Gaia focal plane assembly (engineering model)
This photograph shows the Gaia focal plane assembly (FPA) engineering model (EM) being prepared for testing in the vacuum chamber at Astrium, Toulouse, France.
In October 2010, the FPA EM underwent a series of electrical and functional tests that demonstrated that it is functionally fit for flight.
For these tests the FPA EM was fitted with two rows of 16 CCDs; the flight model will have 7 CCD rows and a total of 106 CCDs. The orange pads seen on several of the CCDs on the top row are small heaters that were used for the thermal testing. The wave front sensor (WFS) can be seen protruding from the row of CCDs.