Exit the tram and listen to the message. Open a couple of panels and grab a Small Med Pack from the waiting room. Proceed through the door. Walk the corridor and grab some ammo. In front of you is a store. After completing business there, turn left and enter the Main Atrium.
Explore the room. Near the right wall, there are two crates and an audio log; in the further left corner, you can find some Ripper ammo; more crates and Line Racks can be found further along the left wall. After collecting everything, take the ladder down behind the USG Ishimura symbol. There is a Save Station; proceed down and use the cargo lift.
Grab a Level 3 Suit Schematic and proceed through the door. After listening to Hammond and grabbing some stuff from panels and crate, head back. Upon reaching the Main Atrium again, move forward.
TIP: to kill the beast, listen to Hammond's advice - shoot it in the back! There is a yellow bulb that is a weak spot for the monster. Also, its arms can be shot off by hitting the weak spot near the shoulders. Using stasis helps a lot.
After the fight, proceed through the door the monster tore apart. Enter the Storage room, smash a crate and open some panels. There is also an upgrade bench here. Activate the elevator control. Now exit the room, come back to the Main Atrium and use the elevator to Ship Systems Level. Grab a video log.
Exit the elevator. There is a panel to your left; the room also contains two crates. Proceed forward. Another Save Station for you. Take the Contact Beam Schematic and continue walking. The small room in front of you contains two panels, a crate and Stasis Recharge. Exit the room and move to the right. Enter the door to Ship Systems.
Grab some ammo. Continue onwards, be careful and avoid stepping on the emanations coming out of floor. At the end of the small maze is a Stasis Recharge. Move the barrier out of the way and proceed further. To the left are some Ripper blades. Walk forward, slow the rampaging pipes with kinesis and activate the Power System console. Now proceed all the way back to the Main Atrium.
Enter the elevator on the opposite side of the elevator block (see the picture). Go down to level 1. Two crates and a Save Station await you. Enter the door. Another vacuum area! The small room labeled "MA Hall Storage" contains two panels and an upgrade bench and also allows you to take some breath of air and reset the oxygen counter.