Lunar Liner, sometime in the 2100s. The whole ship would spin around its axis to provide some artificial gravity to the six inflatable passenger modules. The ship would be boosted via space tug to the moon, then return to pick up more passengers before being boosted again. Maximum passenger capacity is 48, but setting up multiple ships on the line would provide consistent passage to the moon, where transfer capsules would take passengers to orbiting stations where they could take landers down to the surface, or stay in lunar orbit.