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.
In July 2019, the Gaia mission entered its mission extension phase.
Gaia is currently in its second mission extension which runs until the end of 2022.
An indicative approval has been given for a third mission extension, which will run from 2023 to the end of 2025.
The observation predictions also cover the mission extension period.