Making the rounds: NASA successfully completed its Hyper-X program yesterday, with the successful Mach 10 flight of the last X-43A. It was mounted on a Pegasus rocket and then dropped from a B-52. When the rocket reached 110,000 feet, the X-43A craft separated and continued powered flight using its scramjet engine. This milestone represents a significant advance in propulsion technology, as previous scramjet flights had never made it past Mach 5.

For reference, escape velocity (required to get into Earth orbit) is around Mach 33 at sea level, and around mach 25 at very high altitude. I think. Air pressure and temperature are critical to this measurement, and math makes my head hurt.