NEAT: an astrometric mission to detect nearby planetary systems down to the Earth mass

The NEAT (Nearby Earth Astrometric Telescope) mission is a proposition for an ESA space M-size mission within the Cosmic Vision 2015-2025 plan. The main scientific goal of the NEAT mission is to detect and characterize planetary systems in an exhaustive way down to one Earth mass in the habitable zone and further away, around nearby stars for F, G, and K spectral types. This survey would provide the actual planetary masses, the full characterization of the orbits including their inclination, for all the components of the planetary system down to that mass limit. NEAT will continue the work performed by Hipparcos and Gaia by reaching a precision that is improved by two orders of magnitude on pointed targets. We report in this paper the status of the work being carried out to technically validate NEAT.