View source for Titan (rocket family)

{{Short description|Family of launch vehicles used in U.S. Air Force and space programs (1959–2005)}}
{{See also|LGM-25 Titan}}
{{Redirect|Titan V|the graphics card by [[Nvidia]]|Volta (microarchitecture)}}
{{Infobox rocket
| name = Titan family
| image = Titan Missile Family.png
| manufacturer = [[Glenn L. Martin Company]]
| status = Retired
|launches=368|first=December 20, 1958<ref>{{cite web|url=http://www.geocities.com/titan_1_missile/chronology.htm |title=Titan 1 Chronology |work=Titan 1 ICBM History Website |publisher=Geocities.com |last=Barton |first=Rusty |date=2003-11-18 |access-date=2005-06-05 |archive-url=https://web.archive.org/web/20070325085848/http://www.geocities.com/titan_1_missile/chronology.htm |archive-date=March 25, 2007 |url-status=dead }}</ref>|last=October 19, 2005|caption=The Titan rocket family, from left to right: Titan [[HGM-25A Titan I|I]] (ICBM), [[LGM-25C Titan II|II]] (ICBM), [[Titan II GLV|II GLV]] (manned), [[Titan IIIB|IIIB]], [[Titan IIIC|IIIC]], [[Titan IIIM|IIIM]] (manned), [[Titan IIIE|IIIE]]|derivatives=[[Titan I]]<br />[[LGM-25C Titan II|Titan II]]<br />[[Titan IIIA]]<br />[[Titan IIIB]]<br />[[Titan IIIC]]<br />[[Titan IIID]]<br />[[Titan IIIE]]<br />[[Titan IIIM]]<br/>[[Titan 34D]]<br />[[Titan IV]]|country-origin=[[United States]]}}

'''Titan''' was a family of American [[intercontinental ballistic missile]]s (ICBM) and [[medium-lift launch vehicle|medium-]] and [[heavy-lift launch vehicle|heavy]]-lift [[expendable launch system|expendable]] [[launch vehicle]]s used between 1959 and 2005. The [[Titan I]] and [[Titan II]] served as part of the [[United States Air Force]]'s ICBM arsenal until 1987, while later variants were adapted for space launch purposes. Titan launch vehicles were used for 368 missions in total, including all [[Project Gemini]] crewed flights in the mid-1960s, as well as numerous U.S. military, civilian, and scientific payloads—ranging from [[reconnaissance satellite]]s to [[space probe]]s sent throughout the [[Solar System]].

==Titan I missile==
{{Main|HGM-25A Titan I}}
[[File:Titan 1 ICBM.jpg|thumb|[[HGM-25A Titan I|Titan I ICBM]]|left|200x200px]]
The HGM-25A Titan I, built by the [[Glenn L. Martin Company|Martin Company]], was the first version of the Titan family of rockets.  It began as a backup ICBM project in case the [[SM-65 Atlas]] was delayed.  It was a two-stage rocket operational from early 1962 to mid-1965 whose [[LR-87]] booster engine was powered by [[RP-1]] (kerosene) and [[liquid oxygen]] (LOX). The ground guidance for the Titan was the [[UNIVAC]] [[ATHENA computer]], designed by [[Seymour Cray]], based in a hardened underground bunker.<ref>Stakem, Patrick H. The History of Spacecraft Computers from the V-2 to the Space Station, 2010, PRB Publishing, {{ASIN|B004L626U6}}{{ISBN?}}</ref> Using radar data, it made course corrections during the burn phase.

