DARPA has confirmed that it lost contact with the HTV-2 Mach 20 glider yesterday and said it will continue the research.

The Defense Advanced Research Project Agency (DARPA) tried with little success on Thursday to fly its high-speed Hypersonic Technology Vehicle-2 (HTV-2), a mishap the agency chalked up to continued trouble controlling the aerodynamic phase of flight.

Despite the fact that this is the second HTV lost by DARPA, however, officials pledged to carry on with the project.

"We'll learn. We'll try again. That's what it takes," DARPA director Regina Duncan said in a statement. "Filling the gaps in our understanding of hypersonic flight in this demanding regime requires that we be willing to fly."

The aircraft took off and briefly achieved Mach 20 speed, but nine minutes later, . Initial evidence suggests that it "impacted the Pacific Ocean along the planned flight path," DARPA said. The agency said it has gathered an independent engineering review board to examine the data collected during yesterday's flight and advise the agency on how to proceed.

"Here's what we know," said HTV-2 program manager Air Force Major Chris Schulz. "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."

With top speeds of 13,000 miles per hour, the HTV-2 is designed to to fly anywhere in the world in less than an hour, DARPA says. Thursday's flight was DARPA's second failed attempt; it was last tested in April 2010. Takeoff was successful, but DARPA again lost contact with the aircraft after nine minutes and the vehicle was lost somewhere over the Pacific Ocean.

Wired speculated earlier this week that in the event of an unsuccessful flight, DARPA might kill the HTV project. The agency had previously said it had no plans to build a third HTV, but it appears the research will continue.