The Titan Missile Museum, also known as Air Force Facility Missile Site 8 or as Titan II ICBM Site 571-7, is a former ICBM missile site located south of Tucson, AZ. The underground facilities consist of a three-level Launch Control Center, the eight level silo containing the missile and its related equipment, and the connecting structures of cableways (access tunnels), blast locks, and the access portal and equipment elevator. The complex was built of steel reinforced concrete with walls as much as 8-foot-thick (2.4 m) in some areas, and a number of 3-ton blast doors sealed the various areas from the surface and each other.
The 103-foot (31 m) Titan II missile inside the silo has neither warhead nor has it ever been fueled, allowing it to be safely displayed to visitors. In accordance with a US/USSR agreement, the silo doors are permanently blocked from opening more than half way. The dummy reentry vehicle mounted on the missile has a prominent hole cut in it to prove it is inert. All of the support facilities at the site remain intact, complete with all of their original equipment.
The silo became operational in 1963 and was deactivated in 1982 as part of President Reagan’s policy (announced in 1981) of decommissioning the Titan II missiles as part of a weapon systems modernization program. All operational Titan II silos throughout the country were demolished, including 18 sites around McConnell AFB in Wichita, Kansas, 17 sites near Little Rock AFB, Arkansas (one additional site previously damaged beyond repair in a mishap/non-nuclear explosion) and 17 other sites by Davis-Monthan AFB and Tucson with the exception of this one. It is now a National Historic Landmark.
The Titan II was the largest operational land based nuclear missile ever used by the United States. The missile had one W53 warhead with a yield of 9 Megatons (9,000 kilotons).
The facility’s highest state of alert was November 22, 1963, when President John F. Kennedy was shot. When news of the shooting broke, the keys used to launch the missile were ordered to be placed on the tables at the launch consoles to prepare for a possible launch. The Pentagon did not yet know whether the Soviet Union had committed an act of war. The keys were not, however, placed in their switches.
At launch, orders from the National Command Authority would have specified one of three pre-programmed targets which, for security reasons, were unknown to the crew. The missile base that is now the Titan Missile Museum (complex 571-7 of the 390th Strategic Missile Wing) was at the time of closure, programmed to strike “Target Two”. The missile’s computer could hold up to three targets, and the target selected was determined by Strategic Air Command headquarters. To change the selected target, the crew commander pressed the appropriate button on the launch console. Target 2, which is classified to this day but was assumed to be within the borders of the former Soviet Union, was designated as an impact blast, suggesting that the target was a hardened facility such as a Soviet missile base. Targets could be selected for air or ground burst, but the selection was determined by Strategic Air Command. (stolen from the web)