Unlike decommissioned Thor, Atlas, and Titan II missiles, the Titan I inventory was scrapped and never reused for space launches or [[reentry vehicle|RV]] tests, as all support infrastructure for the missile had been converted to the Titan II/III family by 1965.{{citation_needed|date=July 2019}}

==Titan II==
{{Main|LGM-25C Titan II|Titan II GLV|Titan 23G}}The Titan II family consists of the [[LGM-25C Titan II|Titan II ICBM]] and two later versions adapted for space launches, the [[Titan II GLV]] and the [[Titan 23G]].<gallery>
File:Titan II launch.jpg|[[LGM-25C Titan II|Titan II ICBM]] 
File:Gemini-Titan 11 Launch - GPN-2000-001020.jpg|[[Titan II GLV]]
File:Titan 23G rocket.gif|[[Titan 23G]]
</gallery>

===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.{{citation needed|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.

===Titan II launch vehicle===
{{Main|Titan II GLV}}
The most famous use of the civilian Titan II was in the NASA [[Project Gemini|Gemini program]] of crewed space capsules in the mid-1960s. Twelve Titan II GLVs were used for [[Project Gemini]]. Two flights were uncrewed and the remaining ten carried two-person crews. All of the launches were successful.

===Titan 23G===
{{Main|Titan 23G}}
Starting in the late 1980s, some of the deactivated Titan IIs were converted into space [[launch vehicle]]s to be used for launching U.S. Government payloads. 
Titan 23G rockets consisted of two stages burning [[liquid rocket propellant|liquid propellant]]. The first stage was powered by one [[Aerojet]] [[LR87]] engine with two combustion chambers and nozzles, and the second stage was propelled by an [[LR91]]. On some flights, the spacecraft included a kick motor, usually the [[Star (rocket stage)|Star-37XFP-ISS]]; however, the [[Star (rocket stage)|Star-37S]] was also used.<ref name="GSP"/>

Thirteen were launched from [[Vandenberg Space Launch Complex 4|Space Launch Complex 4W]] (SLC-4W) at [[Vandenberg Air Force Base]] starting in 1988.<ref name="GSP">{{cite web|url=http://space.skyrocket.de/doc_lau/titan-2.htm|title=Titan-2|last=Krebs|first=Gunter|publisher=Gunter's Space Page |access-date=2009-04-29}}</ref> The final such vehicle launched a [[Defense Meteorological Satellite Program]] (DMSP) weather satellite on 18 October 2003.<ref>{{cite web |
url = http://spaceflightnow.com/titan/g9/031018launch.html |
title = U.S. weather satellite finally escapes grasp of hard luck |
work = spaceflightnow.com |
author = Ray, Justin |
date = October 18, 2003 |
access-date = 2009-10-18
}}</ref>

==Titan III==
{{Main|Titan IIIA|Titan IIIB|Titan IIIC|Titan IIID|Titan IIIE|Titan IIIM|Titan 34D|Commercial Titan III}}
The Titan III was a modified Titan II with optional [[solid rocket booster]]s. It was developed on behalf of the [[United States Air Force]] (USAF) as a heavy-lift satellite launcher to be used mainly to launch American military payloads and civilian intelligence agency satellites such as the [[Vela (satellite)|Vela Hotel]] nuclear-test-ban monitoring satellites, observation and reconnaissance satellites (for intelligence-gathering), and various series of defense communications satellites.{{citation_needed|date=July 2019}} As USAF project, Titan III was more formally known as '''Program 624A''' ('''SSLS'''), '''Standard Space Launch System''', '''Standardized Space Launch System''', '''Standardized Space Launching System''' or '''Standard Space Launching System''' (all abbreviated '''SSLS''').<ref>{{Cite journal|last=Bleymaier |first=Joseph|date=1963-12-11|title=The Titan III Standardized Space Launch System |url=https://arc.aiaa.org/doi/abs/10.2514/6.1963-1407|journal=Heterogeneous Combustion Conference|language=en-US|location=Reston, Virginia|publisher=American Institute of Aeronautics and Astronautics|doi=10.2514/6.1963-1407|url-access=subscription}}</ref><ref>{{Cite report|date=1962-11-01|title=Program 624A. Program Documentation Requirements General Specification|url=https://apps.dtic.mil/sti/citations/AD0431109|archive-url=https://web.archive.org/web/20220415145902/http://www.dtic.mil/docs/citations/AD0431109|url-status=live|archive-date=April 15, 2022|language=en}}</ref><ref>{{Cite book|url=https://books.google.com/books?id=HxU-9UeDCI0C&pg=PA496|title=New Scientist|date=1962-09-06|publisher=Reed Business Information|language=en}}{{Dead link|date=September 2024 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

