Earth’s air is 20 percent oxygen. The rest is stuff human bodies don’t need like nitrogen and argon. So Artemis’s air is pure oxygen at 20 percent Earth’s air pressure. That gives us the right amount of oxygen while minimizing pressure on the hulls. It’s not a new concept—it goes back to the Apollo days. Thing is, the lower the pressure, the lower the boiling point of water. Water boils at 61 degrees Celsius here, so that’s as hot as tea or coffee can be.
