Design changes by the military complicated the Schilling project and doubled the eventual cost. Safety issues were also a concern. Ironically the Atlas missiles were becoming obsolete almost as fast as they could be installed. Each missile required around an hour of fueling by hand before launch. Also, military commanders worried that the blast of the missile would shake apart the concrete silo that encased it. However these concerns were not passed on to the public nor, probably, to the civilian contractors. Here, Edmund W. Littlefield (left), Utah Construction & Mining's new president, tours the Schilling facility with a military officer. In April 1961, the 550th Strategic Missile Squadron was activated at Schilling Air Force Base, along with a sister squadron at Lincoln, Nebraska. This marked the first "standing up" of Atlas F units, which along with the squadron became operational in 1962. When the base closed in 1965, responsibility for the missile launching sites shifted to Warren Air Force Base.