I know that it isn't really all that important in the theories and general backstory of Zombies, but I have an idea on where the three rockets on Moon came from!
Rocket one:
I think this rocket came from Ascension, mostly because of the easter egg, and I know that you can destroy it, but if you don't it flies away and it is never established where it goes. I reckon it went to none other than moon.
Rocket two:
This rocket, I think, came from Call of the Dead. Also from the easter egg. A few steps in to the challenge you come across a UO (Unidentified Object) now I know that it is said that it is a submarine, but does anyone ever get proper look at the submarine? Think about it: It contains Richtofen's "Sex Toy" which is used on moon and Shangri-La, and how did it's angle get high enough to get to the top of the lighthouse and then downward when there is no way down unless it goes through the solid floor, which a normal beam of light could not do.
Rocket three:
First: go watch this and then listen to me say: I reckon this "Rocket" does go straight to the moon, I know it seems way too small to contain the zombies or the 115, but we aren't shown it up close, it could be any size and could just be far away.
So that's my theory on where the rockets came from I'll be back with more theories, map ideas, weapon ideas and more!