You are making the assumption it is for long term habitation, which might not be the case. For long term habitation, you would solve it like any other engineer

You are making the assumption it is for long term habitation, which might not be the case. For long term habitation, you would solve it like any other engineering problem. How many people do you need to support, against what threats, for how long and what safety margins do you need. Air is a solved problem, you either pull/push from the outside environment and filter on its way in (open circuit), or you treat the air (closed circuit). Waste goes into a leech field or is incinerated. Electrical is generated / stored onsite or powered externally.