December 2004

E-Mail This Article Printer-Friendly Version

Gaseous hydrogen - all two pounds of it - propelled NASA’s experimental X-43A air-breathing plane to nearly ten times the speed of sound in the last and fastest of three unpiloted test flights in the agency’s Hyper-X program in mid-November. The plane’s supersonic combustion ramjet (scramjet) engine achieved a speed of Mach 9.8, or 7,000 mph in a flight that lasted only about ten seconds at about 110,000 feet in restricted airspace over the Pacific Ocean. The small 12-foot plane bears an uncanny resemblance to the much bigger National AeroSpace Plane (NASP) concept developed by NASA in the mid-1980s but that was never built (The Hydrogen Letter June 86 - July 93). Riding a Pegasus rocket booster, the X-43A was carried aloft from the Dryden Flight Research Center at Edwards Air Force Base, California, by a B-52b bomber, releasing the rocket-test plane combo at 40,000 feet. The Pegasus then took it up to its intended altitude and speed of around Mach 4 when the scramjet engine was ignited for the short test flight. When the fuel ran out, the test plane was allowed to crash in the sea. Contact: Dryden Public Affairs Office, 661/276-3449.