In the episode "Civilization", close to the episode finale we can see an underground mining facility. It is shown in a very quick cameo, yet I am pretty sure that it is large enough to be operated by a lot of people. I think I can even see some of them walking through corridors seen in that cameo.
Yet in one of the episode's final scenes Captain Archer says:
that there are only three aliens to beam aboard the alien vessel.
Was the mining facility fully automated and there was actually no one seen in the cameo?