The GAIA satellite will observe a large number of solar system objects, mainly asteroids, and although most of them shall be already known in the next decade, it will possibly discover new ones. The major scientific outcomes of this mission for the science of the Solar System is the survey of the inner-Earth orbits region, the determination of asteroids' physical parameters (masses, sizes, taxonomy...) for a large number of objects, detection of binary asteroids, accurate orbits determination, and tests of general relativity. Here we discuss the preparative work that should be done before launch regarding the scientific case, the software or instruments requirements, the catalogues output, and complementary ground-based observations.