In the years after Hiroshima and Nagasaki, a group of physicists set out to turn the bomb into a rocket engine. Project Orion's plan was blunt: eject small nuclear charges behind a spacecraft and ride the shockwaves, using a pusher plate and shock absorbers to survive blasts intense enough to loft a vessel the size of a building. Ted Taylor led the design work, and Freeman Dyson joined to run the physics, both convinced the concept could reach Mars, or even Saturn, within a human lifetime using 1950s materials science. The film traces the program from its classified beginnings through scale-model tests using conventional explosives, footage of which survives and appears here, to its collision with the 1963 Partial Test Ban Treaty, which outlawed the atmospheric detonations the whole design depended on. Interviews with surviving scientists and archival material lay out both the engineering logic and the political nerve it took to propose flying nuclear bombs into orbit.