Striking the Line
To end this three-parter, you realize some of the Shivans have actually hidden in low orbit of a gas giant. Your job is to confirm any hostile capital ship positions in the area, and call for support to take them down.
You're going to have to deal with two Cains and a Lilith, with a hefty fighter escort, but you're going to need some heavy firepower. Have whatever team mates you have to take on the fighters, then get within 200 meters of each Shivan capital ship.
After that, you need to destroy the Lilith's main beam cannon. Three Trebuchet missiles will do the trick.
Then a Hectate-class destroyer will come in and destroy all three Shivan capital ships. Clean out any fighters and get out. A Ravana-class destroyer will show up 20 kilometers away, and don't think of fighting it, so leave when you get the order.