Editing Titan (rocket family) (section)

===Titan II missile===
{{Main|LGM-25C Titan II}}
Most of the Titan rockets were the Titan II ICBM and their civilian derivatives for [[NASA]]. The Titan II used the [[LR-87#LR-87-5|LR-87-5]] engine, a modified version of the [[LR-87]], that used a [[hypergolic propellant]] combination of [[nitrogen tetroxide]] (NTO) for its oxidizer and [[Aerozine 50]] (a 50/50 mix of [[hydrazine]] and [[unsymmetrical dimethylhydrazine]] (UDMH) instead of the liquid oxygen and RP-1 propellant of the Titan I.

The first Titan II guidance system was built by [[ACDelco|AC Spark Plug]]. It used an [[inertial measurement unit]] made by AC Spark Plug derived from original designs from the [[Charles Stark Draper Laboratory]] at MIT. The missile guidance computer (MGC) was the IBM [[ASC-15]]. When spares for this system became hard to obtain, it was replaced by a more modern guidance system, the [[Delco Electronics]] Universal Space Guidance System (USGS). The USGS used a [[Delco Carousel|Carousel IV]] IMU and a Magic 352 computer.<ref>David K. Stumpf. ''Titan II: A History of a Cold War Missile Program.'' University of Arkansas Press, 2000. {{ISBN|1-55728-601-9}}. pp. 63–67.</ref> The USGS was already in use on the Titan III space launcher when work began in March 1978 to replace the Titan II guidance system. The main reason was to reduce the cost of maintenance by $72 million per year; the conversions were completed in 1981.<ref>Bonds, Ray Editor. ''The Modern US War Machine: An encyclopedia of American military equipment and strategy.'' Crown Publishers, New York City 1989. {{ISBN|0-517-68802-6}}. p. 233.</ref>

====Hypergolic propellants====
{{See also|Hypergolic propellant}}
Liquid oxygen is dangerous to use in an enclosed space, such as a [[missile silo]], and cannot be stored for long periods in the booster oxidizer tank.  Several Atlas and Titan I rockets exploded and destroyed their silos, although without loss of life.{{cn|date=October 2023}} The Martin Company was able to improve the design with the Titan II. The RP-1/LOX combination was replaced by a room-temperature fuel whose oxidizer did not require [[cryogenic]] storage. The same first-stage rocket engine was used with some modifications. The diameter of the second stage was increased to match the first stage. The Titan II's hypergolic fuel and oxidizer ignited on contact, but they were highly toxic and corrosive liquids. The fuel was [[Aerozine 50]], a 50/50 mix of hydrazine and UDMH, and the oxidizer was NTO.

====Accidents at silos====
There were several accidents in Titan II silos resulting in loss of life and/or serious injuries.

In August 1965, 53 construction workers were killed in fire in a missile silo northwest of [[Searcy, Arkansas]]. The fire started when hydraulic fluid used in the Titan II was ignited by a welding torch.<ref>{{cite news|
url = https://news.google.com/newspapers?id=hYIKAAAAIBAJ&sjid=h0sDAAAAIBAJ&pg=3877%2C1878649 |
agency = Associated Press |
newspaper = Ellensburg Daily Record |
title = Escape Route Blocked in Silo Disaster |
date = August 13, 1965 |
page = 1 |
access-date = 2011-01-03
}}</ref><ref name=bissmhtf>{{cite news |url=https://news.google.com/newspapers?id=fZckAAAAIBAJ&sjid=raQFAAAAIBAJ&pg=3916%2C4715863 |newspaper=Montreal Gazette |title=Blast is second serious mishap in 17-year-old U.S. Titan fleet |date=September 20, 1980 |page=2 }}</ref>

