LGM-30 Minuteman

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LGM-30 Minuteman
Minuteman3launch.jpg
TypeIntercontinental ballistic missile
Place of originUnited States
Service history
In service1962 (Minuteman I), 1965 (Minuteman II), 1970 (Minuteman III)
Used byUnited States
Production history
ManufacturerBoeing
Unit cost$7,000,000
Specifications
Weight78,000 lb (35,300 kg)
Length59 ft 9.5 in (18.2 m)
Diameter5 ft 6 in (1.7 m) (1st stage)
WarheadNuclear: W62, W78, or (2006–) W87
Detonation
mechanism
Air Burst or Contact (Surface)

EngineThree solid-propellant rocket motors; first stage: Thiokol TU-122 (M-55); second stage: Aerojet-General SR-19-AJ-1; third stage: Aerojet/Thiokol SR73-AJ/TC-1
Operational
range
8,100 (Exact is Classified)  miles (13,000 km)
Flight altitude700 miles (1,120 kilometers)
SpeedApproximately 15,000 mph (Mach 23, or 24,100 km/h, or 7 km/s) (terminal phase)
Guidance
system
Inertial
Accuracy200 m CEP
Launch
platform
Missile Silo(MLCC)
 
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LGM-30 Minuteman
Minuteman3launch.jpg
TypeIntercontinental ballistic missile
Place of originUnited States
Service history
In service1962 (Minuteman I), 1965 (Minuteman II), 1970 (Minuteman III)
Used byUnited States
Production history
ManufacturerBoeing
Unit cost$7,000,000
Specifications
Weight78,000 lb (35,300 kg)
Length59 ft 9.5 in (18.2 m)
Diameter5 ft 6 in (1.7 m) (1st stage)
WarheadNuclear: W62, W78, or (2006–) W87
Detonation
mechanism
Air Burst or Contact (Surface)

EngineThree solid-propellant rocket motors; first stage: Thiokol TU-122 (M-55); second stage: Aerojet-General SR-19-AJ-1; third stage: Aerojet/Thiokol SR73-AJ/TC-1
Operational
range
8,100 (Exact is Classified)  miles (13,000 km)
Flight altitude700 miles (1,120 kilometers)
SpeedApproximately 15,000 mph (Mach 23, or 24,100 km/h, or 7 km/s) (terminal phase)
Guidance
system
Inertial
Accuracy200 m CEP
Launch
platform
Missile Silo(MLCC)

The LGM-30 Minuteman is a United States land-based intercontinental ballistic missile (ICBM), in service with the United States Air Force Global Strike Command. As of 2010, the LGM-30G Minuteman III version is the only land-based ICBM in service in the United States. It is one component of the US nuclear triad—the other two parts of the triad being the Trident submarine-launched ballistic missile (SLBM), and nuclear weapons carried by long-range strategic bombers. Each missile carries up to three nuclear warheads, which have a yield in the range of 300 to 500 kilotons. The Minuteman was the first MIRV-capable missile.

The letter “L” in “LGM” 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.[1]

The name “Minuteman” comes from the Revolutionary War’s Minutemen. It also refers to its quick reaction time; the missile can be launched within minutes after the receipt of a valid launch order.[2][3] The Air Force plans to keep the missile in service until at least 2030.[4][5]

The current US force consists of 450 Minuteman-III missiles[6] in missile silos around Malmstrom AFB, Montana; Minot AFB, North Dakota; and F.E. Warren AFB, Wyoming.[1]

History[edit]

Minuteman I missile

The previous versions, Minuteman-I and Minuteman-II, were in service from 1962 until 1997.

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 earlier ICBMs, which used liquid rocket propellants.

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)[edit]

See also W56 Warhead
Autonetics D-17 guidance computer from a Minuteman I missile.

Deployment[edit]

The LGM-30A Minuteman-I was first test-fired on 1 February 1961,[7] and entered into the Strategic Air Command’s arsenal in 1962, at Malmstrom Air Force Base, Montana[8] ; 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. F.E. Warren AFB had 200 of the Minuteman 1B's. 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[edit]

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 ranged from about $139,000 (D-37C) to $250,000 (D-17B).

