Vers la conquête des mondes is the French translation of Willy Ley's landmark work Rockets, Missiles and Space Travel (Viking Press, 1951), one of the most significant works of popular science in the pre-Sputnik era. Structured in six chapters, the book traces the history of astronautics from ancient dreams of space travel to postwar rocketry, covering pioneers Goddard, Valier, and Oberth, the Berlin Raketenflugplatz experiments, and the V-2 programme at Peenemünde. Ley, co-founder of the VfR in 1927 and a first-hand witness to the birth of German rocketry, combines rigorous historical narrative with forward-looking vision: the final two chapters project the reader toward future spacecraft and interplanetary navigation. The French edition, published by Amiot-Dumont in the Bibliothèque de l'Aviation series, includes supplementary notes by Wernher von Braun.