I don't know what the requirements are for that mission (I've never once passed it), but I feel it's the worst mission in the game and impossible to do in a binary system. I can't really offer suggestions.. Maybe make it so that if the gates are farther than say.. 3 or 4 hundred light seconds then do a different mission.
I play freighter and that might be why I think the mission is impossible. The ares deliberately attack the smaller freighters and ignore your wingmen while also getting into point blank range so that your shots also hit the freighters.
I can't do the Terra mission because I can't get the rank needed and I'm afraid that if I decline this stupid mission any more times, I'll lose fleet credibility. I've jump drive before and after Pt. Juno because I want to do that mission too, but again - not enough rank.
TL;DR - I HATE THE REFUGE CONVOY

*edit: 2 systems later there was another CSC. Crisis averted. I'm a lieutenant now.