In the portion when you`re about to land on planet Gellix to rescue the defected CERBERUS scientists, right AFTER the scene where you speak to Jacob about things and right BEFORE you speak to Dr. Brynn, there is one ex-cerberus official (Dr. Brown) mourning to her husband right beside the screen (you can`t miss it), talk to her and you`ll automatically receive a +2 reputation. Afterwards pause the game and then save your data. Load it once again and you will notice that you`ll be in the same moment before you saved, and Dr. Brown is in the exact same position. Talk to her again and gain another +2 reputation. Do this as much as you want until you fill your reputation meter.