Visionary schemes for weather and climate control have a long history, but with very few exceptions have ever worked. Would-be climate engineers and policymakers need to take this into account. The chapter explores by addressing a claim that although historical cases of weather modification provide a valuable context for thinking about climatic interventions, they represent different temporal and spatial scales, and therefore may be of limited comparative value. The Argus and Starfish Prime nuclear detonations in space, along with similar Soviet testing, constituted actual attempts to engineer space weather and disrupt the magnetosphere. History teaches us that things change–often in surprising or unanticipated ways–and that a certain amount of clarity can be gained by looking backward as we inevitably rush forward. Schemes aimed at attempted control of weather and climate–often framed as responses to critical problems such as water shortages, military exigencies, and cold war dominance–have fallen short of their goals many times.