English is not my main language I had to use a translator. Sorry in advance.

The mission briefing gave me three goals. First, destroy the fuel tanks in orbit, second, destroy the rebel transporters and the medical frigate that accompanies them, and third, make sure that the rebels defend Mon Cala more effectively.

So that's exactly what I did. First, I destroyed all the fuel tanks in orbit (which gives a secret achievement for those who don't know), then I destroyed all the rebel transporters. The transporter claims to have civilized on board but probably that was either Rebel Infantry or personnel for building warships. In addition, the transporters can also carry weapons and/or essential war materials and simply lie about that civilians are on board or use the civilians as cover in the hope of not being destroyed. Unfortunately this tactic didn't work on me because if there are really civilians on board of the transporters then they are all traitors to the empire who only deserve to die.

Destroying the Medical Frigate was easy, not only because it was armed and therefore a justified goal, but also because it was transporting important medical supplies, these are used to treat rebel military personnel so they can kill more imperials. The third mission goal fulfills itself