I'm with Cog and Arch on this one. As I have previously argued over the years, humans won't be colonizing any planets. Trans- and post-humans will. Sure, maybe there will be a small human base in Mars or the Moon or semi-autonomous space station by 2040, but a base is not colonisation.
Sending fragile, needy meat packages to space is just too inefficient. They require tons of food, water, air, they poop, go crazy in confined spaces, their muscles atrophy, they get sick and grow old, need to sleep 1/3 of their lives, and are often stupid too. Why create an expensive, complex support ecosystem for an inferior organism instead of creating an organism adapted to space? Like multicellular life crawling out of primordial soups and out of the seas evolving for land, and even flying, so too shall we only succeed in living off this planet in a shape that fits our new environments.
Pioneer probes launched in 1972 finally lost contact in 2003. That's 31 years. The voyager probes are supposed to still be working until 2025. That would be 48 years of operation. That was with 1970s tech. I don't know how a human could survive space travel 3+ decades in a machine no larger than a small car, not with present tech, nor with any tech I know in development. Even if something like cryogenic hybernation turned out to work, it would still be inconvenient and expensive, when a drone could record and process far more data than a human without requiring much for its sustenance.
When a drone with sufficient sensors is developed and plugged into the nervous system of a person, providing some concrete out-of-body experiences, then people will finally start to abandon the childish dream of primates in space.