The Big Ride was the third of the basic options. It meant to boost Izzy in its entirety—Amalthea and all—to a much higher orbit. It had been considered implausible because of the amount of propellant that would be needed. Not just implausible but—absent the timely return of Ymir —physically impossible. Despairing of Sean’s chances, its supporters had lately tended to suggest scaled-down variants, such as reshaping a small percentage of Amalthea into bolide deflectors and ditching most of its mass.