Alright, just give me some time on this one because I am going to make this arcologic spacecraft well over 10,000,000,000 blocks big.  BTW those 10 zero's means ten BILLION.  No known picture of the spacecraft because it's going to be built completely out of creativity.  "One does not simply outbuild Elmo114."  I am trying my best to outbuild Elmo114.  So here I go!  If you want to see what the interior of the spacecraft looks like so far (just the interior.  Not building the outside yet) then download the world save file.  Oh and yes, IT'S OVER 9000 million blocks big!  I've only placed about 44 million blocks so far meaning the spacecraft is not even 1% complete!
Give me any ideas that I should add to this spacecraft in the comments below.  Thx.  :)