In the future, the United States along with some international partners, Japan, Canada, Russia, and the European Space Agency, will operate a man tended space station. From the orbiting space station, humans will continue journeys to Mars, the moon, and other planets. While these plans are taking place, there will be more need for qualified space flight professionals.

NASA continually accepts applications for the Astronaut Candidate Program. Military and civilian personnel are considered  program. About every two years candidates are selected for pilot and mission specialist categories as needed.

MISSION SPECIALIST REQUIREMENTS:
Bachelor's degree in engineering, biological science, physical science, or mathematics from an accredited institution. Three years of professional experience in related area or master's degree = 1 year of work experience, doctoral degree = 3 years of experience
Passing of NASA Class II space physical which includes the following standards:
    Visual-distance acuity-20/200 or better uncorrected, correctable to 20/20 each eye
    Blood pressure-140/90 in a sitting position
    Height between 58.5 and 76 inches
Applicants who meet these basic qualifications are evaluated by discipline panels. Finalist are screened during a week long process of interviews , thorough medical examination, and orientation. The Astronaut Board's recommendationsare based on there education, training, and experience as well as unique qualifications and skills because hundred of applicants fulfill the reuirments the final selection is based on personal interviews. Astronauts are expected to be team players and highly skilled generalist with just the right amount of individuality and self-reliance to be an effective crew member.    
     Selected applicants are designated astronaut candidates are assigned to a astronaut office at Johnson Space Center for 1 to 2 year of training evaluation program. Civilian candidates who successfully complete the training are selected astronauts and are expected to remain with NASA for at least 5 years. Successful military candidates are detailed to NASA for a special tour of duty.