Sure, many. It's a huge challenge. Not impossible. If we'd set it as goal, we could develop the technology and science as we go. I'm sure humanity is inventive enough. I mean, we did go to the moon with 60's technology...

But even thinking ahead more than 2 years seems impossible these days, everything is focused on the now and short-term profit. Anyway, rant over, it's nice to think big instead of small once in a while :)