Gauntlet:
Instead of a planetary assault, your orders are to go to a planet already under assault. You have a number of items to transport down, and wounded to evacuate.
To assist you, you have a small screening force to engage the enemy fleet, but the enemy fleet to too powerful for you to neutralise. By the time you arrive at the planet, the enemy fleet is hot on your heels. You can win this mission without firing a shot, but if you try to slug it out, you WILL die.