The initial key to a successful out-migration of humans into the solar system and the larger universe, is to develop the ability to prepare the ground ahead of human colonists. When human settlers arrive on Luna, Mars, Titan, and other potential colonies, they should find working habitats and vital infrastructure waiting for them.
Here are a few basic ideas on complex systems and autopoetic self-organisation which will likely form the foundation for more advanced techniques of seeding complex systems in hostile environments. The slides come from Rene Doursat, who lectures at Ecole Polytechnique and specialises in complex systems and morphogenetic engineering.
Such novel complex systems could serve to allow the survival and prospering of humans in locations which would ordinarily not support such complex animals which evolved in a much more suitable location (Earth) for their needs. In other words, the "seeds" of human-enabling complex systems could be delivered to hostile -- but strategically important -- locations, where they will proceed to build human-friendly micro-environments, habitats, and infrastructures.
Naturally, there is the opposite approach which must be considered: A re-designed human animal more suited for the hostile environments likely to be met in space and on other space bodies.
Rene Doursat has looked at biological design (PDF) in ways which might be applied to such a project, in the future.
Such concepts can be applied to biological bodies AND biological brains, as well. In fact, the functioning of the human brain itself is a good example of decentralisation, emergence, and self-organisation -- a prototypical complex network.
So while human designs up until now have tended to possess rather simple and straightforward architectures, at the same time humans are capable of comprehending the nature of complex, evolved systems. The idea of incorporating the properties of complex systems into human designs is not so far-fetched, perhaps in part because of the way our brains work.
The understanding and harnessing of complex systems to human purposes, is a grand project. It is worth spending a good deal of time on, in the future.