Jet flies seven times faster than sound
Reuters, San Francisco
A revolutionary jet engine has flown faster than seven times the speed of sound in a high altitude test over the Pacific, marking what NASA scientists hailed as a milestone in developing the "Holy Grail" of space travel."It's been an outstanding, record-breaking day," lead propulsion engineer Lawrence Huebner told a post-flight briefing on Saturday. Nasa's 12-foot-long X-43A research vehicle -- resembling a winged surfboard -- hit slightly over Mach 7, about 5,000 mph, 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.
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The modified Pegasus rocket ignites moments after being dropped from a B-52 bomber over the Pacific Ocean yesterday, accelerating the X-43A pilotless plane to a world speed record of 7,700 km an hour. PHOTO: AFP |
