Humans were evolved to survive in a razor-thin sliver of Earth's atmosphere and nowhere else. We aren't designed for and don't belong in deep space.

We should genetically engineer smart creatures that can fare better out there, creatures with enormous capacities for cancer resistance, stupefyingly impressive energy efficiency, and staggeringly long lifetimes. They don't need all of our gravity-influenced skeletal structure and musculature. The fact that we're air-breathers is a particularly worrisome liability for being a space-faring critter. Little holes in our tin can atmospheres can lead to explosively bad results.

I'd start with something closer to an octopus and then throw (even more) intelligence at it.