The US Air Force said it was looking to launch its 14-foot long X-51A Waverider on its first hypersonic flight test attempt May 25. The unmanned X-51A is expected to fly autonomously for five minutes, after being released from a B-52 Stratofortress off the southern coast of California. The Waverider is powered by a supersonic combustion scramjet engine, and will accelerate to about Mach 6 as it climbs to nearly 70,000 feet. Once flying the X-51 will transmit vast amounts of data to ground stations about the flight, then splash down into the Pacific. There are no plans to recover the flight test vehicle, one of four built, the Air Force stated.