The Titan III core was similar to the Titan II, but had a few differences. These included:{{citation_needed|date=July 2019}}

*Thicker tank walls and ablative skirts to support the added weight of upper stages
*Radio ground guidance in place of the inertial guidance on ICBM Titan IIs
*Guidance package placed on the upper stages (if present)
*Removal of retrorockets and other unnecessary ICBM hardware
*Slightly larger propellant tanks in the second stage for longer burn time; since they expanded into some unused space in the avionics truss, the actual length of the stage remained unchanged.

The Titan III family used the same basic LR-87 engines as Titan II (with performance enhancements over the years), however SRB-equipped variants had a heat shield over them as protection from the SRB exhaust and the engines were modified for air-starting.{{citation_needed|date=July 2019}}

===Avionics===
The first guidance system for the Titan III used the AC Spark Plug company IMU (inertial measurement unit) and an IBM ASC-15 guidance computer from the Titan II. For the Titan III, the ASC-15 drum memory of the computer was lengthened to add 20 more usable tracks, which increased its memory capacity by 35%.<ref>Paul O. Larson. "Titan III Inertial Guidance System," p.4.</ref>

The more-advanced Titan IIIC used a [[Delco Carousel]] VB IMU and MAGIC 352 Missile Guidance Computer (MGC).<ref>{{cite web|url=https://apps.dtic.mil/dtic/tr/fulltext/u2/a007056.pdf|last=Liang|first=A.C.|title=Dynamic Calibration for Delco's Carousel VB IMU|date=March 2022|access-date=November 22, 2022|archive-date=November 24, 2022|archive-url=https://web.archive.org/web/20221124231042/https://apps.dtic.mil/dtic/tr/fulltext/u2/a007056.pdf|url-status=dead}}</ref><ref>A.C. Liang and D.L. Kleinbub. "Navigation of the Titan IIIC space launch vehicle using the Carousel VB IMU." AIAA Guidance and Control Conference, Key Biscayne, FL, 20–22 August 1973. AIAA Paper No. 73-905.</ref><gallery>
File:Titan-3A with LES-1 satellite 11-02-1965.jpg|[[Titan IIIA]]
File:Titan 23B.jpg|[[Titan IIIB]]
File:DF-SC-84-05192 cropped.jpeg|[[Titan IIIC]]
File:Titan IIID with KH-11 2 (USAF).jpg|[[Titan IIID]]
File:Titan 3E Centaur launches Voyager 2.jpg|[[Titan IIIE]]
File:Dorian 10.jpg|[[Titan IIIM]]
File:DF-SC-83-03173 cropped.jpeg|[[Titan 34D]]
File:Commercial Titan 3 launching Mars Observer.jpg|[[Commercial Titan III]] 
</gallery>

===Titan IIIA===
{{Main|Titan IIIA}}
The Titan IIIA was a prototype rocket booster and consisted of a standard Titan II rocket with a [[Transtage]] upper stage.{{citation_needed|date=July 2019}}

===Titan IIIB===
{{Main|Titan IIIB}}
The Titan IIIB with its different versions (23B, 24B, 33B, and 34B) had the Titan III core booster with an [[RM-81 Agena|Agena D]] upper stage. This combination was used to launch the [[KH-8 GAMBIT]] series of intelligence-gathering satellites. They were all launched from Vandenberg Air Force Base, due south over the Pacific into [[polar orbit]]s. Their maximum payload mass was about 7,500&nbsp;lb (3,000&nbsp;kg).<ref>Titan 3B Launched, Aviation Week & Space Technology, August 8, 1966, p. 29</ref>

