There are plans to start running test flights of the ‘hypersonic’ jet in the mid-2020s.

Developers are working on a “hypersonic” jet engine that could see commuters flying from Sydney to London in four hours, and London to New York in one. It’s called a SABRE—that is, Synergetic Air Breathing Rocket Engine—and it allows planes to hit speeds of Mach 5.4 (6400 kilometres per hour). Hence the “hypersonic” moniker: whereas “supersonic” refers to a rate of travel that simply exceeds the speed of sound, “hypersonic” speeds typically exceed it five or six times over.

The hybrid hydrogen-oxygen engine is also way greener and cheaper than current air travel, The Telegraph reports, and will give aircraft the potential to fly in space.

“[SABREs] are simply going to revolutionise the way we travel around the globe, and into orbit,” said the engine’s developer, UK-based aerospace manufacturer Reaction Engines. “SABRE can be scaled in size to provide different levels of thrust for different applications which is crucial to our success—it’s going to enable a whole generation of air and space vehicles.”

It’s thought that the hybrid jet engine will allow for the development of so-called spaceplanes—vehicles that can fly like aircraft in Earth’s atmosphere and move like spacecraft in the vacuum of space—which will be able to take off horizontally, hit eye-watering speeds for intercontinental commuting, and switch to rocket mode for space travel at a whopping Mach 25 (30,000 kilometres per hour).

It’s still very much in the trial stage, but the Reaction Engines team reportedly hopes to get test flights off the ground in the next five or six years, with the view of commencing commercial flights some time in the 2030s.

“The main thing with SABRE is it’s like a hybrid of a rocket engine and an aero engine, so it allows a rocket to breathe air,” Reaction Engines’ Shaun Driscoll told the UK Space Conference earlier this week. “Rockets really haven’t progressed in 70 years, whereas aero engines have become very efficient. So, if you can combine an aero engine and a rocket you can have a very lightweight efficient propulsion system and basically create a spaceplane.

“The physics checks out but the challenge is building a test regime.”

Via Vice.com