X 43 A Goes 7, 000 MPH Getting Ready for Mach 10

X43A Raises the Bar to Mach 9. 6 Guinness World Records recognized NASA s X43A scramjet with a new world speed record for a jetpowered aircraft Mach 9. 6, or nearly 7, 000 mph. The X43A set the new mark and broke its own world record on its third and final flight on Nov. 16, 2004. In March 2004, the X43A set the previous record of Mach 6. 8 (nearly 5, 000 mph). The fastest airbreathing, manned vehicle, the U. S. Air Force SR71, achieved slightly more than Mach 3. 2. The X43A more than doubled, then tripled, the top speed of the jetpowered SR71. The X43 is an unmanned experimental hypersonic aircraft design with multiple planned scale variations meant to test different aspects of hypersonic flight. It is part of NASA s HyperX program. A winged booster rocket with the X43 itself at the tip, called a stack, is launched from a carrier plane. After the booster rocke br, br,