Image to right: The second X-43A and its modified Pegasus booster rocket accelerate after launch from NASA's B-52B launch aircraft over the Pacific Ocean.

The Hyper-X program's X-43A was the first, powered hypersonic research aircraft designed, built, flight-qualified, and flight-tested since the rocket-powered X-15's in the 1950s. The X-43A was distinctive in its blending of an airframe with a scramjet or supersonic combustion ramjet engine. A scramjet uses oxygen from the atmosphere, operates more like an airplane, and offers more flexibility and safety than rockets for ultra high-speed flights within the atmosphere and for the first stage to Earth orbit. An unpiloted flight test of the X-43A in March 2004 set a new aeronautical speed record of Mach 6.83—nearly 5,000 mph. A second unpiloted flight in November 2004 resulted in a second speed record of Mach 9.68—nearly 7,000 mph. Both flights have been certified by Guinness World Records as setting the fastest speed records by jet-powered aircraft. Ultimately, the true prize is the knowledge gained of new technology that will allow aircraft to reach supersonic speeds while retaining subsonic maneuverability.

Hyper-X Program Team
NASA Langley Research Center, NASA Dryden Flight Research Center, NASA Headquarters, Allied Aerospace Industries, The Boeing Company, Orbital Sciences Corporation