I just
ran across this on Wired.
I haven't heard of project Blackswift before, but they have an earlier
article
as well.

Defense officials are tight-lipped about details surrounding the Blackswift program. One source would only say its goal is to fly “higher and
faster” than the vehicle worked on during its predecessor project.
One of Blackswift’s key characteristics is that it will be capable of “powered and recoverable hypersonic flight,” which means the craft can
safely return to Earth and be reused, one official said. “That’s new for us,” the source added.
Anyone know more about this project?