He remembered people asking difficult questions around the time of Sean’s departure for the L1 gate. What the hell was this crazy billionaire doing? Clearly, it was not part of the official plan. The official plan did not seem to recognize a need for a huge piece of ice. But Sean Probst believed it was so important that he was willing to go up there personally and take care of the problem. There was a good chance he would die in the process, or come back so broken from radiation exposure and long-term weightlessness that his health would never recover. And so people had asked Doob what he thought Sean was thinking. And Doob, who hadn’t studied it at the time, had answered vaguely, saying that water was always a good thing to have in space: you could drink it, grow crops with it, use it for radiation shielding, split it into hydrogen and oxygen for rocket fuel, or pipe it through hoses to radiate excess heat into space. All of which was quite true, but sort of begged the question. It was so blindingly obvious that NASA must have thought of it already. What additional demand for water was Sean Probst seeing that NASA had failed to notice, or turned a blind eye to?