XB-70 Valkyrie
North American Aviation constructed the XB-70 Valkyrie as a prototype for the B-70. The manufacturer’s goal was to operate at an altitude of 70,000 feet and hit a cruise speed of Mach 3. Essentially the aircraft could “ride” its shock wave. The XB-70 took its first flight in 1964. Around that time, Kennedy Administration canceled the project. Many saw a high-speed manned strategic bomber as unnecessary due to the capabilities of missiles. Though XB-70 was still active until 1969, Nasa wanted to use the aircraft to examine the “control of structural dynamics.”