ROB is a federal research institute working under the aegis of the Belgian Federal Science Policy (BELSPO). The Operational Directorate of “Reference Systems and Planetology”, has specialized in research in planetary sciences and in particular in geophysics. It has expertise in radio science and gravimetric measurements in particular. Modelling efforts are focused on orbits,, planetary rotation, deformation, gravity, interior structure and evolution. ROB is involved in current planetary missions of European Space Agency (ExoMars, JUICE) and actively contributes to the development of new missions (HERA, DART, ENVISION, MMX) with the objective of studying the subsurface and interior structure.