UK government has bought a large stake in new 4,000mph engine

We feature a lot of stories about new planes and technology that promise to dramatically cut the time of long haul flights, many of which might never see the light of day. But now the UK government and BAE Systems have invested money into an engine that, it is claimed, would travel from London to Australia in 4 hours, and might make low-cost commercial space travel a reality.

The 'Sabre' engine is being developed by British company Reaction Engines; it is a hybrid rocket and jet propulsion system which, if it lives up to its promises, will reach any point on Earth in four hours or less.

In case you hadn't realised, that's really, really fast.

New plane to fly London-Sydney in 4 hours

A £60million investment from the UK government, and the purchase of 20% of the company by BAE Systems, makes it far more likely that the Sabre engine will become a reality - even if the project is at least a decade away from completion.

The engine is intended to eventually power an aircraft called Skylon, which will cool an incoming airstream from 1,000 degrees C to -150C almost instantly, allowing it to reach nearly 4,000mph in Earth's atmosphere. It's rocket engine will then allow it to escape into orbit.

It's still a long way away, but this could be the beginning of a genuine revolution in travel.