Published twenty years after Sputnik, this essay traces the political, military and economic history of spaceflight rather than its technical adventure. Part one analyses the "cold war in the cosmos" from 1957 to 1969: Sputnik diplomacy, the secrecy of the Soviet programme, reconnaissance satellites and the race to the Moon. Part two examines spaceflight in the late 1970s: détente and the Apollo-Soyuz flight, the militarization of space, the Space Shuttle, the Soviet programme, commercial applications (telecommunications, remote sensing) and the rise of a European, Chinese and Japanese "third space." The author argues that the conquest of space expresses the political, military and economic power relations of its time.