Project created for my engineer's thesis. Inspired by movies from International Space Station (espacially Col. Chris Hadfield movies/experiments). 
My ISS is based on model developed by NASA, but their has over 700k polys (over 1 milion vertices) and was not uniform (floating elements etc.). So my work started from modeling ISS from beginning to end and at the end I've reached 200k polys and 300k verices without sparing :).
Some parts of station are represented simpler than they are in reality (real-time rendering condition)
Station model was devided into several pieces because of vertices limit in UDK import module. So 17 parts of ISS model have been put together in scene. Whole station have been rotated and with random space dust particles floating around we have feeling of motion. Also sun cels have been rotated for more sun-oriented position. Simple materials. Only sun cells were mapped and have own texture with normal and specular maps. 
 
Skybox is simple cubemap with Sun which follows the DominantDirectionalLight direction so it looks very natural. Also lens flare with dust and debris for cool effect :).
Skybox material nodes.
Result of Skybox material.
Earth were supposed to be very simple object, maybe even plane with texture. In time and tutorials, the idea has grown. 
Atmosphere material nodes.
Earth material nodes.
Result.
Moon is some kind of filler (have Earth, why not to create the Moon?) :). Basic material + sphere. Simple and nice.
Moon material nodes.
The moon.
Day/Night transition.
Ofc added Post Proces Chain and  particles and lens flare. There is background sound such as radio connection and breathing in space suit for better 'feeling'.  Also text help for users have been created and little protection from getting too far from ISS :). 
View form UDK. 
I would like to thank everyone who contributed to the creation of this project, for motivation to start creating it and good advices to finish it :). 

You can download .exe from here: https://drive.google.com/file/d/0Bwg9GWr-lEROSnVYWWprajlDNkE/edit?usp=sharing

If You like it, please share Your opinion below  :)
Thanks for watching! :)