A starbase is capable of performing either a Fix or a Recycle each turn. It can not perform both functions in the same turn.
After a starship has taken damage, you can use a starbase at the same location to repair the ship. The Fix command will repair all the damage done to the starship in one game turn. It will also bring the starship's crew complement to the normal number of crew members and bring the shields to full charge.
There is no Cancel button for this function. Since this command has no apparent negative effect, it is not necessary to cancel the action.
The starbase can also recycle old starships. When a starship is recycled using the Recycle command, the following actions are performed on it:
The recycling player will gain one PBP/PP.
There is no Cancel button for this function. It is instead necessary to select a different function or target. Since Fix has no apparent negative effect, it is common to cancel a Recycle by simply switching to Fix.