Their slowness was part of the problem. If the debris cloud was a fleet of cars roaring around a circular raceway at top speed, then Endurance was a child toddling out into traffic. That extreme disparity in speed would remain until the next apogee, ten days from now, when they would make their biggest and longest burn, expending all of Endurance ’s remaining propellant to accelerate her to the same average speed as the debris cloud. In so doing, they’d convert the dual-hairpin orbit into a nearly perfect circle, remaining 384,512,933 meters from Earth forever. Having merged smoothly with the traffic on the circular raceway, they would go hunting for Cleft. Doob had spied it several times on his optical telescopes, gotten a fix on its params, knew how to find it.