The article "North American XB-70 Valkyrie — America’s Cold War Supersonic Speed Bomber" by Friedrich Seiltgen, published on The Armory Life, discusses the history and development of the North American Aviation XB-70 Valkyrie, a planned supersonic strategic bomber for the United States Air Force. Intended to replace the Boeing B-52 Stratofortress and the Convair B-58 Hustler, the Valkyrie was designed during the Cold War to fly faster and higher, evading interceptor aircraft. The program, initiated in the mid-1950s, was ultimately canceled in 1961 due to advancements in Soviet surface-to-air missile technology and the rise of cost-effective Intercontinental Ballistic Missiles (ICBMs). The article highlights the Valkyrie's ambitious design goals, including a proposed cruising speed of Mach 3 and an operational altitude of 70,000-75,000 feet. Despite the cancellation, two prototypes were built, contributing valuable data on supersonic flight, aerodynamics, and airplane propulsion. The Valkyrie program also faced a tragic incident in 1966 involving a collision with an F-104 Starfighter during a photo shoot, leading to the destruction of one prototype. The surviving XB-70 is now displayed at the National Museum of the United States Air Force.