Once you are assigned to a flight, the whole crew is assigned at the same time, and then that crew trains together for a whole year to prepare for that flight.

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.

Eventually private enterprise will be able to send people into orbit, but I suspect initially it's going to have to be with NASA's help. Whether it's going to be a consortium or one entity remains to be seen. I could be wrong. I could be one of the old fogies! Rocket science is tough, and rockets have a way of failing. It happens. A company has to be willing to bear the risk of its rocket failing. It's a very large capital investment.

Three Secrets to Success: Be willing to learn new things. Be able to assimilate new information quickly. Be able to get along with and work with other people.

It takes a few years to prepare for a space mission.

I didn't really decide that I wanted to be an astronaut for sure until the end of college.

Different astronauts sleep in different ways.