Warhammer 40,000: Rogue Trader

After you "save" Rykad Minoris, your parade is cut short by an attack and you have to evacuate to the Starport. Along the way you'll want to make sure you keep your traumas to as little as possible, so save and reload often, because right when you reach the Starport you'll enter into a dialogue between the military and the nobles. No matter what route you choose in the dialogue it's cut short when the boss destroys one of the shuttles and attacks you. Be sure to save as soon as you can, since you can save during fights, in case you don't manage to stop the boss. From what I've seen protecting the shuttles comes down to a bit of luck because during the second round the boss will 90% of the time ignore you and attack a shuttle, destroying it in one move. Hopefully your builds are strong because you'll need to focus entirely on the boss, ignore the 6 easier enemies. If you have melee focused characters like Abelard be sure to set them up so that you can possibly kill the boss with an opportunity attack if he starts walking towards the shuttle.

I managed to get this on my 3rd or 4th try but I also used builds I found on youtube so I knew how to use the skills and what the potential damage should be.

Defeat the Chaos Marine before he destroys even one shuttle.

Got this first try. With any Warrior, ideally tanky, you can use Taunting Scream to keep Boss- Aurora (Chaos Marine) focused on them as you quickly eliminate the 6 or so weaker mobs then focus all on him. Abelard is great for this role and he should be your main tank anyway at this point, Heinrix can do this as well. Also with Cassia, you can use Notch of Purpose to pull Aurora closer to your party near the point where you entered. Using these you should be able to keep him off any shuttle as game will priotize hurting your party over the shuttles. It helped having Pasqal, Idira, and Cassia debuffing, as my Psyker main character and Argenta did their damage.