What You Need to Know: The North American XB-70 Valkyrie epitomized Cold War aerospace innovation. Designed to replace the B-52, the Valkyrie boasted speeds exceeding Mach 3 and an altitude ...

A unique bomber-style fighter jet, the North American XB-70 Valkyrie has a top speed of around 2,050 mph, which is about Mach 3, depending on the altitude. This experimental fighter never ...

As a result, just as North American was starting to build the aircraft, the goal of the program shifted to high-speed flight research. The first XB-70 — nicknamed Valkyrie following a naming ...