It took hours for these things to spiral down from the stratosphere. During that time the shell had cooled off and purged any lingering fumes of SO 2 . The net runners would push the dolly over to a waiting trailer and hoist it into a cradle. Then they’d use the winches to reinstate the net. Downtime for a given net was rarely more than a few minutes. When a trailer got full of spent shells, a truck would drive up, hitch on, and tow it north to one of the installations that had been built along the arc road around Pina2bo. There each shell would be inspected and refurbished and sent empty to Pina2bo itself, where it would sit in the queue awaiting its next flight. Only at the last minute was the hot liquid sulfur piped into its tank.