When we’re simulating deorbit to landing, for instance, dozens of people observe, hoping that something new—a flaw in a standard procedure, say, or a better way of doing something—will be revealed. They actually want us to stumble into a gray zone no one had recognized could be problematic in order to see whether we can figure out what to do. If not, well, it’s much better to discover that gray zone while we’re still on Earth, where we have the luxury of being able to simulate a bunch more times until we do figure it out.
