There are totally docking stations near the surface for outriders, even though the big ships would only be able to dock in space or land on the surface. The atmosphere of the planetoid is thin, but breathable with gas masks. (Once you get inside it's just plain breathable.)

A small outrider could make it further in, at least into the larger, main corridors, but the problem then would be finding a place to park. (And security would totally try to impound the illegally parked outrider.)