In 1958, the United States Air Force proposed exploding a Hiroshima-size atom bomb on the surface of the Moon. Project A119, or “A Study of Lunar Research Flights” as it was also known, was headed by physicist Leonard Reiffel.
“People were worried very much by Gargarin and Sputnik and the very great accomplishments of the Soviet Union in those days, and in comparison, the United States was feared to be looking puny,” Reiffel told CNN. “So this was a concept to sort of reassure people that the United States could maintain a mutually-assured deterrence, and therefore avoid any huge conflagration on the Earth.”
The calculations were done by famed astronomer Carl Sagan. In fact, the project only came to light because Sagan listed the classified project on a job application.
Ultimately, the mission was scuttled due to growing concerns about contaminating the Moon, the weapon’s reliability, and possible backlash from the public.