The other benefit to a settlement plan, is that you could send the habitat and tools ahead of time, to be assembled by robots. Which implies multiple missions,

The other benefit to a settlement plan, is that you could send the habitat and tools ahead of time, to be assembled by robots. Which implies multiple missions, which lowers per-mission weight requirements, and allows for habitat tests prior to having human life (and larger, more temperamental resources) on the line and for fixes to be bundled in subsequent missions.