I was thinking of some attack types that could be added and here is what I came up with:
Raid Mothership:
You have a raid asteroid base why not the mothership too?
It would have your fleets vs. enemy fleets then based on the amount of damage inflicted and sustained by you ships you would get segs and credits that they had on hand.
All out attack:
This could work like a regular attack except they keep going 'til either the attacker or defender has no more ships left.
Of course for this one the hp would continue to be damaged and the acu. penalty would have to be lowered going into multiple waves of attacks but I think it would be fun
Let me know what you guys think and add anything you might think will improve them.