[hutzlibu]

With lenses you could also burn the soil to produce gases that add up to he atmosphere ... but we want breathable atmosphere. With lot's of oxygen and very little co2. And that is a bit harder ...

So you also couldn't just vaporize the ice, you need to split it up. Solar heat could be sufficient, but the water will then be missed everywhere else on mars where life wants to grow.

And Mars is dry.

So I would first use the water in enclosed habitats. And then after, if there is plenty of water left, one could start to think about smoking that up ..

But there might be other options, once you have lot's and lot's of autonomous machines and rockets available and allmost unlimited fuel (sun?). But without that? Not a chance ...

[larkeith]

I wonder if it would be a reasonable colonization process to establish a non-breathable atmosphere, allowing postprocessing facilities to later separate oxygen from airborne water vapour.

The notable benefits from such an approach would be the ability to easily deliver asteroid-based water deposits (aim it at Mars, let reentry do the rest), as well as the significant simplification of ground based colonization technology - it's far easier to build resilient habitats for a non-breathable atmosphere than it is for a vacuum, and the risk of accidents and difficulty of venturing outside is much, much lessened (a face mask or filter and oxygen tank instead of a bulky spacesuit), not to mention the radiation protection afforded by a thick atmosphere.

[hutzlibu]

True, I think I would agree, there are many immediate benefits.

But it has to be carefully considered, as it might hinder a longterm plan for a nice, breathable atmosphere.

But once we reach mars, we are probably busy first, with primitiv things such as life support ...