Operation Starfish Prime High Altitude Nuclear Test
Operation Starfish Prime mattered because it revealed that a nuclear weapon detonated high above the Earth could wound more than a target. It could reach into the electrical habits of a distant city, flood near-Earth space with artificial radiation, and damage satellites that had not even been imagined as battlefield casualties a few years earlier. What the United States wanted was data. What it got was a warning. In that form, Starfish Prime became more than a spectacular test. It became one of the clearest Cold War examples of a black program discovering that the sky itself could become a contaminated battlespace.