Nasa aims for speed record
2004-11-16 17:42
Washington - Nasa aimed to shatter the world record for aircraft speed on Tuesday with its X-43A hypersonic jet, after the US space agency delayed the scramjet's flight by a day to conduct extra technical checks.
The pilotless supersonic combustion ramjet, or scramjet, was to zoom across the Pacific Ocean on Monday at about 10 times the speed of sound, or Mach 10 - almost 3.2km per second.
But Nasa conducted additional checks on the scramjet's electronic system, leaving no time to launch it within the hours during which it was supposed to fly, said Elvia Thompson, a Nasa spokesperson.
"The navy and the (federal aviation administration) gave us the window between 14:00 and 16:00 pm Pacific time (2200-00:01 GMT) because it's the least number of trans-Pacific flights coming in," Thompson said.
The flight was to take place late on Tuesday, she said.
The small jet will be launched from a B-52B aircraft that will take it over the Pacific.
The scramjet is only 3.65m
long, with a wingspan of 1.5m.
If the test is successful, it will beat the record set in March by another X-43A, which powered up its scramjet engine and performed "flawlessly" for 11 seconds, attaining speeds of seven times the speed of sound, or Mach 7.
The jet uses a new type of engine that burns fuel in a stream of air compressed by the forward speed of the aircraft.
Conventional jet engines use rotating blades to draw in and compress air, and cannot reach supersonic speeds.
Nasa says that scramjets will ultimately provide safer and more affordable high-speed flight in vehicles more like airplanes than rockets.
Unlike rockets, scramjets can be throttled back and flown like an airplane.
Nasa calls it a "high-risk, high-payoff research programme".