by Robert Beckhusen and Noah Shachtman | Aug 15, 2012 | Monitor
The Air Force’s X-51A Waverider hypersonic missile attached to the wing of a B-52 Stratofortress. Photo: USAF Updated 2:39 p.m. ET A crucial test for the Air Force’s experimental Mach 5 missile has ended in failure, according to the Air Force....