How did you unlock galaxy 5?
i am stuck at para ark's power restore point
You have to fix para-ark just follow the quest line which will require you to go through galaxy 4 to get the fusion core from the storage bay. Once you beat Maci you should instantly get it the item you need you can choose to fight her right away or wait till she gets back on her ship, then just follow the rest of the quest line once you fix para-ark you should be able to get to reach galaxy 5 through the warp gate.