The Gaia focal plane

The astronomic mission Gaia is a cornerstone mission of the European Space Agency, due for launch in the 2011 time frame. Requiring extremely demanding performance, Gaia calls for the development of an unprecedented large focal plane featuring innovative technologies. For securing the very challenging Gaia Focal Plane Assembly (FPA) development, technology activities have been led by EADS Astrium from 2002 to 2005. After EADS Astrium selection for the development of the Gaia satellite, the program started in early 2006. The all-Silicon Carbide FPA hosts all the mission scientific functions for Astronometry, Photometry and Radial Velocity Spectrometry, encompassing 106 large scientific CCDs operated in TDI mode with windowing readout. With a sensitive area of about half a square meter, the FPA includes more than 935 millions of 10 μm x 30 μm pixels. To fulfill all the requirements, the CCDs feature a specific design with a Silicon Carbide package and on-chip functions such as TDI dynamic gain control and pulsed charge injection. Main development issues are related to the mass production of CCDs, and extremely low noise and miniaturized focal plane electronics. Finally, the major challenge of the overall focal plane mechanical and thermal accommodation is to allow full modularity while providing perfectly stable temperature and efficient thermal decoupling between the CCDs area (160 K - 170 K) and electronics operated in standard temperature conditions.