A futuristic hypersonic passenger plane that could carry 300 passengers at five times the speed of sound—more than 3,000 mph—is already on the drawing board in Britain. The A2, whose design is funded by the European Space Agency, could be in the air in 25 years if there is a demand, reports the Guardian. It's even environmentally friendly, running on a green fuel, liquid hydrogen.
But one caveat to claustrophobic passengers: the aircraft won't have windows. The airline could shrink the flight time from Brussels to Australia from 18 hours to just 4 hours and 40 minutes. "It sounds incredible by today's standards, but I don't see why future generations can't make day trips to Australasia," said an exec at designers Reaction Engines. (Read more hypersonic plane stories.)