Magnetic satellite missions: where have we been and where are we going?

High-quality magnetic observations have been obtained in recent years from a number of satellite missions. I discuss here the issues regarding the multi-year low-orbit satellite missions: طrsted, CHAMP and SAC-C, and briefly what is expected from the European Space Agencyʹs forthcoming Swarm constellation. The magnetic satellite data, combined with ground-based data, have provided unique opportunities for studying the core magnetic field and its secular variation, core flow, mantle conductivity and lithospheric composition, as well as the dynamics of the ionospheric and magnetospheric currents. A few examples of recent improvements in our knowledge of the magnetic field are presented, together with future investigations in measuring and modelling the Earthʹs magnetic field. To cite this article: M. Mandea, C. R. Geoscience 338 (2006).