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.
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 hypersnic 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 Mr Joel Sitz told a press conference. "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.
Researchers at the NASA Dryden Flight Research Center at Edwards Air Force Base, on the western edge of the Mojave Desert north of Los Angeles, hope the new engine will revolutionize aviation, speeding the development of significantly faster aircraft and lowering the cost of launching payloads.
During the test, a modified B-52 bomber dropped the X-43A at an altitude of around 40,000 feet.
A rocket attached to the 2,800-pound research vehicle then boosted it to an altitude of 95,000 feet, 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, as part of their Hyper-X program.
The vehicle used in the test will not be recovered from the ocean due to the high cost of such an effort.