A hypersonic plane with the potential to cut journey times from London to New York to an hour is set to be tested by the US military.
The X-51A WaveRider can travel faster than five times the speed of sound - around 4,500mph - using a "scramjet" engine.
A B52 bomber will carry the WaveRider to 50,000 feet before it is dropped from beneath the wing. A rocket booster will then blast the craft up to around 3,4000mph.
The plane will then fire up the scramjet engine for a total of five minutes before it drops into the Pacific Ocean. The wreckage will not be recovered.