Written for young readers, Les colonies de l'espace introduces the space-colonization project developed in the 1970s by Princeton physicist Gerard K. O'Neill: vast artificial habitats placed at the Lagrange points, powered by solar energy and built from materials mined on the Moon. Frederic Golden alternates a speculative narrative (daily life in a colony in 2030), a history of the dream of space travel (from Lucian of Samosata to Tsiolkovsky) and an account of the project's technical stages (orbital stations, lunar mining, Bernal spheres and Stanford tori). An epilogue added by Jean-Pierre Verdet for the French edition recounts the first flight of the Space Shuttle Columbia in April 1981. A glossary and an index complete the volume.