An unmanned hypersonic glider developed for U.S. defense research into super-fast global strike capability was launched atop a rocket early Thursday but contact was lost after the experimental craft began flying on its own, the Defense Advanced Research Projects Agency said.
There was no immediate information on how much of the mission's goals were achieved.
The launch from Vandenberg Air Force Base, 130 miles northwest of Los Angeles, was the second of two planned flights of a Falcon Hypersonic Technology Vehicle-2. Contact was also lost during the first mission.
Shaped like the tip of a spear, the small craft is part of a U.S. military initiative to develop technology to respond to threats at 20 times the speed of sound or greater, reaching any part of the globe in an hour.
The HTV-2 is designed to be launched to the edge of space, separate from its booster and maneuver through the atmosphere at 13,000 mph before intentionally crashing into the ocean.
Defense analyst John Pike of Globalsecurity.org wasn't surprised with the latest failure because the hypersonic test flight program is still in its infancy.
"At this early stage of the game, if they did not experience failures, it's because they're not trying very hard," he said.
Pike said it's possible for engineers to still glean useful information about what worked and what didn't, despite the flight ending prematurely. The key is to analyze what happened in the final five seconds before contact was lost.
DARPA used Twitter to announce the launch and status of the flight.
The agency said the launch of the Minotaur 4 rocket was successful and separation was confirmed. It next reported that telemetry — the transmission and measurement of data from the glider — had been lost.
"Downrange assets did not reacquire tracking or telemetry," the agency added. The craft has "an autonomous flight termination capability," it noted.
No further details were immediately reported. There was no immediate response to an email request to DARPA for information on the mission.
The HTV-2 is intended to put theory, simulations and wind tunnel experience to the test in real flight conditions at speeds producing temperatures in the thousands of degrees and requiring extremely fast control systems, according to DARPA.
The first HTV-2 was launched on April 22, 2010. It returned nine minutes of data, including 139 seconds of aerodynamic data at speeds between 17 and 22 times the speed of sound, DARPA said.
That craft detected an anomaly, aborted its flight and plunged into the ocean, the agency said.
The military and NASA have also been working on powered aircraft capable of flying at speeds greater than five times the speed of sound, or Mach 5.
In 2004, NASA's unmanned X-43A reached Mach 9.6 on a flight off California. Powered for 10 seconds by a supersonic combustion ramjet, or scramjet, that set a speed record for jet-powered flight.
The X-43A also set the previous record of Mach 6.8 earlier that year.
The unmanned X-51A Waverider, a demonstrator, developed by the Air Force, DARPA, Pratt & Whitney Rocketdyne and Boeing, has been tested twice.
Powered by a scramjet, the first X-51A reached about Mach 5 for 140 seconds after being dropped from the wing of a B-52 in May 2010, according to Boeing. Last June, a second craft had problems in a flight off the California coast and the test was terminated. Two more flights are planned for the X-51A program.
The HTV-2 was launched atop a Minotaur 4 rocket built by Orbital Sciences Corp. from decommissioned Peacekeeper intercontinental ballistic missiles. The Minotaur 4 made its debut last year carrying the first HTV-2.
"From what we can tell based on preliminary data, it looked like the rocket did its job," said Orbital spokesman Barry Beneski.
Minotaur 4 is part of the Minotaur rocket family. There have been 22 Minotaur launches since 2000 — a 100 percent success rate. The price of a single flight ranges from $15 million to $30 million depending on the rocket style, according to the company.