I also happen to believe that by the time many of the young people who are interested in space become adults that the astronaut corps as we know it will be part of history, sort of like the old government mail carrier pilots. Once space is opened up to all of us, there will be no need for the small, professional corps of NASA astronauts presently located in Houston, Texas. Plan on becoming a mission controller, a training manager, a propulsion engineer, a spacecraft designer, or any of a thousand jobs. Your position will be just as important as an astronaut, and you will love every day you go to work. Now, with all that said, let's take a look at the present requirements to be a NASA astronaut.
Pilots are usually former or current military jet pilots.
Test pilots are preferred. Mission specialists are scientists or engineers who will operate the experiments in space. You have to be in good physical shape, too. Typically, there are hundreds of applicants for every astronaut position available, so the competition is fierce. So there you are.