Firstly, is that "2066" underneath the Federal flag the date??? Holy crap, is FTL invented tomorrow in your timeline?
Speaking of FTL, this whole thing assumes that it exists--along with some sort of antigravity and/or reactionless drive--and is hella quick; after all, a colony isn't going to remain part of the US if it takes twenty years to get a message back and forth. Not to mention the whole concept of importing beef from another star system--rocket fuel is expensive, so obviously they're using something other than that.
As for planets orbiting opposite each other (in the same orbit, I presume that means), that's not exactly the most stable of formations. It would be better for them to be a double-planet or two planets in the habitable zone of the same star or something.
So the colonies are being saddled with shipload after shipload of refugees. Okay, I can buy that. But FTL technology is still brand spanking new--remember what the first generation of iPod and Xbox was like? Hell, the first steam engine probably needed to be shut down and restarted constantly, as well! FTL is magic, of course, so you can have it work however you like, but I think it would snap suspension of disbelief in half if the first starships work perfectly the first time like they were handed down to us from the archangels--if they have to do that, might I suggest finding them in some alien ruins on the moon or something? We're talking something that's not even theoretically possible here, after all--not by a long shot--and you have it happening before most of us picture us having a moon base, after all.
Aliens or no aliens and disaster or no disaster, I'd stretch out the time frame to a few centuries. I mean, we're talking less than thirty years between first touchdown and "present" and you have each colony having a fully-established cultural identity. Probably much less. And I noticed a map of a fully-terraformed Mars that seemed connected, which isn't happening this century.