The Defense Advanced Research Projects Agency's two high-profile hypersonic weapon technology efforts -- one a boost-glide vehicle the other an air-breathing missile -- are both "going well" despite an apparent delay in planned first flight tests, according to the Pentagon's top technology official. Mike Griffin, under secretary of defense for research and engineering, declined during an online event hosted by the Washington Space Business Roundtable on May 20 to disclose what the current estimate is for flight tests of the...
