The Ecole Normale Supérieure in Paris is offering two postdoctoral positions and one senior postdoctoral position within its newly established Space Chair, dedicated to exploring the Earth-Space relationship through the lens of human and social sciences. The Chair, launched in February 2024, is highly interdisciplinary and engages with scientific and technological developments in the space sector. Research activities are organized around three main axes: (1) the diversification of uses of outer space and the evolution of its representations, especially in light of new scientific discoveries and exploration missions; (2) conceptualizing space as a territory or common good for humanity, examining tensions between collective ambitions and commercial/state interests; and (3) investigating the contribution of space to planetary preservation and sustainable uses. The Chair is supported by a broad network of PSL University research communities, including CERES, CIENS, CIEE, the ENS Geosciences Department, the ENS Chair in Geopolitics of Risk, and the Observatoire de Paris. Candidates should hold a PhD (or expect to complete one by October 2025) in a relevant discipline such as economics, history, geopolitics, political science, philosophy, law, sociology, cybersecurity, geosciences, climate and environmental sciences, or astronomy. Prior experience in space-related research is not required, as the Chair encourages new perspectives on space as a research field. Successful applicants will demonstrate the ability to work in a multidisciplinary environment. The position is full-time, based in Paris at the ENS rue d'Ulm campus, with possible attachment to ENS laboratories or other PSL establishments. The contract is for one year, renewable for six months, with salary dependent on experience. For further information or to apply, contact Dr. Stephanie Ruphy, scientific director of the Chair, at stephanie.ruphy@ens.psl.eu. Applications are due by December 1, 2025.