Heck, it's hard getting to the nearest planet. There was an interesting thread last week, where scientists are discussing sending bacteria carrying our DNA to other planets. Since it's hard to send people, the plan would be to send robotics that would 3d-print humans after extracting our DNA encoded in the bacteria. We can't go, but we can propagate the species elsewhere, perhaps in conjunction with terraforming a planet. This is far into the future, not in our lifetime (at least while we have Obama-types running things down here).
Simple propagation of the species isn’t my only concern for the future, but since we’re the only sentient species we’re currently aware of, it might be nice to preserve it.