During the Cold War, the XB-70 was designed to drop nuclear bombs on Russia: The North American XB-70 Valkyrie looked like it was plucked from the pages of a science fiction comic book in the late 1950s. The XB-70 will be the world's largest, fastest, and highest-flying bomber in history, with its sharp, angled design, six afterburning engines, and the most advanced targeting, navigation, and electronic warfare capabilities America can deploy.