This paper is a summary of a presentation done during the ELSA conference in Sèvres, on
June 7th 2010 to describe the actions of the French space agency for space astronomy.
It starts by remembering what was done for Hipparcos, then on more recent astronomy
programs. It describes the supporting role of CNES for the French astronomy laboratories,
and the acting role in the DPAC consortium for the Gaia data processing: CNES is
integrating the scientific chains of object processing (CU4), spectroscopic processing
(CU6) and astrophysical parameters (CU8) in one processing centre. It will be operated in
CNES during the whole Gaia mission.