What would it take for humans to survive on mars, without shelters, akin to the Martian, in terms of genetic engineering? Is it even remotely viable, or would some mechanical assistance (oxygen tanks?) still be needed?
For more background, assume that Earth is going to be uninhabitable, exact cause not yet determined, but Earth is going to be a no go, so humanity has to survive on Mars, we don't have enough time to terraform it, and putting down full shelters is not feasible due to limitations in the material that can be provided. Assume, that at most, the landing space vessels can be converted to shelters, for sleeping and storm protection, but also hydro/aero-ponics, but a large scale fully enclosed habitat or a dome are not viable, and can not cover the needs of the landed population (Which will number in the thousands), and the expected colony growth
Small scale local terraforming is being performed, but limited resources means it's going to be used to allow for farming.