Contrary to some reports, Reiffel told CNN, the device would not have "blown up" the moon. "Absolutely not. It would have been microscopic, so to speak. It would have been, I think, essentially invisible from the Earth, even with a good telescope."

Reiffel had some brilliant minds on his team. One of them was an up-and-coming graduate student named Carl Sagan. Sagan went on to become one of the world's most renowned astronomers, creating the book and popular TV series "Cosmos."

But after working on the moon program, Reiffel said, Sagan violated security when he mentioned the still-classified project on a job application. "He did formally break the classification status of the project", Reiffel said of Sagan, who subsequently died in 1996.