Supersonic jet could slash flying times

An international team developing a new type of supersonic jet that would allow air travel at more than eight times the speed of sound said today that a test flight appeared to have succeeded.

A prototype of the scramjet, which uses the rush of oxygen in the air at high speeds to ignite hydrogen fuel, was blasted into the upper atmosphere on a rocket and allowed to plunge back to earth in the south Australian desert.

Researchers said they would have to wait a couple of weeks to marshal all the data before giving an authoritative assessment but the project leader, Dr Allan Paull of the University of Queensland, said: "It was at least a 95% success."

Scientists believe scramjets (short for supersonic combustion ramjet) could one day be used to build aircraft capable of flying from, say, London to Sydney in a few hours, a flight that now takes at least 18 hours.

During today's test, two Terrier Orion Mk-70 rockets blasted the scramjet to an altitude of about 314km (195 miles) before hurtling back to earth.

Just seconds before the rockets slammed into the red dust of the central Australian desert after a scheduled 10-minute flight, the scramjet was supposed to kick into action at a speed of some 8,000 kph (5,000 mph), said project spokeswoman Jan King.

Dr Paull said that it appeared to have worked, and told reporters: "As far as we are aware ... we certainly got in the right trajectory."

Onboard sensors sent flight data back to the researchers on the ground. "We got everything we wanted, we've just got to analyse the data now but it all seemed to basically work," Dr Paull told reporters.

Scramjets can theoretically halve payload weights by carrying only fuel - such as liquid hydrogen - rather than both the fuel and oxygen carried by traditional rockets. That would significantly cut the cost of launching satellites into space.

The international consortium led by Dr Paull's team launched a test in October but it failed when a rocket carrying the experimental jet veered off course and slammed into the desert.

In a scramjet, oxygen from the atmosphere is rammed into the combustion chamber where it spontaneously ignites, but the engine must be traveling at about five times the speed of sound for the process to work. Sound travels at 1,200 kph (744 mph) at sea level.

Source: guardian.co.uk