in 1989, reaction engines was created in the u.k. with the purpose of developing an innovative sabre (synergetic air-breathing rocket engine) that would allow aircraft to fly at more than five times the speed of sound and change the access to space travel.

sabre rocket technology. (youtube)

after nearly three decades of research and investments, reaction engines is on the brink of delivering on its promise of sabre, just as tesla ceo elon musk and his space x project as well as amazon ceo jeff bexos and his blue origin project have brought headlines to the race for commercial space travel.

sabre is unique in that it uses “ultra-lightweight heat exchangers,” according to reaction engines’ still in-progress website, that are 100 times lighter than the standard and can cool airstreams from 1,000°c to -150°c in a hundredth of a second.

the system achieves this goal by “breathing.” like a jet engine, sabre takes oxygen from the atmosphere lowering the needs for liquid oxygen on board. the “breathing” portion of the trip is one-fifth of the launch and then a standard rocket mode will get the aircraft into space.

the rocket breathes by combining a turbo-compressor with an air pre-cooler that is positioned behind the inlet cone. the pre-cooler cools compressed air that is then fed into the combustion chamber to be ignited by liquid hydrogen. there is a high pressure ratio between the engine and the combustion chamber leading to hypersonic speeds and altitudes.

as a report in the financial times notes, the process requires “no jettisoning of parts and the aircraft should be able to return to earth and repeat the trip.”

learn more in this video explaining the sabre technology: