LGM-30 Minuteman
From Open Encyclopedia
| Image:Minuteman3launch.jpg | |
| LGM-30G Minuteman Missile | |
|---|---|
| Function | Intercontinental ballistic missile |
| Contractor | Boeing |
| Unit cost | $7,000,000 |
| Deployment | 1960 |
| General characteristics | |
| Engine | Three solid-propellant rocket motors; first stage - Thiokol; second stage - Aerojet-General; third stage - United Technologies Chemical Systems Division |
| Launch mass | 79,432 pounds (32,158 Kg) |
| Length | 59.9 feet (18 meters) |
| Diameter | 5.5 feet (1.67 meters) |
| Wing span | n/a |
| Speed | Approximately 15,000 mph (Mach 23, or 24,000 km/h, or 7 km/s) |
| Range | 6,000-plus miles (5,200 nautical miles, or 10,000 km) |
| Flying altitude | 700 miles (1,120 kilometers) |
| Warhead | Nuclear |
| Guidance | Inertial |
| Fuzes | n/a |
| Launch platform | Silo |
The LGM-30 Minuteman is a United States nuclear missile, a land-based intercontinental ballistic missile (ICBM). As of 2005 it is the only land-based ICBM in service in the United States. It is complemented by the sea-launched Trident missile ICBM (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 surface targets; and the M indicates that it is a guided missile.
The name "Minuteman" comes from the Revolutionary War's Minutemen.
Contents |
Current model
The current Minuteman force consists of 500 Minuteman IIIs in missile silos around F.E. Warren Air Force 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"), a liquid-fuel propulsion system rocket engine used to fine-tune the trajectory of the reentry vehicle and/or dispense individual warheads to separate targets across a broad area. The missile has a gimballed inertial guidance system.
The post-boost stage carries, in addition to the warhead(s), penetration aids such as chaff 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 is now considering keeping 800 warheads on the Minuteman force.
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. 1998 USAF plans are to operate it until 2025.
The LG-118A Peacekeeper mx ICBM which was meant to replace the Minuteman was due to be retired by 2005. The Peacekeeper suffered from controversy over various mobile basing schemes, but the original Minuteman basing plan included being deployed on railroad cars. This idea was evidently discarded because of security problems of having nuclear weapons rumble by neighborhoods and cities on railroad tracks.
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)
The Propulsion Replacement Program extends the life, maintains the performance, and improves the reliability of the operational ICBM force by replacing the old solid propellant boosters (downstages) with new "environmently friendly" boosters.
Single Reentry Vehicle (SRV)
The Single Reentry Vehicle (SRV) modification allows the United States ICBM force to abide by START treaty requirements by reconfigure Minuteman III missiles from 3 re-entry vehicles down to one.
Safety Enhanced Reentry Vehicle (SERV)
Beginning in 2006, Mk-21/W87 RVs from the deactivated LG-118A 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 W87 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 provide a greater probability of damage.
Organization
The basic tactical unit of a Minuteman wing is the squadron, consisting of five flights. Each squadron 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 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).
Units
Six operational units and one test squadron in the United States Air Force has operated the Minuteman missile in its varying configurations:
- Wing Zero: 576th Flight Test Squadron - Vandenberg AFB, California
- Wing One: 341st Strategic Missile Wing - Malmstrom AFB, Montana
- 10th Missile Squadron
- 12th Missile Squadron
- 490th Missile Squadron
- 564th Missile Squadron - "The Odd Squad"
- Wing Two: 44th Strategic Missile Wing - Ellsworth AFB, South Dakota
- 66th Missile Squadron
- 67th Missile Squadron
- 68th Missile Squadron
- Wing Three: 455th/91st Strategic Missile Wing - Minot AFB, North Dakota - "Roughriders"
- 740th Missile Squadron - "Vulgar Vultures"
- 741st Missile Squadron - "Gravelhaulers"
- 742nd Missile Squadron - "Wolf Pack"
- Wing Four: 351st Strategic Missile Wing - Whiteman AFB, Missouri
- 508th Missile Squadron
- 509th Missile Squadron
- 510th Missile Squadron
- Wing Five: 90th Strategic Missile Wing - F.E. Warren AFB, Wyoming
- 319th Missile Squadron
- 320th Missile Squadron
- 321st Missile Squadron
- Wing Six: 321st Strategic Missile Wing - Grand Forks AFB, North Dakota
- 446th Missile Squadron
- 447th Missile Squadron
- 448th Missile Squadron
History
Image:Minuteman I.jpg The Minuteman I and 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)
Image:Minuteman I Computer D-17.jpg
The LGM-30A Minuteman I entered into the Strategic Air Command's arsenal in 1962, at Malmstrom AFB, Montana; the 'improved' LGM-30B became operational at Ellsworth AFB, South Dakota, Minot AFB, North Dakota, F.E. Warren AFB, Wyoming, and Whiteman AFB, Missouri in 1963. All 800 Minuteman I missiles were delivered by June 1965. Each of the bases had 150 missiles emplaced, except for F.E Warren AFB, which had 200 missiles.