Minuteman-II (LGM-30F)[edit]

See also W56 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, a greater throw weight 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 anti-ballistic 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).

The major new features provided by Minuteman-II were:

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 expected LGM-118A Peacekeeper. These newer missiles were later deployed into modified Minuteman silos.

The Minuteman-II program was the first mass-produced system to use a computer constructed from integrated circuits (the Autonetics D-37C). 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 disks for primary storage.

Minuteman-III (LGM-30G): the current model [edit]

Side view of Minuteman-III ICBM
Airmen work on a Minuteman III’s Multiple Independently-targetable Re-entry Vehicle (MIRV) system. Current missiles carry a single warhead.

The LGM-30G Minuteman-III program started in 1966, and included several improvements over the previous versions. It was first deployed in 1970. Most modifications related to the final stage and reentry system (RS). The final (third) stage was 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.[1] The missile retains a gimballed inertial guidance system.

Minuteman-III originally contained the following distinguishing features:

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 (E) 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 initiate, either as air bursts or ground bursts.

The existing Minuteman III have been further improved over the decades in service, with more than $7 billion spent in the last decade to upgrade the 450 missiles.[11]

Guidance Replacement Program (GRP)[edit]

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 2030 by replacing aging parts and assemblies with current, high reliability technology while maintaining the current accuracy performance. The replacement program was completed 25 February 2008.[4]

Propulsion Replacement Program (PRP)[edit]

Beginning in 1998 and continuing through 2009,[12] the Propulsion Replacement Program extends the life and maintains the performance by replacing the old solid propellant boosters (downstages).

Single Reentry Vehicle (SRV)[edit]

The Single Reentry Vehicle (SRV) modification enabled the United States ICBM force to abide by the now-vacated START II treaty requirements by reconfiguring Minuteman-III missiles from three reentry vehicles down to one. Though it was eventually ratified by both parties, START II never entered into force and was essentially superseded by follow-on agreements such as SORT and New START, which do not limit MIRV capability.

Safety Enhanced Reentry Vehicle (SERV)[edit]

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 implementing these safety features in 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-modded Minuteman III was put on alert status at FE Warren AFB, Wyoming, in 2006.[citation needed]

Current and future deployment[edit]

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 2008, the USAF plans to operate it until at least 2030.[4][5]

The LGM-118A Peacekeeper (MX) ICBM, which was to have replaced the Minuteman, was retired in 2005 as part of START II.[13]

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. The United States prefers to keep its MIRV deterrent on submarine-launched Trident Nuclear Missiles.[14]

Testing[edit]

A Minuteman III missile in its silo

Minuteman III missiles are regularly tested with launches from Vandenberg Air Force Base in order to validate the effectiveness, readiness, and accuracy of the weapon system, as well as to support the system's primary purpose, nuclear deterrence. The safety features installed on the Minuteman III for each test launch allow the flight controllers to terminate the flight at any time if the systems indicate that its course may take it unsafely over inhabited areas. Since these flights are for test purposes only, even terminated flights can send back valuable information to correct a potential problem with the system.

The 576th Flight Test Squadron is responsible for planning, preparing, conducting, and assessing all ICBM ground and flight tests.

Related programs[edit]

Influences[edit]

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[edit]

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". Minutemen also feature in Eagle Strike, by Anthony Horowitz, in which fictional power-crazed multimillionaire Damian Cray orders their release from Air Force One. In the film WarGames a failed Minuteman launch simulation exercise caused by a conflicted launch control officer is the impetus for the conversion of the missiles to full automatic control by the computer system that Matthew Broderick's character later hacks into.

Other roles[edit]

Mobile Minuteman[edit]

Mobile Minuteman was a program for rail-based ICBMs to help increase survivability and for which the USAF released details on October 12, 1959. The Operation Big Star performance test was from June 20 to August 27, 1960 at Hill Air Force Base, and the 4062nd Strategic Missile Wing (Mobile) was organized 1 December 1960 for 3 planned missile train squadrons, each with 10 trains carrying 3 missiles per train. During the Kennedy/McNamara cutbacks, the DoD announced "that it has abandoned the plan for a mobile Minuteman ICBM. The concept called for 600 to be placed in service--450 in silos and 150 on special trains, each train carrying 5 missiles."[15] After Kennedy announced on March 18, 1961, that the 3 squadrons were to be replaced with "fixed-base squadrons",[16] Strategic Air Command discontinued the 4062nd Strategic Missile Wing on 20 February 1962.

