 Initially, this focused on air-launched ballistic missiles, which would be carried aboard aircraft flying far from the Soviet Union, and thus impossible to attack by either ICBM, because they were moving, or long-range interceptor aircraft, because they were too far away.In the shorter term, looking to rapidly increase the number of missiles in its force, Minuteman was given crash development status starting in September 1958.Advanced surveying of the potential silo sites had already begun in late 1957.