The Pegasus booster fires into the sky with X-43A. Credit: NASA/Jim Ross

NASA's successful X-43A hypersonic research aircraft flight resulted in a treasure trove of scramjet data.

The initial data review, conducted on March 31, confirmed high-fidelity flight data was obtained throughout the vehicle's boost, stage separation and descent to splash down.

"The data clearly shows, and without question, that scramjets work," said X-43A chief engineer Griff Corpening of NASA's Dryden Flight Research Center (DFRC), Edwards, Calif. "But we did see a couple of areas that differed from what was seen in the wind tunnels, thus reinforcing the need for flight testing," he said.

Some significant aviation milestones occurred during this combined effort by NASA's Langley Research Center (LaRC), Hampton, Va., DFRC, and their industry partners. The milestones included the first controlled accelerating flight at Mach 7 under scramjet power; the first air breathing scramjet-powered free flight; and the first successful stage separation at high dynamic pressure of two non-axisymmetric vehicles.

The flight also set a new aeronautical speed record. The X- 43A reached more than Mach 7, approximately 5,000 mph. That was faster than any known aircraft powered by an air- breathing engine has ever flown.

"We flew very closely to how we predicted we would fly in terms of Mach, dynamic pressure, vehicle angle of attack, vehicle yaw, and vehicle roll," Corpening said.

The March 27 flight from DFRC began with NASA's B-52B launch aircraft carrying the X-43A to the test range over the Pacific Ocean off the California coast. A modified Pegasus rocket boosted the X-43A to its test altitude of about 95,000 feet. It separated from the booster and flew freely under its own power. The vehicle landed in the Pacific Ocean at the end of the test. Planning is underway for the next flight this fall at Mach 10, approximately 7,500 mph.

LaRC and DFRC conduct the Hyper-X program. ATK GASL in Tullahoma, Tenn., built the vehicle and the engine. Boeing Phantom Works in Huntington Beach, Calif., designed the thermal protection and onboard systems. Orbital Sciences Corp. Chandler, Ariz. built the modified Pegasus rocket booster.