===Titan IIIC===
{{Main|Titan IIIC}}
The powerful Titan IIIC used a Titan III core rocket with two large strap-on solid-fuel boosters to increase its launch thrust and maximum payload mass. The solid-fuel boosters that were developed for the Titan IIIC represented a significant engineering advance over previous solid-fueled rockets, due to their large size and thrust, and their advanced thrust-vector control systems.{{citation_needed|date=July 2019}}

===Titan IIID===
{{Main|Titan IIID}}
The Titan IIID was the Vandenberg Air Force Base version of the Titan IIIC, without a Transtage, that was used to place members of the [[Key Hole]] series of reconnaissance satellites into [[polar orbit|polar]] [[low Earth orbit]]s.{{citation_needed|date=July 2019}}

===Titan IIIE===
{{Main|Titan IIIE}}
The Titan IIIE, with a high-[[specific impulse|specific-impulse]] [[Centaur rocket|Centaur]] upper stage, was used to launch several scientific spacecraft, including both of NASA's two [[Voyager program|Voyager space probes]] to Jupiter, Saturn and beyond, and both of the two [[Viking program|Viking]] missions to place two orbiters around Mars and two instrumented landers on its surface.<ref>Second Viking Launched Prior to Thunderstorm, Aviation Week & Space Technology, September 15, 1975, page 20</ref><ref>{{cite web |url= http://nssdc.gsfc.nasa.gov/planetary/viking.html  |title=Viking Mission to Mars |publisher=NASA= |access-date=2016-02-16}}</ref>

===Titan 34D===
{{Main|Titan 34D}}
The Titan 34D featured Stage 1 and Stage 2 stretched with more powerful [[UA120|UA1206]] solid motors. A variety of upper stages were available, including the [[Inertial Upper Stage]], the [[Transfer Orbit Stage]], and the [[Transtage]].<ref>{{cite web |url=http://www.astronautix.com/t/titan34d.html |archive-url=https://web.archive.org/web/20161228084822/http://astronautix.com/t/titan34d.html |url-status=dead |archive-date=December 28, 2016 |title=Titan 34D |website=Astronautix.com |publisher=Encyclopedia Astronautica |access-date=19 March 2019}}</ref> The Titan 34D made its maiden flight on 30 October 1982 with two [[DSCS]] defense [[communications satellite]]s for the United States [[Department of Defense (USA)|Department of Defense]] (DOD).

===Commercial Titan III===
{{Main|Commercial Titan III}}
Derived from the Titan 34D and originally proposed as a medium-lift expendable launch system for the US Air Force, who selected the Delta II instead. Development was continued as a commercial launch system, and the first rocket flew in 1990. The Commercial Titan III differed from the Titan 34D in that it had a stretched second stage, and a larger payload fairing to accommodate dual satellite payloads.

===Titan IIIM===
{{Main|Titan IIIM}}
The Titan IIIM was intended to launch the [[Manned Orbiting Laboratory]] and other payloads. Development was cancelled in 1969. The projected [[UA120#UA1207|UA1207]] solid booster rockets were eventually used on the [[Titan IV]], while the extended core was used in the 3B and 34B variants of the [[Titan IIIB]].<ref>{{cite web |url=http://www.astronautix.com/t/titan3m.html |archive-url=https://web.archive.org/web/20160820052106/http://www.astronautix.com/t/titan3m.html |url-status=dead |archive-date=August 20, 2016 |title=Titan 3M |work=Astronautix.com |access-date=25 June 2016}}</ref><ref name="Shayler2002">{{cite book |chapter-url=https://books.google.com/books?id=c8PpO58QwowC&pg=PA376 |chapter=Military Gemini |title=Gemini: Steps to the Moon |publisher=Springer-Praxis |first=David J. |last=Shayler |date=2002 |isbn=1-85233-405-3}}</ref>

