The Defense Advanced Research Projects Agency has finished captive-carry tests of Lockheed Martin and Raytheon's unique variants of the Hypersonic Air-breathing Weapon Concept, paving the way for the first free-flight demonstrations later this year. "Completing the captive-carry series of tests demonstrates both HAWC designs are ready for free flight," Andrew Knoedler, HAWC program manager, said in a DARPA press release Tuesday. "These tests provide us a large measure of confidence -- already well informed by years of simulation and wind...