Air Launched ICBM[edit]

Air Launched ICBM was a STRAT-X proposal[17] in which SAMSO successfully conducted an Air Mobile Feasibility Test that airdropped a Minuteman from a C-5A Galaxy aircraft from 20,000 ft (6,100 m) over the Pacific Ocean. The missile fired at 8,000 ft (2,400 m), and the 10-second engine burn carried the missile to 20,000 feet again before it dropped into the ocean. Operational deployment was discarded due to engineering and security difficulties, and the capability was a negotiating point in the Strategic Arms Limitation Talks.[18][19]

Emergency Rocket Communications System (ERCS)[edit]

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 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 top of modified Minuteman-II ICBMs (LGM-30Fs) under the control of the 510th Strategic Missile Squadron located at Whiteman Air Force Base, Missouri.

The Minuteman ERCS may have been assigned the designation LEM-70A.[20]

Satellite launching role[edit]

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.

During the 1980s, surplus Minuteman missiles were used to power the Conestoga rocket produced by Space Services Inc. of America. It was the first privately developed rocket, but only saw three flights and was discontinued due to a lack of business. More recently, converted Minuteman missiles have been used to power the Minotaur line of rockets produced by Orbital Sciences.

Ground and air launch targets[edit]

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.

Operator[edit]

Connectivity of 91st SW Missile Field

 United States: The United States Air Force has been the only operator of the Minuteman ICBM weapons system, currently with three operational wings and one test squadron operating the LGM-30G. The active inventory in FY 2009 is 450 missiles and 45 Missile Alert Facilities (MAF).

Operational units[edit]

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 (thus the 319th Missile Squadron’s five LCCs cannot control the 320th Missile Squadron’s 50 LFs even though they are part of the same Space Launch Wing). Each Minuteman wing is assisted logistically by a nearby Missile Support Base (MSB).

Active[edit]

Active LGM-30 Minuteman deployment, 2010

Historical[edit]

Ellsworth AFB, South Dakota (24 November 1961 – 5 July 1994)
LGM-30B Minuteman I, 1963–1973
LGM-30F Minuteman II, 1971–1994
66th Missile Squadron
67th Missile Squadron
68th Missile Squadron
44th Missile Wing LGM-30 Minuteman Missile Launch Sites
Inactivated 1994 when Minuteman II phased out of inventory. All retired between December 3, 1991 and April 1994, with destruction of silos and alert facilities finishing in 1996.
400th Missile Squadron (Converted to LGM-118A Peacekeeper in 1987. Inactivated 2005. Peacekeepers retired.)
Grand Forks AFB, North Dakota (14 August 1964 – 30 September 1998)
LGM-30F Minuteman II, 1965–1973
LGM-30G Minuteman III, 1972–1998
446th Missile Squadron
447th Missile Squadron
448th Missile Squadron
321st Missile Wing LGM-30 Minuteman Missile Launch Sites
Inactivated by BRAC 1995; missiles reassigned to 341st SMW, however in 1995 it was decided to retire the Grand Forks missiles; the last missile was pulled from its silo in June 1998. Destruction of silos and control facilities began in October 1999; the last silo (H-22) was imploded August 24, 2001 (the last US silo destroyed per the 1991 START-I treaty).
564th Missile Squadron (Inactivated 2008, Minutemen retired.)
Whiteman AFB, Missouri (1 February 1963 – 31 July 1995)
LGM-30B Minuteman I, 1963–1965
LGM-30F Minuteman II, 1965–1995
508th Missile Squadron
509th Missile Squadron
510th Missile Squadron
351st Missile Wing LGM-30 Minuteman Missile Launch Sites
Inactivated under START-I. The first silo was imploded on December 8, 1993 and the last on December 15, 1997.
Minot AFB, North Dakota (28 June 1962 – 25 June 1968)
LGM-30B Minuteman I, 1962–1968
Replaced by the 91st Strategic Missile Wing in June 1968

