I suddenly noticed that I can't find a spaceport option for any of my planets. I dunno when that disappeared, I'm pretty far into the game. I have Retribution and all the official DLCs on an asus intel-based laptop. Is there a game mechanic that could cause this to go away? If I can't build spaceports around newly conquered planets, I may not be able to continue this game which would suck. (I know the workaround is constructors, but they cost an administrative point.) 
Any thoughts? Thanks for any help you can provide!