It is quite a trick to develop a carrier craft of that proportions (valkyrie size and performance) and an orbital spaceplane launching from an aircraft completely secret. That's a technology that has never been done before. Now if it would be sub-orbital, that's something different.
I'm not saying it ain't possible. But it's amazing there are no pics of it, while in my impression other supersecret projects did leak in form of "caught on tape/CCD
". I would suspect that the carrier craft in fact
is a modified Valkyrie. That would reduce the amount of test flights enormously, decreasing chances of being "caught" a lot. That would be amazing news as well, the Valkyrie finally being used beyond research flights
. They would have had to build a new one or complete airframe 3 though, otherwise a certain museum would notice something missing in the collection (btw they recently acquired a B2, that museum is totally over the top)
. As for the space plane itself: the Russians had official aircraft launched orbital craft plans, I'm sure the US had as well. The plans seemed quite realistic. And the russian plans were even based on a subsonic Mryia launch.
But still, to do it all secretly...it would be truly amazing if the spacecraft was truly orbital. Suborbital would still be nice an easier to explain how it was kept secret.