By Paul J. Richfield
Got a design for a reusable, maneuverable, air-breathing aircraft that can take off and land on a runway and cruise at Mach 6-plus for at least 60 seconds?
The U.S. Defense Advanced Research Projects Agency (DARPA) wants to hear from you.
Working with the Air Force, DARPA is seeking proposals for the Blackswift flight test program, which it envisions as a springboard to future aircraft capable of a wide range of strike and intelligence gathering missions.
“Due to the scope and importance of this program,” DARPA said, “the government has elected to conduct an open competition in order to solicit the best technologies and approaches the aerospace community has to offer.”
Blackswift is expected to employ a wide range of exotic materials and building techniques. Propulsion is straight from science fiction, in the form of a turbine-based combined cycle (TBCC) engine that alters its internal configuration to match the speed range needed in flight.
From takeoff through low supersonic speeds, the TBCC works like a conventional turbojet. After accelerating through Mach 2 or 3, however, the engine morphs into a supersonic combustion ramjet (scramjet), which then takes the aircraft up to Mach 6 and beyond.
Blackswift is expected to build on previous work for Falcon—a joint DARPA/Air Force program with similar mission objectives. Falcon seemed to fall off the fast track last year; however, the Air Force announced its follow-on to the B-2 would be another subsonic stealth bomber.
While the Falcon solicitation was making the rounds, questions arose over whether the aircraft would be manned, unmanned, or optionally manned. The Blackswift query includes a requirement for “autonomous flight control,” which could indicate a preference for an unmanned aerial vehicle.
April 7, 2008