Scramjet Success - AFRL/Boeing X-51A flies at Mach 5.1
The US Air Force Research Laboratory's Boeing X-51A WaveRider unmanned vehicle achieved the longest air-breathing hypersonic, scramjet-powered flight on its May 1 fourth test flight, flying for 3.5 minutes on supersonic-combustion ramjet power and reaching a maximum speed of Mach 5.1.
