Maintenance Level

The maintenance level and the connected waste disposal are locations onboard Mothership Zeta

Maintenance level
If the Lone Wanderer uses the teleportation matrix, next to the door to robot assembly, to the maintenance level during Among the Stars, they will find Sally attempting to fix the control panel on a Zeta trash can. She explains that she is not really lost and they 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 small hatch to the player character's right (when facing Sally) opening for them to look and shoot out:
 * A level with a single alien shooting at the player character.
 * A level containing brahmin. ("We're having burgers tonight!") and also ("Cows? We got cows!")... perhaps a reference to a line from "Twister."
 * A level with a Corvega in pristine condition.
 * A level with three aliens which the player character needs to clear out before Sally climbs their way "to try something out" (if one takes too long she will stay where she is and do that anyway).

The elevator will stop on the last level and involve a shoot-out with the three 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 character will show them scrabbling for grip inside the compactor, ultimately failing, and landing in a detritus ridden area with a newly crippled leg.

Sally then re-appears, and one can tell her they wish to go back the way they came but she will explain that is impossible unless the player character is "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."

Waste disposal
Inside, the player character will find a maze of trash compactors. One situated ahead, can be turned on and off and one will find it proves quite adept at destroying anything the player character places 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, ammunition and chems, and a first aid box.

Another maze of tubes and trash in the next room and Sally's voice emanates. In here there is a first aid box and a safe. If the player character did not heal themselves of the cripple earlier, there is a healing archway in this tunnel. Exit the door to find a support drone clearing garbage.

Above the drone, there are two aliens on the roof who will ambush the Lone Wanderer from their back when they enter a U-shaped walkway in the outer room. After defeating them, the player character can also find a military footlocker, which contains the unique item General Chase's overcoat, at a corner near the beginning of the walkway (map location A). At the end of the walkway, there is a door. When the player character passes it, two aliens will run from the tunnel (where the healing archway is), one of whom wields an inertia suppression field.

The player character will eventually come to a room with a guardian drone. They can destroy it for its drone cannon or push it onto the trash compactor. Either way, Sally opens the next doorway for them. If one turns off the compactor and proceeds, the door behind the player character will be sealed and thus there is no turning back.

The next room will contain 2-3 aliens who drop down from a rampway above. After, Sally will have opened doorway 2.

The next few rooms will be closed off similarly (all of these upper areas can be accessed by stacking the small boxes beside a doorway to make a set of stairs and leaping from the top of the doorway arch before sliding off the other side). The player character must wait a few seconds, possibly dispatching the aliens if spotted. Once through, Sally reports the radio has gone quiet, and they are ambushed in the next room. Grab alien captive recorded log 19 in here and kill all aliens until the doorway opens. There are also containers in this room.

Once through, travel through the next area and meet Sally. She tells the player character to check out the storage closet which contains a samurai's sword (map location B) and loads of first aid boxes. She then tells them to return to the core and '..never speak of this again.'

Loot

 * In the vicinity of the first aliens encountered in waste disposal, in a high-ceiling 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.
 * Alien captive recorded log #19 is in the room past the hallway of trash compactors, in the room where Sally says "ambush", just before the LAST room with the teleporter.
 * At the end of waste disposal, in the room where Sally meets the player character and wants to race them to the teleporter - opposite the getting into that room, in a closet type area with lots of medical kits, on the shelf in front of the player character is the samurai's sword. However, if Toshiro Kago has already made his disappearance, the sword will be gone from the shelf.

Appearances
Maintenance level and waste disposal appear only in the Fallout 3 add-on Mothership Zeta.

Behind the scenes

 * One of the Lone Wanderer's choices to begin the conversation with Sally before they enter waste disposal is "What an incredible smell you've discovered..." This is a reference to Star Wars IV: A New Hope when Han Solo follows Princess Leia, Luke and Chewbacca down a garbage chute into a magnetically-shielded trash compactor.
 * When the player character reaches the level with the brahmin and Sally says "Cows? We got cows!", this is a reference to the movie Twister in which one of the main characters says a similar line when a tornado starts hurling a cow across a road in front of their car.
 * When Sally asks the player character if they're alright after falling from the trash compactor to the floor, one of the dialogue choices is "Fine, fine, no thanks to you." This is a reference to the movie Spaceballs when Commanderette Zircon asks President Skroob if he is alright after being beamed back to his office, and Skroob indignantly responds to Zircon with that line.

Bugs

 * When loading from the autosave at the entrance to the maintenance level, it is possible that the game will not allow the player character to enter the elevator, and will push them away from the doorway when they step into it. The solution to this glitch is to go back through the teleporter into the engineering core, and then re-enter the maintenance level.
 * The teleport required to leave this section will be activated but not work, leaving the player character trapped.
 * Saving the game, restarting the console, and reloading in front of the teleport should allow the player character to proceed as normal.
 * A quick solution is to open the console and click on the teleporter and then type "activate" which will bring the player character to the destination.
 * Sometimes, nothing will happen when attempting to use the teleportation matrix in the engineering core to access the maintenance level. Reloading a save does not seem to fix the issue, although restarting the game did.