I reject the premise, and this false idea that everything that benefits the rich harms the poor and vice versa. The world does not have a finite amount of wealth that can either be distributed evenly or unevenly. Capital generates capital and it is easier to bring the poor up if you don't try to do it by dragging the rich down.
In the real world if there was an 'Elysium', there may be a paradise that only the rich can afford to live on, but those of us left down on Earth would sure benefit from building it, maintaining it, then trading with it, ending up richer than they were before. It's easy to blame the rich for being poor, until they invest their money in a company and that company gives you a job.
And I don't think man has a 'destiny' to expand, but we'd sure be a stronger race for expanding into space. You know, exploring the final frontier. To explore strange new worlds, to seek out new life and new civilizations, to boldly go... It's not an entirely pragmatic argument and doesn't have to be. We should expand into space because it's there