SABRE Engine: Skylon spaceplane's revolutionary engine passes key milestone

Illustration of the Skylon spaceplane powered by SABRE engines. 

Credit: REL/Adrian Mann

A revolutionary new air-breathing rocket engine designed to propel a spacecraft to orbit in a single stage has passed a critical milestone.

The engine could also revolutionise air travel, reducing journey times around the planet to under 4 hours.

The engine, called SABRE, is a hybrid of a jet engine and a rocket engine. An aircraft fitted with the engines could fly to other side of the planet in under 4 hours travelling at Mach 5.5. more than five times the speed of sound, whilst a spaceplane such as Skylon could be propelled into orbit in a single stage.

The engines breathe in air as they pass through the atmosphere, meaning the spaceship could launch without a fully laden fuel load.

However, the challenge of the design has been how to cool the huge amount of air it continuously breathes in without the engine freezing up.

The testing has proved that SABRE's pre-cooler heat exchangers can cool air from over 1,000⁰C to minus 150⁰C in less than 1/100th of a second without the engine frosting up.

The UK company which invented the new propulsion technology, Reaction Engines Limited (REL) described the successful testing as "the biggest breakthrough in aerospace propulsion technology since the invention of the jet engine".

REL has also devised a spaceplane called Skylon that would be fitted with the SABRE engines. Skylon would take off and land on runways, and would not require any part of the craft to be jettisoned during its journey to orbit.

This would make it a completely reusable spacecraft which could reduce the time and cost of launching payload into space.

REL believe the cost of launching satellites could be cut by 90% if the SABRE powered Skylon entered service.



The UK Space Agency asked experts from the European Space Agency (ESA) to validate the pre-cooler heat exchanger test results

ESA experts who reviewed the testing concluded "The pre-cooler test objectives have all been successfully met and ESA are satisfied that the tests demonstrate the technology required for the SABRE engine development."

The SABRE engine has the potential to revolutionise our lives in the 21st century in the way the jet engine did in the 20th Century. This is the proudest moment of my life. Alan Bond, REL

Illustration of the SABRE engine with the location of the pre-cooler heat exchanger highlighted in blue. Credit: REL/Adrian Mann