G'Day,

there are several victory conditions including control of Metacol Rex.

Do you treat this as control of the planet only (and maybe enemy ships in orbit) or the system?

(There is at least one victory condition there no friendly ships are mentioned/needed to be fulfilled)

From the FAQ:

Q: For objectives that state “I control Mecatol Rex,” does this refer to the planet or the system?
A: The planet.