To be selected as a pilot astronaut candidate an applicant must meet a number of basic qualification requirements. A bachelor's degree in engineering , biological science , physical science or mathematics is required. A graduate degree is desired, although not essential. The applicant must have had at least l,000 hours flying time in jet aircraft. Experience as a test pilot is desirable, but not required.
Many astronauts are mission specialist astronauts .
The space shuttle has seven seats but only two are involved in flying the shuttle. Mission specialist astronauts, working closely with the commander and pilot, are responsible for coordinating on board operations involving crew activity planning, use and monitoring of the Shuttle's consumables, and conducting experiment and payload activities. Academically, mission specialist astronauts must have a bachelor's degree in engineering, biological science, physical science or mathematics plus at least 3 years of related and progressively responsible professional experience. In regards to being realistic about your chances of flying in space, you must have a backup plan. Your backup plan might be to become an aerospace engineer, a test pilot, a scientist, a spacecraft designer, a software engineer, a flight test engineer, a simulation engineer, or a Martian geologist.