==Titan IV==
{{Main|Titan IV}}
The Titan IV was an extended length Titan III with solid rocket boosters on its sides. The Titan IV could be launched with a [[Centaur (rocket stage)|Centaur]] upper stage, the USAF [[Inertial Upper Stage]] (IUS), or no upper stage at all. This rocket was used almost exclusively to launch US military or Central Intelligence Agency payloads. However, it was also used for a purely scientific purpose to launch the NASA–ESA [[Cassini probe|Cassini / Huygens space probe]] to [[Saturn]] in 1997. The primary intelligence agency that needed the Titan IV's launch capabilities was the [[National Reconnaissance Office]] (NRO).{{citation_needed|date=July 2019}}

When it was being produced, the Titan IV was the most powerful uncrewed rocket available to the United States, with proportionally high manufacturing and operations expenses. By the time the Titan IV became operational, the requirements of the [[United States Department of Defense|Department of Defense]] and the NRO for launching satellites had tapered off due to improvements in the longevity of reconnaissance satellites and the declining demand for reconnaissance that followed the internal disintegration of the [[Soviet Union]]. As a result of these events and improvements in technology, the unit cost of a Titan IV launch was very high. Additional expenses were generated by the ground operations and facilities for the Titan IV at Vandenberg Air Force Base for launching satellites into polar orbits. Titan IVs were also launched from the [[Cape Canaveral Air Force Station]] in Florida,<ref>{{Cite web|url=http://www.space.com/missionlaunches/launches/titan4_dsp_launch_010806.html|title=Titan 4B and Cape Canaveral|website=[[Space.com]]|access-date=2008-05-21|archive-date=2001-10-31|archive-url=https://web.archive.org/web/20011031182400/http://www.space.com/missionlaunches/launches/titan4_dsp_launch_010806.html|url-status=dead}}</ref> a location often used for launch into non-polar orbits.<ref>{{cite web |last1=Rowan |first1=Karen |title=Why Are Rockets Launched from Florida? |website=[[Space.com]] |url=https://www.space.com/8811-rockets-launched-florida.html |access-date=27 April 2022 |date=23 July 2010}}</ref><gallery>
File:First TITAN IV launch from Complex 41 - 14 June 1989.jpg|Titan IV-A
File:Titan IVB Centaur launching ELINTspy satellite.jpg|Titan IV-B
</gallery>

==Titan V concept==
{{Redirect|Titan V|the graphics card by [[Nvidia]]|Volta (microarchitecture)}}
The Titan V was a proposed development of the Titan IV, that saw several designs being suggested. One Titan V proposal was for an enlarged Titan IV, capable of lifting up to {{convert|90000|lb}} of payload.<ref>{{cite book|last=Hujsak|first=Edward|title=The Future of U.S. Rocketry|year=1994|publisher=Mina-Helwig Company|location=La Jolla, CA|isbn=978-1-8861-3301-3|page=44}}</ref> Another used a cryogenic first stage with [[Liquid rocket propellant|LOX/LH2]] propellants;<ref>{{Cite web|url=http://www.astronautix.com/t/titan5.html|archive-url=https://web.archive.org/web/20161228054529/http://astronautix.com/t/titan5.html|url-status=dead|archive-date=December 28, 2016|title=Titan 5|website=www.astronautix.com}}</ref> however the [[Atlas V]] [[National Security Space Launch|EELV]] was selected for production instead.

