This mission is fairly easy with good strategy.
I first started by mining all the outside resources that were safe for my bullpups to reach (not many enemies) but once you start mining a lot, then you go farther out where enemy troops "patrol" the area. So I build up a few fleets.
1 fleet of half security and half vehicles and go to the right and destroy the patrolling troops.
Another fleet (same as above) and go due south and stand guard in that area.
Then I build a HUGE fleet which i break into small groups to continue to barrage the base which is south east.
Getting into the base is rather difficult due to the fact that there are many forces guarding it and a lot of towers. I start by destroying the towers until the forces come upon me, then i take care of them then continue on the towers. I destroy the two towers in the south west entrance of the base and then immediately enter and destroy the power plants. After destroying the power plants i destroy the HRC and VTS. Then i just go from there
Also, the above usually takes most of my fleet to do, around 5 attacks.