David Sington's documentary about the US space programme sold to THINKFilm for North America during Sundance, where it won the world documentary audience award.
The film, originally commissioned by Channel4's Hamish Mykura and Louisa Bolch, and produced by Duncan Copp at Dox Productions in association with John Battsek's Passion Pictures.
Channel 4 said other buyers were circling the project.
The Madman deal was brokered by Channel 4 International's Nada Cirjanic, who is selling all rights worldwide excluding North America. Discovery Channel holds the TV rights for North America only.