ELI5: Explain Like I'm 5

Project Pluto

Project Pluto is a project to build a nuclear-powered cruise missile. It was created during the Cold War, the time period when the United States and the Soviet Union were competing to build the best military weapons. The idea of Project Pluto was to make a missile that would fly much higher and faster than existing missiles, enabling it to fly long distances and reach its target more quickly. It also was meant to be powered by nuclear energy instead of using fuel, which would make it able to stay in the air for much longer and be able to cause more destruction when it finally reached its target. Unfortunately, the plans for Project Pluto were never carried out because it was too expensive and there were concerns about its environmental impacts.