There are no age restrictions for the NASA Astronaut Corps. Astronaut candidates have ranged between the ages of 26 and 46, with the average age being 34. Candidates must be U.S. citizens to apply for the program. There are three broad categories of qualifications: education, work experience, and medical. Candidates must have a
master's degree from an accredited institution in
engineering,
biological science,
physical science or
mathematics. The degree must be followed by at least two to three years of related, progressively responsible, professional experience (graduate work or studies) or at least 1,000 hours of pilot-in-command time in jet aircraft. An advanced degree is desirable and may be substituted for experience, such as a doctoral degree (which counts as the two years experience). Teaching experience, including experience at the
K–12 levels, is considered to be qualifying experience. Candidates must have the ability to pass the NASA long-duration space flight physical, which includes the following specific requirements: • Distant and near visual acuity: Must be correctable to 20/20, each eye separately (corrective lenses such as glasses are allowed) • The refractive surgical procedures of the eye,
PRK and
LASIK, are allowed, providing at least one year has passed since the date of the procedure with no permanent adverse after effects. • Blood pressure not to exceed 140/90 measured in a sitting position • Standing height between and ==Members==