"Maneuvering" conjured images, in nontechnical minds, of football players weaving among their opponents in an open field. What the Arkitects had in mind was considerably more sedate. Izzy would never be agile. Even if she were, maneuvering in that sense would waste a lot of fuel. If an incoming rock big enough to destroy her were detected long enough in advance, she could get out of its path with a thruster burn so deft that most of her population would not even know it had happened. So, the optimistic view of how this was going to work was that Izzy would remain in something close to her current orbit, with occasional taps on the thrusters that would move her out of the way of any dangerous bolides hours or days in advance of the projected collision. The analogy was made to an ocean liner gliding through a field of icebergs, avoiding them with course changes so subtle that the passengers in the dining room wouldn’t even see the wine shifting in their crystal stemware.