Editing LGM-30 Minuteman (section)

=== Minuteman I (LGM-30A/B or SM-80/HSM-80A) ===
:''See also [[W56|W56 Warhead]]''

==== Deployment ====
The '''LGM-30A Minuteman I''' was first test-fired on 1 February 1961 at [[Cape Canaveral Air Force Station|Cape Canaveral]],<ref name="bbthmj" /><ref name="mmmfs61" /><ref name="6555th" /><ref name="lmtpit" /> entering into the [[Strategic Air Command]]'s arsenal in 1962. After the first batch of Minuteman I's were fully developed and ready for stationing, the [[United States Air Force]] (USAF) had originally decided to put the missiles at [[Vandenberg AFB]] in California, but before the missiles were set to officially be moved there it was discovered that this first set of Minuteman missiles had defective boosters which limited their range from their initial {{convert|6300|mi}} to {{convert|4300|mi}}. This defect would cause the missiles to fall short of their targets if launched over the [[North Pole]] as planned. The decision was made to station the missiles at [[Malmstrom AFB]] in [[Montana]] instead.<ref name="mmmfs61" /> These changes would allow the missiles, even with their defective boosters, to reach their intended targets in the case of a launch.<ref name="1996_dtic" />

The "improved" '''LGM-30B''' '''Minuteman I''' became operational at [[Ellsworth AFB]], [[South Dakota]], [[Minot AFB]], [[North Dakota]], [[F.E. Warren AFB]], [[Wyoming]], and [[Whiteman AFB]], [[Missouri]], in 1963 and 1964. All 800 Minuteman I missiles were delivered by June 1965. Each of the bases had 150 missiles emplaced; F.E. Warren had 200 of the Minuteman IB missiles. Malmstrom 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.

==== Specifications ====
The Minuteman I's length varied based on which variation one was to look at. The Minuteman I/A had a length of {{convert|53|ft|8|in|m|abbr=on|sp=us}} and the Minuteman I/B had a length of {{convert|55|ft|11|in|m|abbr=on|sp=us}}. The Minuteman I weighed roughly {{convert|65000|lb|kg|abbr=on|sp=us}}, had an operational range of {{convert|5500|nmi|mi km|abbr=on|sp=us}}<ref name="FAS_LGM-30-1" /> with an accuracy of about {{convert|1.5|mi|km|abbr=on|sp=us}}.<ref name="1996_dtic" /><ref name="2009_Polmar" /><ref name="1963_Bowman" />

==== Guidance ====
The Minuteman I Autonetics [[D-17B|D-17 flight computer]] used a rotating air bearing magnetic disk holding 2,560 "cold-stored" [[Word (computer architecture)|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 to 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 a flight, filtered command outputs were sent by 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.

==== Warhead ====
At its introduction into service in 1962, Minuteman I was fitted with the [[W59]] warhead with a yield of 1 Mt. Production for the W56 warhead with a 1.2 Mt yield began in March 1963 and W59 production was ended in July 1963 with a production run of only 150 warheads before being retired in June 1969. The W56 would continue production until May 1969 with a production run of 1000 warheads. Mods 0 to 3 were retired by September 1966 and the Mod 4 version would remain in service until the 1990s.<ref name=AtomArch>{{cite web|title=Complete List of All U.S. Nuclear Weapons|url=http://nuclearweaponarchive.org/Usa/Weapons/Allbombs.html|publisher=Nuclear Weapons Archive|access-date=12 April 2020}}</ref>

It's not clear exactly why the W59 was replaced by the W56 after deployment but issues with "... one-point safety" and "performance under aged conditions" were cited in a 1987 congressional report regarding the warhead.<ref name=CongReport>{{cite report |last1=Miller | first1=G.H.|last2=Brown|first2=P.S.|last3=Alonso|first3=C.T.|date=1987 |title=Report to Congress on stockpile reliability, weapon remanufacture, and the role of nuclear testing | osti=6032983|url=https://www.osti.gov/scitech/biblio/6032983 }}</ref> [[Chuck Hansen]] alleged that all weapons sharing the [[Tsetse (nuclear primary)|"Tsetse" nuclear primary]] design including the W59 suffered from a critical one-point safety issue and suffered premature tritium aging issues that needed to be corrected after entry into service.<ref name=Hansen>{{cite book | last = Hansen | first = Chuck | title = The Swords of Armageddon |volume=VI | publisher = Chukelea Publications | year = 1995a }}</ref>