Phoenix missile hypersonic testing. Close-up of a surplus demilitarized Navy AIM-54 Phoenix air-launched missile mounted on the centerline pylon of a NASA F-15B research aircraft. This is part of the Phoenix Missile Hypersonic Testbed project. The aim of this project was to launch the missiles while flying at speeds of up to Mach 2.0 (twice the speed of sound). The missiles would then accelerate to hypersonic speeds (Mach 5.0 or greater). This was a testbed project only, with a decision on further funding and live test flights not expected until 2008. Photographed on 14 November 2006.