Ok. I need to get to the tomb area to talk to the alien for the last time with Maggie. Trouble is the light bridge wasn't activated and the tram doesn't work to the tomb area. I tried re adjusting the blue crystals in the airlock room, but nothing.

Any ideas?

That's quite odd. I honestly don't remember that specifically about it, but by the time you discover the alien aren't all the light bridges supposed to be turned on? And if the tram isn't working either that's because the power isn't on.

I can't think of a real solution other than picking up from a prior saved game, or just start over.