In Surviving Mars, perhaps the most important resource for your colonists is oxygen. While colonists can get by without food and water at least for a while, without oxygen, they will quickly die in just a few hours. Fortunately, of all the basic resources needed to house humans, oxygen is the easiest to obtain.
All you have to do is build a MOXIE, a special oxygen production building. Its cost is 5 metal, and after creation, the building must be connected to the dome or to the oxygen storage using pipes. To connect them properly, click on Pipes and then left click from MOXIE to whatever you want to connect to. Keep in mind that only certain sections of domes and other buildings (indicated by the blue and yellow symbol) can be connected to the pipe. If you have everything connected correctly, you will see a quick notification that says "Connected to building" - otherwise you created a pipe to nowhere.
