Testing General Relativity with Atomic Clocks

Contribution for "The Nature of Gravity" (eds. F. Everitt et al)International audienceWe discuss perspectives for new tests of general relativity which are based on recent technological developments as well as new ideas. We focus our attention on tests performed with atomic clocks and do not repeat arguments present in the other contributions to the present volume. In particular, we present the scientific motivations of the space projects ACES and SAGAS