Usable Demonstrators:

Boeing happens to be working on two hypersonic missile projects that could be adapted to arm a next-generation bomber, noted George Muellner, Boeing’s Advanced Systems president. One is the HyFly, a Navy/DARPA scramjet-powered missile project which will fly in about a year. The other is the X-51, an Air Force project in which a rocket boosts a scramjet to ignition speed. Either could take the “advanced technology demonstrator” route, Muellner said, in which an experimental system is made available for operational use. The Predator and Global Hawk UAVs and the E-8 Joint STARS were all ATDs that became operational systems.