There’s a huge amount of pressure on every astronaut, because when you get right down to it, the experiments that are conducted on a space flight, or the satellites that are carried up, the work that’s to be done, is important and expensive work, and you are up there for a week or two on a Space Shuttle flight. The country has invested a lot of money in you and your training, and the Space Shuttle and everything that’s in it, and you have to do things correctly. You can’t make a mistake during that week or two that you’re in space. Anything from making a mistake on an experiment that would ruin some scientist on earth’s experiment — career, potentially — to doing something wrong with the satellite that a country was depending on for its communications, to making some mistake that could actually cost you and the crew either a mission or your lives. So there is a lot of pressure that’s put on every astronaut to just make sure that he or she understands exactly what to do, exactly when to do it, and is trained and prepared to carry it out.