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.