The SR-3 Blackstar was a two-stage-to-orbit system that used the XB-70 configuration for the mothership to carry an X-Orbiting Vehicle to over 124,000 ft for launching. The XOV rode on the back and then separated to fly on rocket power to any position over the earth for recon. The two planes would then return to different areas, the SR-3 under power while the XOV glided back to earth like the shuttle (as such it had air-brakes and heat tiles). The SR-3 was approx. 200 ft long and a delta span of 120 ft with bent tips. Speculation is that it ran on 4x hydrogen-fueled engines. Many believe that this is also known as the "Brilliant Buzzard" and/or "Super Valkyrie" spotted over Groom Lake, Nevada, California, Holloman AFB, and even the North Sea. Whether Aurora or not, it was seen by US F-15 drivers and British Tornado ADV drivers. It is rumored that it was shelved at Groom Lake in 2006. Perhaps ASTRA started operating from then on...???

http://digitalvideo.8m.net/blackstar/blackstar.jpg