One thing that needs to be said to all GMs out there that haven't read every 40k book, and might only know the material from Dawn of War ect.. Do not get disheartened by those that have. They obviously do not get the big picture. The fact is there is countless solar systems not to mention the whole concept of the "Warp". So if you put something in your game and they think "but that doesn't exsist in 40k blah blah, and quotes some book by one of the dozen authors of 40k material." Guess what It Does Now. You can not tell me that in the year 41,000+ something somewhere Can Not exist. Here on earth we went from charriots to space travel in a fraction of that . Now granted the 40k atmosphere is what draws people in, but don't let it limit your creativity. You don't like something change it and move on, players don't like it have them GM and you play. Just some advice to those that I notice on the forums that have alot of questions and not many answers, make the answers and stick to them and it will work out.