[nwah1]

Not true. We've had sufficient technology for a long time. We've been sending robots to Mars for decades.

We just haven't made it an objective to terraform Mars. We've even been quite cautious about avoiding even the possibility of transporting microbes there and "contaminating" it.

But the basic mechanics of how to terraform are known. Elon Musk mentioned nuking the poles of Mars as an option. Changing the gas composition could be done, albeit slowly, with enough resources and motivation. You can send robots in advance of human settlers to prepare things.

Self-replicating robots would be more ideal, and that is not a solved problem, but you could likely build partially self-replicating robots that are replenished with "vitamins" much like how the RepRap project does.

Various NASA theorists have written about such things

http://www.islandone.org/MMSG/aasm/