My opinion/Computer controled: The toughest ship in the game; the alien fighter is faster than a bullet and recharges its shields at an astounding rate. The alien fighter uses the fly by technique while weilding its rather weak fusion beam at you. Destroying this ship is very hard (and also unecessary, which I'll get into later). You must have a Kestrel with maxed out guns/turrets and all three engine upgrades. Get your ship to hover above the fighters and unload your primary weapons. Do not use torpedos, missles, or rockets; they will knock the light ship out from under you. Once on top of the alien fighter rotate around him so he can't line you up with his fusion beam. After 15 minutes of this you should be okay. If you at any time get away from the fighter, you'll have to start over. It recovers 5% of is 500 shields a second. But this whole ordeal isn't necessary. On the alien mission you need only destroy the cruiser, nothing else.