The Minuteman I Autonetics D-17 flight computer used a rotating magnetic disk for about 4 kB of primary storage. Unlike modern computers, which use descendants of that technology for secondary storage on hard disk, this was the active computer memory. At the time, this was a small and inexpensive method to store data, although it was extremely slow by modern standards. The 5 ms average access time is about 300,000 times slower than the PC400 DDR SDRAM commonly used as main memory in home PCs around the year 2005.
The disk storage was considered completely immune to radiation from nearby nuclear explosions, making it an ideal storage medium, if a bit slow. To overcome speed problems, the contractor (the Autonetics Division of North American Aviation, which produced small commercial computers that used a disk for memory) had developed special software that optimized the placement of the instructions on the disk to give the system a speed boost (a technique employed on earlier magnetic drum computers).
Minuteman II (LGM-30F)
Image:Minuteman II.jpg 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 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 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 ABM system. The payload consisted of a single Mk 11C reentry vehicle containing a W56 nuclear warhead with a yield of 1.2 MT.
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 LG-118A, as these latter missiles were introduced into modified Minuteman silos.
The Minuteman II program was economically crucial to the development of integrated circuits. It was the first mass-produced system to use a computer constructed from integrated circuits, and used most of the production of such circuits from 1962 through 1967. The other major customer of these circuits was the Apollo Guidance Computer, which had similar weight and ruggedness constraints. The Minuteman II 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 Strategic Missile 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)
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, with the third stage improved with a new fluid-injected motor, giving finer control than the previous four nozzle system.
The Minuteman III Honeywell HDC-701 flight computer used NDRO (non-destructive read out) plated wire memory instead of rotating magnetic disk for primary storage.
The Guidance Replacement Program (GRP), initiated in 1993, flight computer uses radiation-resistant semiconductor RAM.
Influences
Image:Minuteman guidance computer.jpg
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 has recently been created. It preserves a Launch 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 about a rail-based counterpart. On 12 Oct 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 20 June to 27 August 1960 at Hill AFB, Utah. The United States Air Force then activated the 4062nd Mobile Missile Wing on 1 Dec 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 1 Dec 1961, the Department of Defense deleted the three mobile missile squadrons from its budget. The USAF officially deactivated the 4062nd Mobile Missile Wing on 20 Feb 1962.
The idea for a rail-based missile system was kept alive throught the LG-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 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 AFB, 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.
See also Minotaur (rocket).
National Missile Defense Role
References
- Gibson, James N. Nuclear Weapons of the United States. Atglen, Pennsylvania: Schiffer Publishing Ltd, 1996. ISBN 0764300636. Encyclopedia; contains history of Minuteman ICBM.
- 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.
- Lloyd, A. (2000) Cold War Legacy: A Tribute to the Strategic Air Command: 1946-1992. New York: Turner Publishing.
- Zuckerman, E. (1984) The Day after World War III. New York: Viking Press.
External links
- 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 ICBM History site
- Minuteman Missile National Historic Site
- U. S. Air Force Fact Sheet - LGM-30
|
Lists of Aircraft | Aircraft manufacturers | Aircraft engines | Aircraft engine manufacturers Airports | Airlines | Air forces | Aircraft weapons | Missiles | Timeline of aviation |
es:Misil Minuteman id:Peluru kendali Minuteman ms:Peluru berpandu Minuteman pl:LGM-30 Minuteman
