Okay...here’s a follow up to that. One idea about how to make Mars habitable is to melt the ice caps, thereby freeing CO2 and H2O into the atmosphere. This would cause a runaway greenhouse effect freeing more CO2 from the regolith. This would in effect raise Mars’ atmospheric pressure to something that we could reasonably work in in a shirt-sleeve environment, except with breathing masks/air tanks. If the ice caps melt, with this process start?No. Due to its lower density and smaller diameter, Mars has little atmosphere (surface pressure is about what the pressure is above Earth at 40 miles altitude; space is defined as 50 miles). The way to work in a shirtsleeve environment on Mars is to deploy inflatable plastic domes (like a plastic bag greenhouse), and carry repair kits to deal with the tiny pebbles of space debris which hit Mars on a regular basis.
I’ve heard an interesting proposal in this regard by Richard P. Speck of Micro-Space Inc. Now it does seem a little crazy, but he proposes sending a “camping” expedition to Mars, where the day-to-day operations would be carried out in a portable inflatable tent, now supplies would have to be landed, and I think he proposes a single site “depot” that you would enter, pick up your box of supplies, and go out to the tent. I propose a “dog sled” type mission along the same vain. Although I don’t know how you would reconcile that with being able to anytime abort to orbit...