This lecture explores the natural history of cold-war technologies. The machines of the Cold War were developed in dialogue with conceptions of “hostile” nature — punishing natural environments, turbulent natural phenomena, violent natural effects. Knowing these hostile natures, however, required new practices for representing them and for imagining their relationship to the machines of the Cold War. This talk focuses on the attempts of Canadian cold-war scientists to make “sporadic" atmospheric phenomena knowable, and to transform these potentially hostile effects into elements of a stable infrastructure for Cold War communications. Tracking those efforts through scientific images, experimental satellites, clandestine maps, and machine architectures, the talk argues that the history of survivable communications during the Cold War is, in part, a natural history: a history of the hostile and turbulent natural orders that developed in conversation with fallible machines.