LGC - 25C Titan II The Titan II is a Intercontinental Ballistic Missile created by the American company Glenn L . Martin Company as an improvement of the earlier HGM - 25 Titan I ICBM , the Titan II can also be used as a space launcher . The Titan II was fully retired in 1987 . History . The Titan II , manufactured by the Martin Company , was a large two - stage , liquid - fueled , rocket - powered ICBM that incorporated significant performance improvements over the earlier model Titan I weapon system . Titan II had more powerful engines ( first stage - 430 , 000 pounds of thrust , second stage - 100 , 000 pounds of thrust , compared to 300 , 000 pounds and 80 , 000 pounds for the Titan I ) , a larger warhead , all - inertial guidance , hyperbolic fuel . and an on - board oxidizer , and the capability of being fired from a hardened underground - silo launcher . Even as the first Titan I missiles were rolling off the assembly line , the United States Air Force was searching for a way to modify the missile to use an oxidizer other than liquid oxygen . Searching for a way to improve the Titan I at a reasonable cost , in January 1959 the Air Force Ballistic Missile Division ( AFBMD - the name was changed from WDD on June 1 , 1957 ) found that with minor modifications Titan I could be modified to use a noncryogenic , storable propellant . That amounted to a major breakthrough , for it enabled the propellant to be stored within the missile itself , thereby permitting the Titan II to be fired in a single minute . Moreover , the new propellant made it possible to launch the missile from within the silo , simplified maintenance , and reduced the risk of accidents . In November 1959 the Department of Defense ( DoD ) authorized the development of the new Titan II ( SM - 68B / LGM - 25C ) and at the same time directed that the Titan I program be discontinued after six squadrons . As planned , Titan II would be a larger , more advanced missile than its predecessor . It would be equipped with an all - inertial guidance system , a - silo launch capability . In June 1960 the Air Force awarded the Martin Company the Titan II contract . Developed in parallel with the Titan I program , the Titan II took shape rapidly . Captive flight tests began in December 1961 , and in February 1963 a Titan II fired from the Air Force Missile Test Center ( AFMTC ) in Florida logged a successful 6 , 500 - mile flight . In October 1957 , Congress authorized the Air Force to deploy four Titan I squadrons . Later that number increased to 12 squadrons , evenly split between Titan I and Titan II . With their 6 , 300 - mile range , the Air Force based the Titan Is between Colorado and Washington state . The Titan Hs , on the other hand , had a 9 , 000 - mile range and could be based farther south . By locating the Titan II bases in Arizona , Kansas , and Arkansas , the Air Force achieved a wider national dispersal pattern . Other factors that affected the location of the Titan launch facilities were population density under the missile ' s projected flight path , and the location of existing bases to provide logistical support . The Titan II was deployed in a 1x9 configuration . Each squadron consisted of nine separate launch facilities , each housing a single missile . Each Titan II silo was directly connected to an underground launch control capsule manned by a missile combat crew of two officers and two airman . The Titan II silos were markedly different from the Titan I launch complexes . Most notably , the Titan II ' s all - inertial guidance system no longer required that the missiles remain tethered to a ground - based guidance system . Instead the Titan IIs were based separately , and each silo was at least 7 miles from its closest neighbor . The Air Force deployed six squadrons of Titan II missiles . Each squadron contained nine missiles , and to save money , the squadrons were grouped in pairs , forming an operational base . All of the logistic and support functions were based at existing SAC bases , and the missiles were located nearby . On the surface , the Titan II launch facilities covered an area of approximately 600 feet by 600 feet . All of the launch facilities were underground . The silo was built of heavily reinforced concrete , and was 147 feet deep and 55 feet in diameter . It was wider than a Titan I silo because the Titan II was designed to be " hot launched " from within the silo . To deflect and channel the exhaust gases , each silo was fitted with a flame deflector at the base and two exhaust ducts that ran up the length of the silo and vented to the surface . Inside the silo there were nine levels of equipment rooms and missile access spaces . The silo was covered with a steel and concrete door that weighed 740 tons and could be opened in 17 to 20 seconds . The silo was connected to the missile control center by a 250 - foot long access tunnel . Between the silo and the launch control center was the blast lock , a single level , heavily reinforced concrete structure containing three rooms . To enter the launch facility the missile crews descended through a 35 - foot deep access portal that opened into the blast lock area . Each end of the blast lock was covered by a pair of large steel blast doors , each weighing 6 , 000 pounds , designed to protect the launch center from either a surface nuclear blast , or the explosion of the missile within the silo . The doors were designed to withstand an overpressure of 1000 psi . The launch control center was a dome - shaped reinforced concrete structure 37 feet in diameter and containing three levels . The three floors within the launch center were suspended from the ceiling to minimize blast shock . These shock mounts were designed to permit a static floor load of 100 psi . The control center provided space for all of the launch control and communications equipment , as well as a mess and sleeping quarters for the 4 - person combat crew . The Air Force had approved the development of the Titan II ICBM in October 1959 . SAC activated the first Titan II squadron on 1 January 1962 and during the next eight months activated five more squadrons . On 8 June 1963 , the 570th Strategic Missile Squadron at Davis - Monthan became the first Titan II unit to achieve operational status . In October 1963 the AFBMD ' s site activation task force turned over the first Titan II strategic missile wing to the Strategic Air Command ( SAC ) . By December 1963 all six Titan II squadrons were on operational alert . Headquarters SAC completed the deployment of the second - generation ICBM weapon system on the last day of 1963 when it declared the sixth and last Titan II unit , the 374th Strategic Missile Squadron at Little Rock Air Force Base , Arkansas , operational . By 1981 , the Titan II weapon system had served the nation for eighteen years , eight years longer than its predicted service life . The system ' s advanced age , combined with three accidents that destroyed two sites and killed four airmen , had cast doubts on its safety and effectiveness . SAC , anticipating a Department of Defense ( DOD ) initiative , began to consider replacement options in October 1980 . One month later , the Senate Armed Services Committee asked the Defense Department to prepare a formal Titan II safety report . SAC ' s replacement options review became the basis for the DOD safety report released in February 1981 . The DOD study acknowledged Titan II ' s significant , albeit declining usefulness in preserving nuclear deterrence , and recommended deactivation of the Titan system as part of the ICBM modernization plan . During the interim , SAC would continue to improve Titan hardware and safety procedures . On 2 October 1981 , Deputy Secretary of Defense Frank C . Carlucci directed the retirement of the Titan II at the earliest possible time . The deactivation program , designated Rivet Cap , formally began with the removal from alert of site 571 - 6 at Davis - Monthan AFB , Arizona , on 30 September 1982 . Titan II deactivation was completed on 23 June 1987 when technicians removed the last Titan II missile from its silo at Little Rock AFB , Arkansas . The era of liquid propellant ICBMs came to a close on 18 August 1987 with the inactivation of the last Titan II wing , the 308th Strategic Missile Wing at Little Rock AFB . Operational Units . Each Titan II ICBM wing was equipped with eighteen missiles ; nine per squadron with one each at dispersed launch silos in the general area of the assigned base . See squadron article for geographic locations and other information about the assigned launch sites .