The liquid fuel missiles were prone to developing leaks of their toxic propellants. At a silo outside [[Rock, Kansas]], an oxidizer transfer line carrying NTO ruptured on August 24, 1978.<ref>{{cite news|
url = https://news.google.com/newspapers?id=r-kLAAAAIBAJ&sjid=NloDAAAAIBAJ&pg=5707%2C1305223 |
agency = UPI |
newspaper = St. Petersburg Times |
title = 1 killed, 6 injured when fuel line breaks at Kansas Titan missile site |
date = August 25, 1978 |
page = 4 |
access-date = 2009-10-18
}}</ref> An ensuing orange vapor cloud forced 200 rural residents to evacuate the area.<ref>{{cite news|
url = https://news.google.com/newspapers?id=lsUSAAAAIBAJ&sjid=CfsDAAAAIBAJ&pg=5959%2C7675769 |
agency = Associated Press |
newspaper = The Ledger |
title = Thunderhead Of Lethal Vapor Kills Airman At Missile Silo |
date = August 25, 1978 |
page = 7 |
access-date = 2009-10-18
}}</ref> A staff sergeant of the maintenance crew was killed while attempting a rescue and a total of twenty were hospitalized.<ref name=amnatsres>{{cite news|url=https://news.google.com/newspapers?id=FIsyAAAAIBAJ&sjid=oeYFAAAAIBAJ&pg=6774%2C4610225 |newspaper=Lawrence Journal-World |agency=Associated Press |title=Airman at Titan site died attempting rescue |date=August 26, 1978 |page=2 }}</ref>

Another site at [[Potwin, Kansas]] leaked NTO oxidizer in April 1980 with no fatalities,<ref name=afpllk>{{cite news |url=https://news.google.com/newspapers?id=MqgyAAAAIBAJ&sjid=R-cFAAAAIBAJ&pg=6830%2C4734085 |newspaper=Lawrence Journal-World |agency=Associated Press |title=Air Force plugs leak in Kansas missile silo |date=April 23, 1980 |page=16 }}</ref> and was later closed.

