Experimental scramjet goes record: ten times speed of sound

Australian and U.S. scientists successfully tested an experimental air-breathing supersonic combustion engine that one day could lead to extremely fast flights around the world.

Defense scientists from Australia’s Defense Science and Technology Organization and United State’s Defense Advanced Research Projects Agency (DARPA) developed the scramjet and tested it using an conventional rocket that lifts it into the thin atmosphere high above commercial airplane traffic before the scramjet engine is ignited.

The hypersonic test rocket was flown above the Woomera range in outback South Australia. It lifted off for its flight just after noon ACST (Australia Central Standard Time). Its peak altitude was 330 miles (530 kilometers).

Reaching Mach 10, or about 11,000 kilometers (6,835 miles) per hour, was a great success for the scientists whose goal is to develop a hypersonic airplane in the near future for space travel and for travel about the Earth. This flight is considered the first time that a combustion engine has achieved Mach 10.

Mach (or Mach speed) is the speed of an object as a multiple of the speed of sound. For example, Mach 2 is the speed a vehicle is going when traveling at twice the speed of sound. In the medium of air, the speed of sound is approximately 1,129 feet (344 meters) per second.

A scramjet (short for “supersonic combustion ramjet") is similar to a ramjet, except that the flow in the combustor is at supersonic speeds (or speeds exceeding the speed of sound).

A ramjet is a type of jet engine in which its fuel is burned in a duct with air compressed by the forward motion of the jet. A simple ramjet uses an intake for air, a combustor for fuel, and a nozzle for exhaust.

Scramjet engines are theorized to be capable of reaching between Mach 12 and Mach 24. The fastest conventional air-breathing vehicles, such as Lockheed's SR-71 ("Blackbird"), travel at about Mach 3.2. NASA Apollo rockets went faster than Mach 30.

An operational scramjet engine would have both civilian and military applications. The launching of satellites could be done more economically. Commercial flights from Sydney, Australia to London, England—about 10,500 miles (17,000 kilometers)—would be possible in less than two hours.

Source: Iwire