stage 2 motor remanufacturing program began to correct

degraded liner/Minuteman III Stage 3 degraded liner investigationinitiated

o USAF advisory board recommended that carbon-carbon nose tips bedeveloped for MK12 RVs

1980o Upgrade silo and CDB completed at Wing VIo Minuteman II accuracy/reliability investigation conductedo VRSA replacement design startedo Diagnostic data package hardware delivered to provide re-entry/separation

data for Minuteman II flights 1981

o MGS electronics investigation completedo Accuracy, Reliability, Supportability Improvement Program (ARSIP)

program began 1982

o Minuteman III guidance upgrade program implementedo MK12A re-entry vehicle FOCo Special operational test program began - Minuteman IIo Hardness critical items identified and procured

1983o Minuteman III MGS vibration test program initiatedo Special operational test program complete - accuracy improvements

verified 1984

o Minuteman Extended Survivable Power IOCo GUP implemented for Minuteman III

1985o Rivet MILE (MInuteman Life Extension) began

1986

o LGM-118A Peacekeeper deployment initiated 1987

o Integrated Nuclear Effects Assessment (INEA)o ARSIP implemented for Minuteman IIo Piece-parts manufacturing for diminished manufacturing sourceso Rivet MILE began Improved Minuteman Physical Security System

(IMPSS) installation 1988

o Minuteman III Stage 2 washout/Stage 3 replacemento Comprehensive reliability investigations conducted

1989o Rapid Execution and Combat Targeting (REACT) program initiatedo Rocket Motor Transporter replacemento Code Change Verifier replacemento Transporter-Erector replacement

1990 1991

o Minuteman II removed from SIOP 1992

o Minuteman II deactivation initiatedo MESP discontinuedo Rivet MILE completes IMPSS installationo SRV Program initiatedo Rivet ADD initiatedo Missile Transporter replacemento Missile Transporter (PT III) replacement

1993o GRP contract awarded

1994o PRP initial contracts awarded

1995o REACT consoles begin deploymento Minuteman II deactivation completeo BRAC decision to close Wing VI by 1998

1996o REACT deployment complete

1998o Wing VI deactivation completeo Wing VI Minuteman III's moved to Wing Io AF awards ICBM Prime contract to TRW team for ICBM engineering

1999o First NS-50 MGS deployed

2000 2001

o PRP deployment initiated

References

Gibson, James N. Nuclear Weapons of the United States. Atglen, Pennsylvania:Schiffer Publishing Ltd, 1996. ISBN 0764300636. Encyclopedia; contains historyof Minuteman ICBM.

The Boeing Corporation (1973) Technical Order 21M-LGM30G-1-1: MinutemanWeapon System Description. Seattle: Boeing Aerospace. Contains basic weapondescriptions.

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

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. NewYork: 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 andbasic descriptions.

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