[Wardad]

Originally posted by Dobian:
Several of my asteroid fields are now exhausted of minerals...

Depletion of minerals by remote mining is figured in the simplest way possible. It depelets at one rate per turn no matter how much minerals your pulling from it. A SAT maybe cheaper, but your wasting a lot of potential resources from that field.
So the more experienced players prefer a large base with many of one type of miner. When the field is depleted of Minerals then the base can be refitted for RADs or Organics.
Remember the Base gets a maintenance reduction and a ship doesn't. A ship may cost more in maintenance than it can mine.
One more thing.... With the right tech a planet can be created from an asteroid field. The planet will have the fields resource Ratings. So think twice before remote mining.