Histories of the Cold War have connected America’s first spy satellites to the increasing inability of the United States to monitor the Soviet ballistic missile program during the late-1950s. The technology of reconnaissance satellites, though, predates both the rockets necessary to loft them into orbit and the missiles the satellites later detected. Advocates of spy satellites never viewed the technology simply as a solution to any single “intelligence gap,” but as a novel intelligence resource that would do what no previous technology could: photograph whole nations during peacetime. Intended only as an “interim” technology until better platforms were invented, the first film-return spy satellites became a permanent fixture of national defense and helped define the parameters of the Nuclear Age.