This tool provides a forecast of times targets cross the Gaia Focal Plane.
It is based on the scanning operations of Gaia. It does not take into account operational activities preventing nominal observations nor matters like e.g.
the gaps between CCDs on the Focal Plane.
Adding up all dead time components, users should understand that the probability of the data of the target being received on the ground at the indicated time is about 80%.
Furthermore, only targets in magnitude range 6<G<20 mag are observed in astrometry and photometry and 6<G_RVS<16 mag in spectroscopy.
Please note that one more spin phase adjustment to the Gaia orbit will be implemented at a later stage.
Therefore the predicted observation time may deviate by up to 6 hours from the actual observation time.
The observation predictions do not cover the extended mission phase yet, i.e., this tool will only provide predictions until 2019-06-20.
The Gaia mission then enters its confirmed mission extension until the end of 2020.
Additional extensions to the mission are dependent upon decisions to be taken. An indicative extension has been given until the end of 2022 but is still waiting for its formal approval.