scramjet

Researchers for Australian and U.S. defense agencies said Friday they tested an experimental jet engine at speeds of up to 6,835 miles per hour--10 times the speed of sound. The tests were conducted over the Australian outback using an air-breathing supersonic combustion "scramjet" engine, which, because it operates properly only at high speeds and in thin air, must first be propelled into the earth's upper atmosphere by a rocket. The engine then takes over, pushing the vehicle to hypersonic speeds.

June 15, 2007 6:44 AM PDT

Photo by: Defence Science and Technology Organisation