I was thinking it might be possible to add a mod where you can visit the moon and mars from the Mothership Zeta DlC. The way it works is that you can use something similar to a shuttle, and fly yourself over there. In order to go there though, the spacesuit must be equipped by your character in order to avoid getting killed upon exiting the shuttle. While the surface has mutated, so has the moon and mars. There are ghouls and nightcrawlers that have finally gotten out of hibernation due to your arrival. There is also a moon base with a crew that has been cryogenically frozen prior to the war. Getting to the moon was relatively easy, but due to a crash landing you are now marooned on Mars until the shuttle is repaired. On Mars there are mutant versions of bloatflies and molerats to be on the look out for as you make your way through the reddish surface looking for anything that can replace the broken parts. Scattered throughout the surface are remnants of old crashed satellites with parts still intact.
What do you think of the idea? Is there anything I need to tweak? I was inspired by these moon terrain textures.
http://www.nexusmods.com/fallout3/mods/21064/?