Hypersonic jet could slash flight time from Sydney to London to four hours, say UK Space Agency

TOURISTS could fly from Britain to Australia in just four hours by the 2030s in an aircraft powered by a hypersonic engine being developed in Britain, the head of the UK Space Agency has said.

Reaction Engines, based in Oxfordshire, are building a hybrid hydrogen air-breathing rocket that will propel a plane at Mach 5.4 - more than twice the speed of Concorde - and at Mach 25 in space.

The Sabre engine will slash flight times between London and New York to just an hour - with the hydrogen/oxygen engine far greener and cheaper than current air travel.

The team is running trials on the ground in Denver, Colorado, and hopes to begin test flights in the mid-2020s, before running commercial flights in the 2030s. The Government has invested $US60 million ($88 milllion) in the project, an amount matched by Rolls-Royce, BA systems, and Boeing.

Yesterday, Britain and Australia agreed to work on a "space bridge" partnership. Graham Turnock, head of the UK Space Agency, said: "When we have brought the Sabre rocket engine to fruition, that may enable us to get to Australia in perhaps as little as four hours."

Supersonic commercial flight has not been available since Concorde was scrapped in 2003. Hypersonic - five times the speed of sound - is harder to achieve because of intense engine temperatures. Fighter jets achieve it through a complex cooling system but their engines are large, expensive and inefficient.

The Synergetic Air Breathing Rocket Engine (Sabre) works by using tiny tubes of supercooled helium. Captured heat is also used to power the engine.

The hybrid engine allows a spaceplane to take off horizontally and reach speeds of Mac 5.4 - 6400 km/h for fast commercial travel, and also switch to rocket mode, allowing for space travel at Mach 25 (30,000 km/h).

As well as aerospace, the new engines could be used in the automotive industry and motorsport, or for energy production.