X-51 Hypersonic Flight

May 3, 2013 - 5:36 PM
In this Wednesday, May 1, 2013 photo released by the U.S. Air Force, the X-51A Waverider, carried under the wing of a B-52H Stratofortress bomber, prepares to launch for its fourth and final flight over the Pacific Ocean. The X-51A, an experimental, unmanned aircraft developed for the U.S. Air Force, went hypersonic during a test off the Southern California coast, traveling at more than 3,000 mph, the Air Force said Friday. The Air Force has spent $300 million studying scramjet technology that it hopes can be used to deliver strikes around the globe within minutes. (AP Photo/U.S. Air Force, Bobbi Zapka)