Has there been any major occurrences between NOW and THEN? World war or the like? That's your job to set the scene for us leaving earth as natural disasters is all a bit vague. I wouldn't think that would be enough for a planetary Exodus of this scale.
Well, when I first started conceiving the plot, there were no real disasters, save for the fact that all the near-Earth colonies (Moon, Mars, Europa, Titan) all were near-failures. There was a point when it wasn't certain this story-line would even be used for the game, so I created an alternative version for my own use just in case. However, this kind of exodus still needs some sort of event to spur the need, I think (regardless of what Cameni or Angrypig might say to that
, but that's just MHO).
The only thing I can say about the
alternate plot I created was that a small cometary body impacted the moon, completely wiping out the dozen or so colonies we had established there. The fallout from the impact eventually rained down on the Earth, destroying or damaging a number of major cities as well. The general consensus from the scientific community was that this could have been an Extinction Level Event, so plans were drawn up to insure humanity's survival.
There are a few other things that happened, but some of them may be used for the hidden plot of the game, so are classified Above Top Secret for now
For right now though, none of it's really necessary for the mechanics of the game, so it's being kept intentionally vague. I'm sure Cameni and Angrypig will reveal some of it in the near future though.
As for your idea, I like it, but I think it should be in the realm of days instead of hours for some of the more advanced tech. Some structures, like perhaps a Fusion Reactor, should take a few weeks of game-time, if not months. Although if multiplayer is allowed, multiple characters working together should be able to reduce that time. But again, that belongs in a different thread.