It is an accurate version of the nostromo, in space.
For LV-426, the map contain the colony (hadley's hope) the atmosphere processor, the derelict and landscape with caverns and many stuff like this. It's huge.
About Fury 161, it's indoor and outdoor location, accurate to the movie too.
Auriga is the ship interrior with all the location like the hanger where is the betty, the clone department, alien cages, etc.
It's huge too.
I'm firstly finishing Hadley's hope and LV-426 then I'll attack the other map.
I'll probably release a pre-beta version of Hadley to give you a 'taste' about what you can expect.
There'll be also a SP campaign based on the four movie using all the maps.