Given that it was a cylinder with a fifty-six-mile radius, from close up the outer shell had the appearance of a flat wall. Directly ahead of the Boojums, a huge space dock stood open. Massive reinforced doors seemed to be there only for emergencies; we’d never seen them move since we began surveillance. The Boojums drifted in, small attitude jets giving occasional puffs as they corrected their individual vectors. Eventually the crafts drifted into docking bays designed specifically for them. An army of small service bots stood ready to receive the arrivals.