Pentagon’s hypersonic Falcon aircraft fails “last shot” test flight over Pacific

An arrow-shaped aircraft being developed by the U.S. military to fly at 20 times the speed of sound plunged prematurely into the Pacific Ocean during a test flight on Thursday.

The crash, a costly blow to the Pentagon's strategic plans for new-generation ballistic missiles, was announced with a tweet from the Defense Advanced Research Projects Agency, or DARPA, the Los Angeles Times reported.

"Range assets have lost telemetry," the agency posted on Twitter, meaning ground teams had lost touch with the aircraft, known as Falcon Hypersonic Technology Vehicle 2.

Thursday morning's flight from Vandenberg Air Force Base was the Falcon's second test failure, with both ending in similar circumstances after the early phases appeared to go well.

Project manager Air Force Major Chris Schulz said he believed a solution could be found, but time may be running out for the program amid spending cuts and a moribund economy.

"Here's what we know: We know how to boost the aircraft to near space. We know how to insert the aircraft into atmospheric hypersonic flight. We do not yet know how to achieve the desired control during the aerodynamic phase of flight. It's vexing; I'm confident there is a solution. We have to find it," he said.

Built by Lockheed Martin Corp. from carbon composite material, the Falcon has reached speeds of Mach 20 meaning it could zap between Los Angeles and New York in less than 12 minutes, The Los Angeles Times reported.

One of the considerations for engineers is the extreme surface temperatures generated during flight, which are high enough to melt steel.

DARPA has only built two test prototypes and there are no plans for any more, meaning Thursday's flight was a "last shot" before the program is considered for the scrap heap, the Guardian reported.

Development of the unpiloted aircraft started in 2003 and has cost about $320 million.