I stumbled upon this really interesting article on CNN... It's really interesting.

SYDNEY, Australia (Reuters) -- Australian researchers said an air-breathing hypersonic "scramjet" engine had successfully achieved supersonic ignition in the atmosphere for the first time -- reaching 7.6 times the speed of sound.

Project leader Allan Paull said Friday data analyzed from the July 30 test showed the engine, which uses oxygen in the atmosphere to ignite hydrogen fuel, had reached Mach 7.6 -- a speed that would dramatically cut long-haul flight times around the world.

"We do believe we achieved supersonic flight for the first time," Paull, who heads the University of Queensland "HyShot" programme, told Reuters after his team had finished analyzing the results from the experiment.

Engineers say any commercial application is still years down the road but the successful test of the HyShot scramjet at least proves the technology is viable.

The test over the central Australian desert of the air-breathing engine capable of speeds in excess of 5,000 km (3,100 miles) per hour was the first time engineers had managed to make a scramjet work in flight, outside an air tunnel.

The team fired the scramjet engine into the sky on back of Terrier Orion Mk70 rocket, which took it into the upper atmosphere.

The engine kicked into action on the way back down at 35 kilometers (22 miles) above the earth, with data transmitted by radio until it began to burn up.

NASA tests failed
A year ago, U.S. space agency NASA's test of its multimillion dollar, unmanned X-43A scramjet prototype failed and a previous attempt by the HyShot crew went awry when a rocket used to launch the engine span out of control.

A dream of aviation researchers for decades, scramjets, or supersonic combustion ramjets, could one day allow aircraft to travel from London to Sydney in just two hours compared with more than 20 now -- making in-flight movies obsolete.

But their first commercial application is more likely to be in satellite launching as they do not need to carry as much fuel with them as conventional rockets since they use the oxygen already in the atmosphere to ignite the hydrogen.

The extra payload potential could dramatically slash satellite launch costs.

Paull said the data analyzed from the July 30 test indicated the engine had reached Mach 7.6, or 7.6 times the speed of sound.

"We received data for the full length of the 10-minute flight," he said.

Low cost
At a cost of just A$1.5 million ($810,000), the success came relatively cheaply compared with the tens of millions of dollars NASA has been investing in its prototype.

NASA's scramjet was mounted on an aircraft whereas the HyShot scramjet engine was launched into the atmosphere on a rocket and plummeted back down to earth. The scramjet itself burned up at around 20 kilometer (12.4 miles) above sea level.

The HyShot project was funded by defence authorities from several countries, including Australia, Britain, the United States and Japan.

The University of Queensland said it hoped funding could now be found for continuing research into scramjets but it feared the success of HyShot could lead to the next stage of experiments being taken overseas where research pockets are deeper.

"Australia has proved we can develop this technology at a fraction of the cost of overseas programmes," university vice chancellor John Hay said in a statement.

"We must now build on success and secure the programme in Australia so the intellectual property is not lost to the country," he added.


http://www.cnn.com/2002/TECH/science...eut/index.html