♫ Galileo, Galileo... ♫
One man's mistake, missing backups and complete reboot: The tale of Europe’s Galileo satellites going dark • The Registerhttps://www.theregister.co.uk/2019/11/08/galileo_satellites_outage/
Like any complex system, Europe's Galileo satellite navigation system has multiple points of weakness. Starting with the fact that while it has 26 satellites in its constellation vs. 24 required to achieve its specified accuracy, only 21 of them currently actually work.
But as with any complex system, it's when multiple failure modes start stacking on top of each other that it all drops in the pot. And often — as in this case — many of the weaknesses in the system are human.
Also, we now know that it takes about three days to completely reboot the Galileo navigation system. Don't ask the EGSA how they know this. The question seems to make them cranky.