The Air Force built the X-51A Waverider to test hypersonic flight, or an aircraft flying more than Mach 5. Air Force officials had hoped the Waverider, which looks like a 25-foot missile, would reach Mach 6, or at least 4,500 miles per hour.
However, the Waverider dropped into the ocean only 15 seconds into its test flight, according to the Air Force. Scientists and engineers had hoped it would fly for 300 seconds. One of the control fins failed causing operators to lose control, the Air Force said in a statement. Investigators will inspect the data collected during the flight and issue a report in about two weeks.
"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 hypersonic aircraft uses scramjet technology to reach such high speeds meaning it doesn't have moving parts and uses oxygen in the air opposed to liquid fuel.
This was the program's last budgeted test. Air Force officials will have to fight for Congressional funding to meet its goal of outfitting an operational aircraft with hypersonic technology by 2016.
Service leaders have said they want to develop the hypersonic capability to either deliver a ballistic missile to anywhere in the world in minutes, or a reconnaissance platform that could fly overhead a special operations team undetectable by radar. No surface-to-air missile defense system is equipped to hit an object moving that fast.
The Waverider program started in 2004 with the military already having spent $140 million on it. The Air Force completed two other tests before Tuesday's in 2010 and 2011. The 2011 test was also considered a failure. In the 2010 test, the Waverider flew for 143 seconds and reached 3,400 miles per hour.