x-15 about to launch

 

The X-15, attached to its B-52 mother ship, with a T-38 flying nearby, reached its highest speed on October 3, 1967, when William J. Knight piloted it to a staggering 4,520 miles per hour (7,274 km/h; 2,021 m/s). Achieving Mach 6.7 at an altitude of 102,100 feet (31,120 m) or 19.34 miles, the X-15 set the official world record for the highest speed ever recorded by a crewed, powered aircraft. Remarkably, this record remains unbroken to this day, solidifying the X-15's place in aviation history as a true pioneer of high-speed flight.