Made prior to the disastrous accident that destroyed one of two prototypes, The XB70 Story describes the development and flight testing of the Valkyrie supersonic bomber. The North American Aviation XB70 Valkyrie was the prototype of the B70 nucleararmed, deeppenetration strategic bomber for the Strategic Air Command of the U.S. Air Force. In the 1950s, the North American Aviation company designed the Valkyrie bomber as a large, sixengine aircraft capable of reaching Mach 3+ while flying at 70,000 feet (21,000 m), which velocity and altitude capabilities would allow the evasion of interceptor aircraft, then the only effective weapon against bomber aircraft.

In 1961, improved, highaltitude surfacetoair missiles (SAMs), the U.S. Air Force's doctrinal change to lowlevel penetration bombing, the large development costs of the B70 program, and the introduction of intercontinental ballistic missiles (ICBMs) to the U.S. nuclear arsenal, led to the cancellation of the B70 program. As such, two prototype aircraft were built, and designated XB70A; these aircraft were used for supersonic testflights during 1964–69. In 1966, one prototype crashed after colliding in midair with a smaller jet aircraft; the remaining Valkyrie bomber is in the National Museum of the United States Air Force, in Ohio.