The hangar is the part of the ship where smaller spacecraft enter and exit Mothership Zeta. When you arrive, you can see a recon craft Theta enter through the hangar door in the floor. Within the hangar is one of the generators that must be destroyed as part of the Among the Stars quest. If you requested his help, Paulson will follow you into this area. Once you get to the control center and activate a button, an alarm will go off alerting the aliens to your presence. Thus begins a rather fun battle using the gravity beams that hold up recon craft Theta. The upper level of the hangar includes a console with five buttons; each button causes a pair of the beams to emit bursts of energy that send the aliens and their drones flying. This is both a fun and effective way to repel the waves of attackers; just be sure to place a few mines at the doors in case some aliens find their way to you.
After the battle, the previously blocked off rooms on the lower east side are open. The north eastern room has crystals and the south eastern room has 5 packs of alien power modules and an alien atomizer.
If you fall/jump down the hole that recon craft Theta comes through, you fall about halfway down, then sort of bounce up a bit whenever you fall farther. The fall does kill you. If any of the aliens fall into the pit, they will be killed automatically as well.
Due to the sheer number of enemies in one area, and the platform the game is built off of (Havok Physics), most of the bodies will have disappeared after the main battle. This makes it almost impossible to loot all of the bodies before they disappear. If you want more loot, let some enemies through to the room where you are and kill and loot them there.
One of the guardian drones in the room overlooking recon craft Theta may have their drone cannon equipped backwards, going through it and pointing out the back. It is still targetable, but at a reduced chance of a successful shot. Also, it is (somehow) able to attack targets in front of it, the drone cannon will flick down, but it will never face forward.
In the generator room at the end of the area, there is an inactive teleporter. If you look through this teleporter, you may actually get a 'Search alien' prompt and be able to loot this seemingly nonexistent body. If you turn on your Pip-Boy light, you will see gore of an alien body.
When you go through the door that takes you to the control room, sometimes you can't walk through the door, as if the shield was still there.
You can get stuck once you get past the door and will have to restart it.