Support[edit]

See also[edit]

Aircraft of comparable role, configuration and era
Related lists

Notes[edit]

  1. ^ a b c "Factsheets : LGM-30G Minuteman III". Af.mil. 2010-07-26. Archived from the original on 2012-12-12. Retrieved 2011-03-20. 
  2. ^ Unique and Complementary Characteristics of the U.S. ICBM and SLBM Weapons Systems by Mitch Bott (PDF), Center for Strategic and International Studies, Date unspecified, p. 76  .
  3. ^ Discussion of the Unique and Complementary Characteristics of the ICBM and SLBM Weapon Systems (PDF), Center for Strategic and International Studies/Northrop Grumman, 2009, p. 5 .
  4. ^ a b c "Photo Release – Northrop Grumman/Air Force Complete Guidance Upgrade Installations On Minuteman III ICBMs (NYSE:NOC)". Irconnect.com. 2008-03-11. Retrieved 2011-03-20. 
  5. ^ a b "Earmark Disclosure 81542, Minuteman III Solid Rocket Motor Warm Line Program (SRMWL)". WashingtonWatch.com. 2011-03-14. Retrieved 2011-03-20. 
  6. ^ Norris, R. S. and H. M. Kristensen U.S. nuclear forces, 2009 Bulletin of the Atomic Scientists March/April, 2009
  7. ^ "The 6555th, Chapter III, Section 8, The MINUTEMAN Ballistic Missile Test Program". Fas.org. Retrieved 2011-03-20. 
  8. ^ "BOEING LGM-30A MINUTEMAN IA". National Museum of the Air Force. Retrieved 13 November 2013. 
  9. ^ "Complete List of All U.S. Nuclear Weapons". Retrieved 9 February 2011. 
  10. ^ "Multiple Independently Targetable Reentry Vehicles (MIRVs)". 
  11. ^ "Life Extension Programs modernize ICBMs."
  12. ^ 2006 ATK press release on PRP[dead link]
  13. ^ Edwards, Joshua S. (2005-09-20). "Peacekeeper missile mission ends during ceremony". United States Air Force. Archived from the original on 2012-07-17. Retrieved 2009-05-28. 
  14. ^ http://www.navy.mil/navydata/fact_display.asp?cid=2200&tid=1400&ct=2
  15. ^ Flight: 844. December 21, 1961.  (cited by "Out of the Past: 50 Years Ago, December 1961". Aerospace America: 76.  )
  16. ^ title tbd (Kennedy speech), "The three mobile Minuteman squadrons funded in the January budget should be deferred for the time being and replaced by three more fixed-base squadrons (thus increasing the total number of missiles added by some two-thirds). Development work on the mobile version will continue." 
  17. ^ "History Milestones". U.S. Air Force. AF.mil. Archived from the original on 19 July 2012. Retrieved 24 February 2012. 
  18. ^ U.S. Air Force, Inside the AF.MIL Heritage section (Thursday, January 01, 1970 – Sunday, December 31, 1989)
  19. ^ Marti and Sarigul-Klijn, A Study of Air Launch Methods for RLVs. Doc No. AIAA 2001-4619, Mechanical and Aeronautical Engineering Dept, University of California, Davis, CA 95616
  20. ^ Parsch, Andreas (2002). "Boeing LEM-70 Minuteman ERCS". Directory of U.S. Military Rockets and Missiles. designation-systems.net. Retrieved 2011-01-10. 
  21. ^ Hill AFB, Utah
  22. ^ Vandenberg AFB, California

References[edit]

  • 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.
  • Heefner, Gretchen (2012). The Missile Next Door: The Minuteman in the American Heartland. Cambridge, MA: Harvard University Press.
  • 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.
  • TRW Systems (2001). Minuteman Weapon System History and Description.
  • Zuckerman, E. (1984). The Day after World War III. New York: Viking Press.

External links[edit]