US military is planning a hypersonic vehicle that could fly from New York to London at five times the speed of sound.

The proposed hypersonic vehicle is based on the X51-WaveRider, a scramjet engine developed by the Air Force Research Laboratory and Darpa (the US military’s research agency) as part of a $300 million (£200 million) programme to prove the viability of air-breathing, high-speed scramjet propulsion.

Hypersonic flight is five times the speed of sound (Mach 5) and requires a special type of engine that can handle the heat and pressure of hypersonic aerodynamics.

Over the course of the WaveRider project four X-51A cruisers were built and in May 2010 the first X-51A WaveRider made a successful test flight off the coast of South California.

As it is effectively only an engine, it wasn’t capable of flight, so it was attached like a missile to the left wing of a B52 Stratofortress (below).

Military plane flying through blue sky with vehicle attached

When the B52 reached 50,000ft, the WaveRider was released, accelerating using a rocket booster before the engine ignited and it reached speeds of Mach 5.  A vehicle error after 200 seconds caused the flight to be terminated.

The last test flight was undertaken in May 2013, with the fourth X-51A WaveRider travelling 230 miles in just over six minutes – the longest air-breathing hypersonic flight - before it crashed into the ocean.

Check out video of the flight by clicking the arrow in the main picture above.

Air Force Chief Scientist Mica Endsley told that the X-51 was a proof of test concept.

“It showed that you could get a scram jet engine, launch it off an aircraft and it could go hypersonic,” she said.

“It was able to go more than Mach 5 until it ran out of fuel. It was a very successful test of an airborne hypersonic weapons system.”

Vehicle attached to military plane

The team is now planning a new type of hypersonic air vehicle capable of carrying equipment such as guidance systems and weapons. The challenge is to create materials, such as a guidance system, that will withstand the temperature, which they hope to overcome by 2023.

“There are a bunch of technological challenges that have to be addressed to make a functioning system that will work," Endsley said.

She said a flight from New York to Los Angeles could drop in time from 5 hours to 30 minutes.

Having the capability to travel long distances at high speeds makes hypersonic flight a key military technology of the future, with both the US and China testing hypersonic flights.

But don’t start planning your one-hour flight to the Big Apple just yet. Although hypersonic flight is possible, the human body isn’t capable of withstanding the current acceleration speeds.

Video credit: Boeing

Photo credit: Wright Patterson Air-Force Base