Simple, add additional columns for the frame of reference (e.g. Earth) and elevation. You could even store space coordinates using Sun as a reference point (though you would need to update data regularly for spacecraft as they move of course).

Why do you need to store the name of a country in the database? Frontend can take the country code and display a full name on its own, and do it in a localized way too.

AFAIK kernel itself doesn’t send any signals to processes on shutdown/reboot, it just stops executing them. This is a job service manager (e.g. systemd) that terminates processes using SIGTERM before asking kernel to shutdown.

That’s why you launch them through systemd.