SAN FRANCISCO, 29 March 2004 — A revolutionary jet engine flew faster than seven times the speed of sound in a high altitude test over the Pacific on Saturday. “It’s been an outstanding, record-breaking day,” lead propulsion engineer Lawrence Huebner told a post-flight briefing.
NASA’s 12-foot-long X-43A research vehicle — resembling a winged surfboard — hit slightly over Mach 7, about 5,000 mph (8,000 km/h), during 11 seconds of powered flight before gliding at hypersonic speeds for several minutes and finally plunging into the ocean.
The test, conducted off the southern California coast, marked the first time that a “scramjet,” or supersonic-combustion ramjet, has powered a vehicle at such high speed.
“The ramjet-scramjet is the Holy Grail of aeronautics in my mind,” project manager Joel Sitz told the briefing. “If you go from ground to space, you need to use a ramjet-scramjet if you’re going to do it in the most efficient way you can.”
Rather than carrying both the fuel and oxygen needed to provide acceleration, like a conventional rocket engine does, scramjet engines carry only hydrogen fuel and pull the oxygen needed to burn that fuel from the atmosphere.
During Saturday’s test, a modified B-52 bomber dropped the X-43A at an altitude of around 40,000 feet (12,192 meters). A rocket attached to the 2,800-pound (1,270-kg) research vehicle then boosted it to an altitude of 95,000 feet (30,000 meters), setting the stage for the scramjet engine test. Later this year, NASA researchers hope to test the engine at Mach 10, or about 7,000 mph (11,265 km/h), as part of their Hyper-X program.
