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). 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 a ground burst, 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. Tourist attractions The Titan Missile Museum is located at 1580 West Duval Mine Road, Sahuarita, on I-19. A visitor center for the site features a gift shop, a small museum and guided tours of the site. The museum is intended to put the Titan II within the context of the Cold War. Paid tours are available for hire, offering education about the history of the Titan II site and program, as well as a closer look at many features of the complex. Relics include hardstands for fuel storage containers and the associated control vehicles, restored engines from a Titan II missile, and a re-entry vehicle. Tours below ground may include the control room, the cableways (tunnels), the silo, antenna tower and more. More information can be found and reservations may be made via the museum website. Several times each month, a more extensive "top to bottom" tour is available. This tour takes up to 5 hours and accommodates a maximum of six people. Prior reservations required. The top-to-bottom tour is not handicapped accessible. Several scenes in the 1996 film Star Trek: First Contact were shot at the site. The missile itself was depicted as the launch vehicle for the film's Phoenix spacecraft, the first warp prototype. Gallery See also Missile launch facility Minuteman Missile National Historic Site Strategic missile forces museum