I'll see what I can find on guides to helping voidcraft. I've never served on a mission craft but from what I understand a lot of helping a voidcraft comes from helping its crew. The higher morale of the crew is the better it is for the voidcraft. So until I can find you resources I guess my advice is make sure your crew are well looked after, deal with any problems before they blow up. I know that must be difficult when you gain and lose people so often.