The Register: The Defense Advanced Research Projects Agency (DARPA) has thrown its new "Blackswift" hypersonic-aircraft programme open to all (US) comers, and confirmed outline details of how the new unmanned hyperplane prototype will work.

In a government pdf released last week, DARPA says that Blackswift will indeed, as speculation had it, be reusable and make takeoffs and landings from an ordinary runway. The hyperplane will be required to reach Mach 6 - well in excess of the best speeds yet reached by runway aircraft - and maintain that stably for at least a minute.