The X-51A Waverider was designed to reach Mach 6, or 3,600 mph, after being dropped by a B-52 bomber off the Southern California coast on Tuesday. Engineers hoped it would sustain its top speed for five minutes, twice as long as an X-51A has gone before.
But the Air Force said Wednesday that a faulty control fin prevented it from starting its exotic scramjet engine and it was lost.
The Waverider was built by a consortium of Boeing, the U.S. Air Force, DARPA, NASA, and Pratt & Whitney Rocketdyne.
"It is unfortunate that a problem with this subsystem caused a termination before we could light the scramjet engine," Charlie Brink of the Air Force Research Laboratory at the Wright-Patterson Air Force Base in Ohio, said in a statement.
The Waverider successfully detached from the B-52 and fired the rocket booster as planned. Then its scramjet engine was supposed to take over as it attempted to climb to Mach 6. But that never happened. Fifteen seconds after separating from the rocket booster, the Waverider lost control, preventing a test of the scramjet engine.
"All our data showed we had created the right conditions for engine ignition and we were very hopeful to meet our test objectives," Brink said.
The Pentagon has been testing hypersonic technologies in hopes of delivering strikes around the globe within minutes.
It was the latest failure for the Waverider program. A test flight last year ended prematurely with an X-15A trying to restart its engine until it plunged into the Pacific Ocean.
During the first flight of an X-51A in 2010, it reached near five times the speed of sound for three minutes.
There's only one X-51A vehicle left. The Air Force has not decided whether it will fly.
More Nation & World Headlines
Facebook hit billion-user milestone Monday Last woman still in Ranger School advances Former prep school student convicted of sex charges Stunt pilot dies in crash ahead of New York air show Teacher defuses incident with pistol-packing 14-year-old Can federal workers be fired for adultery site visits? ‘School meals are healthier now than ever before’ Pakistan could have 350 nuclear weapons in 5-10 years
Our new comment system is not supported in IE 7. Please upgrade your browser here.