On the performance of the Gaia auto-collimating flat mirror assembly: could it be even better?

The Auto-collimating Flat Mirror Assembly (AFMA) simulated the rotation of the Gaia satellite around its vertical axis. As such, it was one of the most important ground support equipment tools to test the payload performance of the Gaia mission. Although the performance of TNO's design during commissioning was excellent, one of the challenges of the AFMA design and realisation has proven to be the prediction of the dynamic behaviour of AFMA and the accurate prediction of its performance. Therefore, the dynamic behaviour of Gaia AFMA has recently been re-analysed. Dynamical points of attention are shown, and possible design improvements have been derived.