"[A] lot of the tasks we have to do free-float. You're really working hard. You might watch an EVA [Extra Vehicular Activity, or spacewalk] and think, "Gosh, these guys are moving slow, and they're not working that hard." Inside the suit, you're constantly flexing all of your muscles to keep control. A good example: If you start translating [spacewalking], and then you go to stop—you put on the brakes with your hand—you're going to pitch up. Your feet are going to tend to fly up over your head. So you have to constantly sense any rates that your body might be getting on it, then put in a force to null that rate. So when you go to stop, you're stopping with one hand and you're pushing up with the other, so you don't pitch out of control."