Why America’s Nuclear-Powered SLAM Missile Never Flew

In the late nineteen fifties, the United States began developing the most terrifying weapon ever conceived, a nuclear powered cruise missile that could fly at three times the speed of sound, at treetop level, for unlimited range, carrying multiple thermonuclear warheads to targets across the globe. Code named Project Pluto, the program produced a working nuclear ramjet engine called Tory, which was successfully tested at full power in the Nevada desert in nineteen sixty four. The missile it was designed to propel, the Supersonic Low Altitude Missile known as SLAM, would have been virtually unstoppable. Engineers at the Lawrence Radiation Laboratory in Livermore, California solved every technical challenge thrown at them, from building ceramic fuel elements with a beer company to finding exhaust paint in a hot rod magazine that worked where aerospace coatings failed. Yet despite the program's complete technical success, America chose to cancel the flying crowbar before it ever took flight. This documentary explores the full history of Project Pluto, from its origins in Cold War strategic planning through the remarkable engineering achievements at Jackass Flats, to the political and strategic reasons that killed the program, and the surprising echoes of the flying crowbar that persist in weapons development to this day.