This hypersonic space plane is going to change travel forever

Is it a bird? Is it a plane?

No - it's a SABRE jet, the future of all intercontinental travel that could take you anywhere in the world in four hours. 

BAE Systems (nothing to do with your crush) has announced an investment of £20.6 million in UK company Reaction Engines - who have created a single engine capable of taking an aircraft from a runway to speeds of over five times the speed of sound in the atmosphere.

Once a SABRE-powered aircraft is high enough, it can then switch to a "rocket mode of operation", allowing spaceflight at speeds equivalent to 25 times the speed of sound. Which is really bloody quick.

"But how does it work?!" you may well ponder. We don't really know, but here's a brilliant infographic and video that helps dumb the tech down for those of us without a degree in rocket science.

So, air goes in one end, some science stuff happens (the challenge is keeping air cool - with the SABRE cooling inrushing air to about -140 degrees C in a hundreth of a second), and you travel from London anywhere in the world in four hours.

Four. Hours. 

We'll have to wait though - if everything goes according to plan the first ground-based tests will take place in 2020, and unmanned tests expected in 2025.