The Defense Advanced Research Projects Agency announced that their hypersonic HTV-2 test aircraft crashed during an August 11 flight test, but not before demonstrating that it could maintain control at twenty times the speed of sound — for three minutes, at least.
DARPA’s unmanned prototype Falcon Hypersonic Technology Vehicle 2 (HTV-2) was launched from Vandenberg AFB in California, and was propelled above the atmosphere by a Minotaur IV rocket. The HTV-2 then proceeded to glide along it’s planned course over the Pacific Ocean, but encountered a still-unidentified anomaly nine minutes into the mission, prompting the craft’s automated systems to ditch the plane in a controlled splashdown.
This launch was HTV-2’s second test flight, following an earlier test where the vehicle had lost control, and also had to be aborted. "HTV-2 demonstrated stable, aerodynamically controlled Mach 20 hypersonic flight for approximately three minutes," explains DARPA director Regina Dugan. "We do not yet know the cause of the anomaly for Flight 2."
The HTV-2 is a testbed used to develop and demonstrate control systems for unmanned hypersonic aircraft. It is part of DARPA’s FALCON Project, itself a part of the Prompt Global Strike program, in an effort to develop a Hypersonic Cruise Vehicle (HCV), capable of launching from the United States, and being able to deliver a payload anywhere in the world within one hour. DARPA has announced that they do not plan to conduct a third test flight of the HTV-2, as they feel they have collected enough data from the earlier two flights for their purposes.