Story related and you can't miss it. While you are in Atlantic express you will come across a splicer that runs away from you and a door shuts behind him. You need to go into the room the right and pick up the Hack Tool and use it on the control panel thats on the other side of the door. Shoot a remote hack dart through the broken window at the control panel and when the hack game comes up, hit E when the arrow is in the green or blue (may be more than 1 time) and the door will open.