Maintenance Level

The  and the connected Waste Disposal are locations on board Mothership Zeta.

Maintenance Level
If you use the Teleportation Matrix to the Maintenance Level during Among the Stars, you will find Sally attempting to fix the control panel on a Zeta trash can. She explains that she is not really lost and you both might find 'something neat'. Before long though, it starts moving, and it's a long way down...

The trash can stops at several levels of the Zeta Mothership:
 * A level with a single Alien.
 * A level containing Brahmin. ("We got cows!")
 * A level with a Corvega in pristine condition.
 * A level with 4-5 Aliens.

The elevator will stop on the last level and involve a shoot-out with aliens. Sally will then climb out of the compactor, explaining that she will figure something out to get it moving again. The trash compactor will then suddenly plummet. A first person view of the player will show you scrabbling for grip inside the compactor, ultimately failing, and landing in a detritus ridden area with a newly crippled leg.
 * If the player manages to stay hidden from the aliens for about 2 minutes (using Chinese Stealth Armor or Stealth Boys), the aliens will automatically die.

Sally then re-appears. You can tell her you wish to go back the way you came but she will explain that is impossible unless "you are Captain Cosmos". Sally runs off after deciding to split up, explaining that she will "try to find a way to get you out of there." Use a stimpak (or wait for a later healing archway) to heal your leg, then open the door to Waste Disposal.

Waste Disposal
Inside you will find a maze of trash compactors. One situated ahead, can be turned on and off and you will find it proves quite adept at destroying anything you place in its path. To the lower east of this room is a grid of trash compactors, examine the rhythm or run through to two safes (one Hard, one Very Easy) containing caps, ammo and chems, and a First Aid Box. Just watch where you walk, and head to the exit to this room in the lower west corner.

Another maze of tubes and trash in the next room and Sally's voice emanates. In here there is a First Aid box containing a Stimpak and Rad-X and a safe. Exit the door to find a Support Drone clearing garbage. If you didn't heal yourself of the cripple earlier, there is a healing archway in this tunnel. Go through the next room of trash, to find 2 aliens up on a walkway in the next room. Kill these, or stealth past and you will eventually come to a room with a Guardian Drone. You can kill it for its Drone Cannon or push it onto the trash compactor. Either way Sally opens the next doorway for you.

The next room will contain 2-3 aliens who drop down from a rampway above, unless you're adequately stealthed. Dispatch these somehow using the trash compactor, or just kill them, and Sally will have opened doorway 2.

The next few rooms will be closed off similarly. You must wait a few seconds, possibly dispatching the aliens if spotted. Once through, Sally reports the radio has gone quiet, and you are ambushed in the next room. Grab Alien Captive Recorded Log 19 in here and kill all Aliens till the doorway opens. There are also containers in this room. Once through, travel through the next area and meet Sally. She tells you to check out the storage closet which contains a Samurai's Sword and loads of First Aid Boxes. She then tells you to return to the core and '..never speak of this again.'

Notable loot

 * In the vicinity of the first aliens encountered in Waste Disposal, in a high-ceilinged room with a low metal catwalk, a Military Footlocker can be found on the floor to the right of the railing, against the east wall. It contains General Chase's Overcoat along with a blank holotape labeled Anchorage Quartermaster Shipment.
 * At the end of Waste Disposal, in a room with lots of medical kits, is Samurai's Sword.

Bugs

 * Sally will disappear from both the Engineering Core and the Maintenance Level
 * General Chase's Overcoat, when worn, appears as the Winterized Combat armor.
 * (Confirmed, Xbox 360) When loading from the autosave at the entrance to the Maintenance Level, it is possible that the game will not allow the player to enter the elevator, and will push the player away from the doorway when they step into it. The solution to this glitch is to go back trough the teleporter into the Engineering Core, and then re-enter the Maintenance Level.
 * Just before reuniting with Sally, the player may encounter an alien which dies before the player can attack it. The alien is holding two Alien Atomizers, one of which is in perfect condition. When the player attempts to equip this Atomizer, the message "You cannot equip this item." is displayed. If it is dropped and picked back up again, it can be equipped, but still does not stack with other Atomizers. (Unconfirmed Xbox 360)
 * After meeting with Sally near the end of the Waste Disposal area, there is a bridge over a pit with some garbage in it. The player is able to walk on air beside the bridge - probably because there is no way out of the pit if it were possible to fall into it.
 * Sometimes when lockpicking the safes in the Waste Disposal area, the lock & pick sound may be silent, forcing you to pick by eye, or exit the lockpick mode several times until you get sounds.
 * Sally might spawn and walk along the path you are required to take (and get hit by the trash compactors making her go flying across the room)
 * The trash compactors may cause a extremely violent death sequence that involves you turning into chunks and the camera following two of the chunks and some blood outside of the map and sometimes flying into the next room or further. (Confirmed Xbox 360)

Appearances
Maintenance Level and Waste Disposal appear in the Fallout 3 add-on Mothership Zeta.

Behind the scenes

 * One of your choices to begin the conversation with Sally before you enter Waste Disposal is "What an incredible smell you've discovered..." This is a reference to Star Wars: A New Hope when Han Solo follows Leia, Luke, and Chewbacca down a garbage chute into a magnetically-shielded trash compactor.
 * When you reach the level with the Brahmin and Sally says "Cows? We Got Cows!", this could be a reference to the movie Twister in which one of the main characters says a similar line when a tornado starts hurling cows across a road in front of their car.