Delivered at the Palais de la Découverte on 19 February 1966, Albert Ducrocq surveys the multiple benefits of the space age for civilization. In three parts, he examines the scientific discoveries enabled by satellites (geology, meteorology, astronomy), the industrial potential of the space era (new materials, quality standards, plasma physics), and the contributions of space exploration to human biology, medicine, and global communication. The lecture ends with a humanist vision of humanity united through the planetary sharing of information.