X-51 Waverider makes historic hypersonic flight: "An X-51A Waverider flight-test vehicle successfully made the longest supersonic combustion ramjet-powered hypersonic flight May 26 off the southern California Pacific coast.
The more than 200 second burn by the X-51's Pratt & Whitney Rocketdyne-built air breathing scramjet engine accelerated the vehicle to Mach 5. The previous longest scramjet burn in a flight test was 12 seconds in a NASA X-43.
Air Force officials called the test, the first of four planned, an unqualified success. The flight is considered the first use of a practical hydrocarbon fueled scramjet in flight.
'We are ecstatic to have accomplished most of our test points on the X-51A's very first hypersonic mission,' said Charlie Brink, a X-51A program manager with the Air Force Research Laboratory at Wright-Patterson Air Force Base, Ohio. 'We equate this leap in engine technology as equivalent to the post-World War II jump from propeller-driven aircraft to jet engines.'
The X-51 launched at about 10 a.m. from here, carried under the left wing of an Air Force Flight Test Center B-52 Stratofortress. Then, flying at 50,000 feet over the Point Mugu Naval Air Warfare Center Sea Range, it was released. Four seconds later an Army Tactical Missile solid rocket booster accelerated the X-51 to about Mach 4.8 mach before it and a connecting interstage were jettisoned. The launch and separation were normal, Mr. Brink said.
Four X-51A cruisers have been built for the Air Force and the (Defense Advanced Research Projects Agency) by industry partners Pratt & Whitney Rocketdyne and Boeing.
Air Force officials intend to fly the three remaining X-51A flight test vehicles this fall, Mr. Brink said."
