The XB-70 Valkyrie was born from a simple Cold War idea: fly so high and fast that nothing could touch you. North American’s ...

The North American XB-70 Valkyrie embodied a once-dominant creed: outrun defenses at Mach 3 and 70,000 feet. -The prototype proved the physics—compression-lift wingtips, hot-structure skins, 172,000 ...