Well, while everyone at NASA has been knocking their heads together trying to build a fully reuseable replacement for the Space Shuttle, it turns out the USAF and the CIA already had one.
Link: http://www.aviationnow.com/avnow/news/channel_awst_story.jsp?id=news/030606p1.xml
It's a nifty concept (and I love the idea of building a custom XB-70 as a carrier aircraft), but I doubt this revelation will have much affect on the civilian space arena. From the sounds of things it was a very specialized Black Project designed for recon missions, where cost was no object. Translating it into a civilian carrier that can compete economically with disposable launchers may or may not be a viable option, though I'm sure Rutan and Virgin Galactic will be hunting up for information that might useful for SpaceShip 2.
Link: http://www.aviationnow.com/avnow/news/channel_awst_story.jsp?id=news/030606p1.xml
It's a nifty concept (and I love the idea of building a custom XB-70 as a carrier aircraft), but I doubt this revelation will have much affect on the civilian space arena. From the sounds of things it was a very specialized Black Project designed for recon missions, where cost was no object. Translating it into a civilian carrier that can compete economically with disposable launchers may or may not be a viable option, though I'm sure Rutan and Virgin Galactic will be hunting up for information that might useful for SpaceShip 2.