Ajoint U.S. Air Force and Defense Advanced Research Projects Agency (DARPA) projectis moving speedily along--intended to fly to Mach 20, plus some. TheFalcon Hypersonic Technology Vehicle program is ...

For the second time in a row, the Falcon HTV-2, the unmanned hypersonic glider developed by the Defense Advanced Research Projects Agency (DARPA) for the U.S. defense failed its test flight and got ...