NASA will attempt to break the aircraft speed record next week by flying a jet plane at 7,000 mph, or nearly 10 times the speed of sound, say planners for the agency's experimental X-43A project. The unmanned flight will mark the third time NASA has tested its new supersonic-combustion ramjet, or "scramjet," engine, which has no moving parts and emits only water as exhaust. The first test, in 2001, had to be aborted when the rocket that boosts the small X-43A aircraft to its flying height spun out of control over the Pacific Ocean. The second test, in March of this year, went more smoothly, with the plane reaching a record-breaking speed of 5,000 mph, or nearly seven times the speed of sound. NASA hopes to set a new record with its third flight Monday, when it will try to push the X-43A aircraft to Mach 10, or 10 times the speed of sound. In contrast, most commercial planes fly under Mach 1. Speaking at a press briefing, X-43A program manager Vince Rausch predicted success for Monday's flight. But he cautioned that the experimental nature of the program and the extremely high speeds could lead to unexpected results. "There is risk in this program," he said. "We fully anticipate that we have reduced the risk at these levels, but you're never fully sure." One of the risks is the possible overheating of the X-43A's leading edges -- its nose and the front side of its two tails. During the plane's second flight, air flowing around the aircraft at supersonic speeds heated the leading edges to 2,600 degrees Fahrenheit. Temperatures during the flight next week could go as high as 3,600 degrees, according to lead engineer Laurie Marshall. To compensate, the team has added a special carbide coating to the leading edges and changed the design of the nose, said Marshall. The team has also made minor changes to the scramjet engine based on observations from the second flight.
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go NASA, go!!!
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