Codenamed "Starfish Prime," the military formulated this operation just days after the discovery of the Van Allen radiation belts, which surround Earth. The plan was to send up several missiles in order to glean whether "a) If a bomb's radiation would make it harder to see what was up there (like incoming Russian missiles!); b) If an explosion would do any damage to objects nearby; c) If the Van Allen belts would move a blast down the bands to an earthly target (Moscow! for example); and — most peculiar — d) if a man-made explosion might "alter" the natural shape of the belts."
One hopes that this kind of testing never occurs again.