==Launch vehicle retirement==
Most of the decommissioned Titan II ICBMs were refurbished and used for Air Force space launch vehicles, with a perfect launch success record.<ref>{{cite web|url=https://www.spacedaily.com/news/milspace-comms-03zj.html|title=Final Refurbished Titan II Missile Launches Defense Weather Bird|access-date=April 25, 2021|date=October 19, 2013|publisher=Space Daily}}</ref>

For orbital launches, there were strong advantages to using higher-performance [[liquid hydrogen]] or RP-1 fueled vehicles with [[liquid oxygen]]; the high cost of using hydrazine and nitrogen tetroxide, along with the special care that was needed due to their toxicity, were a further consideration. [[Lockheed Martin]] decided to extend its [[Atlas (rocket family)|Atlas]] family of rockets instead of its more expensive Titans, along with participating in joint-ventures to sell launches on the Russian [[Proton rocket]] and the new [[Boeing]]-built [[Delta rocket|Delta IV]] class of medium and heavy-lift launch vehicles. The Titan IVB was the last Titan rocket to remain in service, making its penultimate launch from Cape Canaveral on 30 April 2005, followed by its final launch from Vandenberg Air Force Base on 19 October 2005, carrying the USA-186 optical imaging satellite for the National Reconnaissance Office.{{citation_needed|date=July 2019}}

==See also==
*[[Titan Missile Museum]]
*[[List of Titan launches]]
*[[Comparison of orbital launchers families]]
*[[Comparison of orbital launch systems]]
*[[1980 Damascus Titan missile explosion|Titan site 374-7 explosion]]

==Notes==
{{Reflist|2}}

==References==
* 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}}
* USAF Sheppard Technical Training Center. "Student Study Guide, Missile Launch/Missile Officer (LGM-25)." May 1967. pp.&nbsp;61–65. Available at WikiMedia Commons: TitanII MGC.pdf
* Larson, Paul O. "Titan III Inertial Guidance System," in AIAA Second Annual Meeting, San Francisco, 26–29 July 1965, pp.&nbsp;1–11.
* Liang, A.C. and Kleinbub, D.L. "Navigation of the Titan IIIC space launch vehicle using the Carousel VB IMU". AIAA Guidance and Control Conference, Key Biscayne, FL, 20–22 August 1973. AIAA Paper No. 73-905.
* Stumpf, David K. ''Titan II: A History of a Cold War Missile Program.''  The University of Arkansas Press, 2000. {{ISBN?}}

==External links==
{{Commons|Titan (rocket)}}
*[https://web.archive.org/web/20160907152809/http://www.astronautix.com/t/titan.html Titan history] at astronautix.com – includes chronology of launches and variants
*[https://archive.org/details/1963-11-14_Space_Movie Footage of November 1963 launch of Titan II] at archive.org  (b/w; 0m59s; includes early use of 'rocket cam' technology)
*{{YouTube|id=nGoQEW2Rhwg|title=Titan III Research and Development – 1967 US Air Force Educational Documentary}}  (color; 13m33s)
*[https://fas.org/nuke/guide/usa/icbm/sm-68.htm Titan I] at fas.org ([[Federation of American Scientists]])
*[https://fas.org/nuke/guide/usa/icbm/sm-68b.htm Titan II] at fas.org
*[https://fas.org/spp/military/program/6555th/6555c3-6.htm Titan history] at fas.org
*[http://www.encyclopediaofarkansas.net/encyclopedia/entry-detail.aspx?entryID=2543 Explosion at 374-7] – Details of the September 1980 Arkansas silo explosion
*[http://antwrp.gsfc.nasa.gov/apod/ap051027.html Photo of the last Titan launch], at the [[APOD]] archive

{{Titan rockets}}
{{USAF space vehicles}}
{{Rocket families}}
{{Orbital launch systems}}
{{Lockheed Martin}}
{{USAF system codes}}
{{Authority control}}

{{DEFAULTSORT:Titan (Rocket Family)}}
[[Category:Titan (rocket family)| ]]
[[Category:Rocket families]]
[[Category:Intercontinental ballistic missiles of the United States]]
[[Category:Cold War weapons of the United States]]
[[Category:Nuclear weapons of the United States]]
[[Category:Military space program of the United States]]
[[Category:NASA space launch vehicles]]
[[Category:Lockheed Martin space launch vehicles]]