At this point I’m still more interested in building something permanent on the moon or getting to mars.
Until we can manage a permanent human presence on the Moon, there’s not much point in heading for Mars. But a big booster will be needed regardless of what we’re doing with crewed missions. :’) IMV, we should plant the flag on every solar system body where it’s possible — eventually. IOW, Mars, Mercury, maybe some of the other moons of the gas giants, and (to get ready for the latter), the asteroids. I think what will happen instead is a swarm of USV (unmanned space vehicles, basically probes of high functionality and some autonomy, but small-sized) to assay all the large asteroids, beginning with the Earth-crossers.