Atlas Combat Units
Although the 564 SMS at Francis E. Warren AFB, WY is often credited as this country’s first operational ICBM squadron, to provide the U.S. with an interim or emergency ICBM capability, in September 1959 the Air Force deployed three SM-65D Atlas missiles on open launch pads at Vandenberg AFB, CA, under the operational control of the 576 SMS, 704 SMW. Completely exposed to the elements, the three missiles were serviced by a gantry crane. Beginning on 31 October 1959, at least one missile was on operational alert at all times. One source says they remained on alert until 1 May 1964. During the interim, SAC deployed 11 operational Atlas ICBM squadrons in other parts of the nation. Each of the three missile variants, the Atlas D, E, and F series, were deployed in progressively more secure launchers. In addition to the open pads at Vandenberg, there were also semi-hardened bunkers that were used for development and testing purposes at that base. Similar facilities were built for the first squadrons at Francis E. Warren AFB, where the 564 SMS was organized on 1 July 1958 (the 576 at Vandenberg was activated three months earlier). The 564 SMS was equipped with six Atlas-D missiles in above-ground launchers. Three additional Atlas-D squadrons, two near F.E. Warren AFB and one at Offutt AFB, NE were also based in above-ground launchers that provided blast protection against slight over-pressures (about 5 psi). These tactical units were: 564 SMS (6 missiles), 565 SMS (9 missiles), and 549 SMS (9 missiles). The first site at Warren for the 564 SMS consisted of six launchers grouped together, controlled by two launch operations buildings, and clustered around a central guidance control facility. This was called the 3×2 configuration: two launch complexes of three missiles each constituted a squadron. At the second Warren site for the 565 SMS and at Offutt for the 549 SMS, the missiles were based in a 3x3 configuration: three launchers and one combined guidance control/launch facility constituted a launch complex, and three complexes comprised a squadron. A dispersal technique of separating the launch complexes by 20 to 30 miles was employed to reduce the risk that one powerful nuclear warhead could destroy multiple launch sites. The Atlas-E missiles were based in horizontal "semi-hard" facilities that protected the missile against over-pressures up to 25 psi. In this arrangement the missile, its support facilities, and the launch operations building were housed in reinforced concrete structures that were buried underground; only the roofs protruded above ground level. These were referred to as “coffin” launchers. The Atlas-E tactical units, each equipped with 9 missiles, were: 567 SMS at Fairchild AFB, WA; 548 SMS, Forbes AFB, KS; and 566 SMS, F.E. Warren AFB, WY. The six ATLAS-F squadrons were the first ICBMs to be stored vertically in underground silos. Built of heavily reinforced concrete, the huge silos were designed to protect the missiles from over-pressures of up to 100 psi. These tactical units, each equipped with 12 missiles, were: 550 SMS, Schilling AFB, KS; 551 SMS, Lincoln AFB, NE; 577 SMS, Altus AFB, OK; 578 SMS, Dyess AFB, TX; 579 SMS, Walker AFB, NM; and 556 SMS, Plattsburgh AFB, NY. Of all these units, only the 579 SMS at Walker was notorious. The squadron's sites developed a bad reputation due to three missile explosions: On 1 June 1963, launch complex 579-1 was destroyed during a propellant loading exercise. On 13 February 1964, an explosion occurred during another propellant loading exercise, destroying launch complex 579-5. Again, a month later, on 9 March 1964, silo 579-2 fell victim to another explosion that occurred during a propellant loading exercise. Thankfully, these missiles were not mated with their warheads at the time of the incidents. And fortunately, the only injury reported was that of a crewman running into barbed wire as he fled the site.