] Randy Voland, project engineer at the Langley Research
] Center in Hampton, Va., another NASA site, said
] preliminary data indicated the X-43A was traveling at
] Mach 9.7, or 9.7 times the speed of sound, when it
] separated from its booster rocket at 111,000 feet about
] 90 seconds after launch. At that point, he said, the
] plane sustained its speed at Mach 9.6, or about 6,600
] miles an hour, during its 10-second engine burn.
]
] "It looked really, really good," Mr. Voland said of the
] flight. "In fact, it looked like one of our simulations."

The New York Times : Science : NASA Jet Sets Record for Speed