If anyone is still working on new space maps, I've designed a few new terrains, covering all the planets in the Solar System, asteroids and Kuiper Belt Objects, interstellar space, various Milky Way objects, and a few things beyond. They are planned for inclusion in the next version of the space colonization modmod (with likely edits as needed). Please pardon their rough-and-ready appearance. You'll need SVN 9236+ to use them. Then just drop the folder in caveman2cosmos/Assets/Modules/My_Mods. I'd love to see a good map that stretches to the cosmos. I'll design one myself if I have to, but then it won't be good.