Hiroko and her biosphere team were the last ones in, banging through the hatch a full twenty-seven minutes after the initial alarm. They hurtled into the weightless space flushed and out of breath. “Has it started yet?”

“Not yet.”

They plucked personal dosimeters from a velcro rack of them, and pinned them to their clothing. The rest of the crew already floated in the semicylindrical chamber, breathing hard and nursing bruises and a few sprains. Maya ordered them to count off, and was relieved to hear the whole hundred run through without gaps.

The room seemed very crowded. They hadn’t gathered the whole hundred in one spot for many weeks, and even a max room didn’t seem large enough. This one occupied a tank in the middle strand of the hub shaft. The four tanks surrounding theirs were filled with water, and their tank was divided lengthwise between their room and another semicylinder that had been filled with heavy metals. This semicylinder’s flat side was their “floor,” and it was fitted inside the tank on circular tracks, and rotated to counteract the spin of the ship, keeping the tub between the crew and the sun.

So they floated in a nonrotating space, while the curved roof of the tank rotated over them at its usual four rpm. It was a peculiar sight, which along with the weightlessness made some people begin to look thoughtful in a preseasick kind of way. These unfortunates congregated down at the end of the shelter where the lavatories were located, and to help them out visually, everyone else oriented themselves to the floor.