In September 1980, at Titan II silo 374-7 near [[Damascus, Arkansas]], a technician dropped an {{convert|8|lb|abbr=on}} socket that fell {{convert|70|ft|0|abbr=on}}, bounced off a thrust mount, and broke the skin of the missile's first stage,<ref name=exwrtms>{{cite news |url=https://news.google.com/newspapers?id=AeFLAAAAIBAJ&sjid=sosDAAAAIBAJ&pg=6041%2C2966399|newspaper=Free Lance-Star |location= Fredericksburg, VA |agency=Associated Press |title=Explosion wrecks Titan missile silo |last=Colby |first=Terri |date=September 19, 1980 |page=1}}</ref> over eight hours prior to an [[1980 Damascus Titan missile explosion|eventual explosion]].<ref name=wamfmst>{{cite news |url=https://news.google.com/newspapers?id=8gYgAAAAIBAJ&sjid=t2QFAAAAIBAJ&pg=4301%2C4439202 |newspaper=Lewiston (ME) Daily Sun |agency= Associated Press |title=Warhead apparently moved from Arkansas missile site  |date=September 23, 1980 |page=10}}</ref> The puncture occurred about 6:30&nbsp;p.m.<ref name=cadvdisre>{{cite news |url=https://news.google.com/newspapers?id=KUcgAAAAIBAJ&sjid=354EAAAAIBAJ&pg=6731%2C5119654 |newspaper=Tuscaloosa News |title=Caution advice disregarded at Titan missile site? |agency=Washington Post |date=October 23, 1980 |page=23 }}</ref> and when a leak was detected shortly after, the silo was flooded with water and civilian authorities were advised to evacuate the area.<ref name=msbhttw >{{cite news|url=https://news.google.com/newspapers?id=sUFYAAAAIBAJ&sjid=QvkDAAAAIBAJ&pg=6410%2C5386804 |newspaper=Spokane Daily Chronicle |agency=Associated Press |last=Colby |first=Terri |title=Missile silo blast hurts 22 workers |date=September 19, 1980 |page=1 }}</ref> As the problem was being attended to at around 3 a.m.,<ref name=cadvdisre/> leaking rocket fuel ignited and blew the {{convert|8000|lb|-1|abbr=on}} nuclear warhead out of the silo. It landed harmlessly several hundred feet away.<ref>[https://web.archive.org/web/20070313082220/http://www.time.com/time/magazine/article/0,9171,952781,00.html "Light on the Road to Damascus"] ''Time'' magazine, September 29, 1980. Retrieved 2006-09-12</ref><ref name=twifliw>{{cite news|url=https://news.google.com/newspapers?id=a35QAAAAIBAJ&sjid=fVoDAAAAIBAJ&pg=6173%2C3636095 |newspaper=St. Petersburg Times |agency=wire services |title=Titan warhead is reported lying in Arkansas woods |date=September 21, 1980 |page=1A }}</ref><ref name=dwhlisl>{{cite news|url=https://news.google.com/newspapers?id=T_JVAAAAIBAJ&sjid=6eEDAAAAIBAJ&pg=5975%2C5570857 |newspaper=Eugene Register-Guard |agency=wire services |title=Did warhead leave its silo? |date=September 21, 1980 |page=1A }}</ref> There was one fatality and 21 were injured,<ref name=ttcontrvs>{{cite news |url=https://news.google.com/newspapers?id=skFYAAAAIBAJ&sjid=QvkDAAAAIBAJ&pg=6890%2C5741844 |title=The Titan controversy |newspaper=Spokane Daily Chronicle |agency=Associated Press |date=September 20, 1980 |page=2}}</ref> all from the emergency response team from [[Little Rock Air Force Base|Little Rock AFB]].<ref name=cadvdisre/><ref name=wboftbl >{{cite news|url=https://news.google.com/newspapers?id=IIIfAAAAIBAJ&sjid=6p4EAAAAIBAJ&pg=5474%2C3917064 |newspaper=Tuscaloosa News |agency=Associated Press |title=Warhead blown off in Titan blast |page=1A |date = 21 September 1980}}</ref> The explosion blew the 740-ton launch tube cover {{convert|200|ft|-1|abbr=on}} into the air and left a [[Explosion crater|crater]] {{convert|250|ft|0}} in diameter.<ref name=arkrecma>{{cite news|url=https://news.google.com/newspapers?id=aaArAAAAIBAJ&sjid=bvwFAAAAIBAJ&pg=6929%2C3795680 |newspaper=Nashua (NH) Telegraph |agency=Associated Press |title=Arkansas recalls missile accident |date=September 19, 1981 |page=14 }}</ref>
<!-- "This marked the beginning of the end for the Titan II as an ICBM." commented out because it was not a tech dropping a wrench that marked the beginning of the end; it was the initial introduction of the Peacekeeper as a replacement that did. -->

====Missile retirement====
The 54 Titan IIs<ref name=accwth>{{cite news|url=https://news.google.com/newspapers?id=Y1VOAAAAIBAJ&sjid=zO4DAAAAIBAJ&pg=5298%2C1674649 |newspaper=Spokesman-REview |agency=Washington Post |last=Pincus |first=Walter |title=Titan II: 54 accidents waiting to happen  |date=September 20, 1980 |page=5}}</ref> in Arizona, Arkansas, and Kansas<ref name=ttcontrvs/> were replaced by 50 [[LG-118A Peacekeeper|MX "Peacekeeper"]] [[solid-fuel rocket]] missiles in the mid-1980s; the last Titan II silo was deactivated in May 1987.<ref name=alt2ide>{{cite news |url=https://news.google.com/newspapers?id=coRPAAAAIBAJ&sjid=qiQEAAAAIBAJ&pg=6754%2C1474087 |newspaper=Times-News |location=Hendersonville, NC |agency=Associated Press |last=Charton |first=Scott |title=America's last Titan 2 nuclear missile is deactivated |date=May 7, 1987 |page=3 }}</ref> The 54 Titan IIs had been fielded along with a thousand [[LGM-30 Minuteman|Minuteman]] missiles from the mid-1960s through the mid-1980s.

A number of Titan I and Titan II missiles have been distributed as museum displays across the United States.