#OTD 26 May 2010 at Edwards - The X-51A “Waverider” Scramjet Engine Demonstrator vehicle made the longest ever supersonic combustion ramjet-powered hypersonic flight in a the mission performed off the coast of southern California. The approximately 150-second burn by the X-51A’s Pratt & Whitney Rocketdyne-built air breathing scramjet engine accelerated the test vehicle to approximately Mach 4.9. The previous longest scramjet burn in a flight test was 12 seconds. U.S. Air Force officials called t

The X-43A was a small, unmanned test aircraft built by NASA with one goal: to achieve incredible speed. Part of the Hyper-X program, it aimed to prove that a scramjet could operate in real flight, not just inside a wind tunnel. Rather than launching from a runway, the X-43A was carried to high altitude by a B-52, then boosted by a Pegasus rocket to several thousand miles per hour. Only after the booster separated did its scramjet engine ignite. Unlike conventional rockets, the scramjet didn’t ca