On these missions, there is a target vehicle (which I refer to with the military parlance of "High Value Unit" (HVU)) with a bunch of escorts around it. The escorts are fairly average for enemies in the game, but the HVU has an insane number of hit points, up to 50,000,000 (50 million). On each sortie, you get 5 turns to fight through the escorts and do as much damage as possible to the HVU. Since most hits in the game only do a couple thousand damage, this is where it helps to buff your loading speed as much as possible.

The damage done to the HVU is cumulative between all the attacks upon it (from all the people in the coalition/guild/clan), although the escorts reappear every sortie. At the last levels you can barely scratch the thing on each attempt, but the higher the fraction of the total damage you contribute (up to 10%), the better the rewards.