CRI听力:New rocket engine could revolutionize air travel

It may seem like science fiction - hopping on a rocket jet and shooting round the globe in just four hours - but this may one day become a reality.

UK-based Reaction Engines Ltd. recently announced it had secured funding to continue development of its SABRE rocket engine, a new class of aerospace engine.

Alan Bond is the founder of Reaction Engines.

"We're looking at a revolution in transportation equivalent to the jet engine and access to space, access to anywhere in the world within four hours is on the cards." For example, a aircraft carrying 300 passengers could go from Europe to Australia in about four hours, four and a half hours."

Reaction Engines Ltd.'s SABRE engine combines both jet and rocket technologies.

The real innovation is a heat-exchange system which quickly cools air drawn from the outside atmosphere.

The engine's 'pre-cooler' cools air from 1,000 degrees Celsius to minus 150 degrees Celsius as it passes.

This is then burnt with liquid hydrogen fuel in the rocket combustion chamber.

The company says this makes their heat exchange tech extremely lightweight, meaning it can be used in aerospace applications.

The technology is impressive, but that the economic imperatives of air travel will make its development an inevitability.

That is the view of Tilmann Gabriel. He is the Director of Air Transport Aircraft Maintenance Management at the City University London:

"In today's world, no airline is personally - like with the Concorde times, Air France and British Airways in those days - is taking any risks with aircraft that are nice to have, but don't make money. In today's world, the aircraft has to be absolutely commercial, money-making, efficient, and with our new environmental laws, very, very environmentally-friendly."

One potential more short-term application is using the SABRE engine in unpiloted, re-usable space planes which ferry cargo - such as satellites - straight into orbit.

The plane could take off from a runway just like a regular aircraft, use the rocket engine to blast straight into orbit, release its cargo, then return to Earth for a regular runway landing.

Gabriel reminds us that technological advances like this are always slow coming, and it may yet be years before these new planes are put into service.

"Technological developments in aviation are always time-consuming. A conventional aircraft needs about five to six years to be developed and viable and tested, these kind of innovative engines probably need at least that if not more."