The hypersonic X-51A WaveRider belongs to the US military and uses a revolutionary ‘scramjet’ engine to reach 4,500mph within seconds.
Today the cutting-edge craft will be dropped from a B52 bomber over the Pacific Ocean in its latest test.
It will be flown from Edwards Air Force Base in the Mojave Desert in California, attached to the bomber’s wing.
The jet will then be dropped from almost 50,000ft near the Point Mugu promontory. A rocket booster will ignite and speed it up to about Mach 4.5 and, if all goes well, the aircraft’s engine will take over from there, pushing the speed to more than Mach 6 and lifting the craft to 70,000ft.
The mission will last 300 seconds – the longest the craft has ever flown to date. After the historic test, the plane will crash into the sea, and there are no plans to recover it.
Hypersonic flight – which relates to speeds of more than five times the speed of sound – is seen as the next step for aircraft. ‘Attaining sustained hypersonic flight is like going from propeller-driven aircraft to jet aircraft,’ Robert Mercier, deputy for technology in the high speed systems division at the Air Force Research Laboratory in Ohio told the Los Angeles Times.
‘Since the Wright brothers, we have examined how to make aircraft better and faster. Hypersonic flight is one of those areas that is a potential frontier for aeronautics. I believe we’re standing in the door waiting to go into that arena.’
The project is being funded by Nasa and the Pentagon, which hope it can be used for military stealth aircraft and new weapons.
The WaveRider programme is estimated to cost £89million, according to Globalsecurity.org, a website for military policy research. It has had a mixed history, with previous tests being aborted after the engine stalled.
Currently the fastest passenger plane in the world is the Cessna Citation X, which has a top speed of 700mph or Mach 0.9, although it takes only seven passengers.