Determining the kinematics of the dwarf Spheroidal galaxies (dSph) satellites of the Milky Way (MW) is crucial to estimate the mass of our galaxy, to understand its formation process and that of its satellites, to explain the origin of stellar streams in the MW's halo that seem to be related to these satellites, and to understand the role of tidal interactions in the evolution and star formation history of low mass galaxies and of the halo of our Galaxy. In what follows we briefly explain a ground-based astrometric project that will have an impact on these issues, and present some preliminary results.