An account by Brian O'Leary (1940-2011), an astronomer selected in 1967 for NASA's sixth astronaut group (the second intake of scientist-astronauts) who resigned eight months later. He recounts from the inside his application, the selection tests, settling in Houston and training, and paints a satire of the agency's internal culture: bureaucracy, the public-relations machine, and the dominance of test pilots over men of science. He sets out the unease that drove him out (the sidelining of scientists) puts forward proposals for reform and voices concern about the militarisation of the program, before closing on the future of planetary exploration. French edition of The Making of an Ex-Astronaut (1970).