I went ahead and started Mothership Zeta without any problems until I got to the quest 'Among the Stars' in which I am unable to use the teleport and the doors are also locked. I didn't take Elliot with me as he said I've already went to work on the place so I don't need him, unable to gain his companionship for that part of the quest.

Have I now encountered a ground breaking bug in which I am now unable to continue with my game as I've got no other saves previous to this. (Being the idiot I am)

Help would be greatly appreciated, thanks!

I don't know if that's exactly your problem but I found this mentioned in Bugs section of that quest:

• Upon entering the room with the two soldiers in the Cryo Lab, the entrance doors may become locked and the teleporter is inoperative. This results in being stuck in this level. This only happens when the player activates the revival process before Elliott is ready thus resulting in the death of his squad mates. When this happens Elliott will have a speech option asking him why the doors have locked. If the player chooses this option Elliot tells the player that "we probably just have to wait for the decontamination cycle to end." despite the fact that no matter how long the player waits, the doors will not open. There are two solutions. Solution 1: save, then power down the console/exit the game on the PC. Load that save and the teleporter should be operational again. If this occurs on the PS3 version, restarting the console has no effect. Solution 2: Sadly, killing Elliott Tercorian does fix the problem. This results in no negative Karma. Killing the revived soldiers also fixes the problem.

This is exactly my problem, thank you!

I see no mention of the 360 solution so I'm going to assume the save, turn console off and reload will work on 360? It also said nothing about that solution not working for the 360 so I'll try this. Thank you again.

Yes, from what I understand, solution 1 refers to both 360 and PC. If nothing else works, there's still solution 2.