System ready
Launch is a solved problem. What happens in the four hours, four months and four years afterward is not.
One-sixth g is not a smaller version of Earth gravity. It is a different design problem with its own rules.
A closed loop is never quite closed. The engineering is in managing the leak.
A base is not infrastructure. A schedule is.
When the round trip is measured in months, you do not ship what you need. You ship what you will need.
Flying twice is a demonstration. Flying fifty times on the same schedule is a business.