NASA Job openings., page 1

Qualifications for an astronaut:
Basic Qualification Requirements
Applicants must meet the following minimum requirements prior to submitting an application.

Mission Specialist Astronaut Candidate:
Bachelor's degree from an accredited institution in engineering, biological science, physical science, or mathematics. Degree must be followed by at least three years of related, progressively responsible, professional experience. An advanced degree is desirable and may be substituted for part or all of the experience requirement (master's degree = 1 year of experience, doctoral degree = 3 years of experience). Quality of academic preparation is important.
Ability to pass a NASA space physical, which is similar to a military or civilian flight physical and includes the following specific standards:
Distance visual acuity: 20/200 or better uncorrected, correctable to 20/20, each eye.
Blood pressure: 140/90 measured in a sitting position.
Height between 58.5 and 76 inches.

Pilot Astronaut Candidate:
Bachelor's degree from an accredited institution in engineering, biological science, physical science, or mathematics. An advanced degree is desirable. Quality of academic preparation is important.
At least 1,000 hours pilot-in-command time in jet aircraft. Flight test experience is highly desirable.
Ability to pass a NASA space physical which is similar to a military or civilian flight physical and includes the following specific standards:
Distant visual acuity: 20/100 or better uncorrected, correctable to 20/20 each eye.
Blood pressure: 140/90 measured in a sitting position.
Height between 64 and 76 inches.

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Notes on Academic Requirements
Applicants for the Astronaut Candidate Program must meet the basic education requirements for NASA engineering and scientific positions - specifically: successful completion of standard professional curriculum in an accredited college or university leading to at least a bachelor's degree with major study in an appropriate field of engineering, biological science, physical science, or mathematics. The following degree fields, while related to engineering and the sciences, are not considered qualifying:

Degrees in Technology (Engineering Technology, Aviation Technology, Medical Technology, etc.)
Degrees in Psychology (except for Clinical Psychology, Physiological Psychology, or Experimental Psychology which are qualifying).
Degrees in Nursing.
Degrees in Exercise Physiology or similar fields
Degrees in Social Sciences (Geography, Anthropology, Archaeology, etc.).
Degrees in Aviation, Aviation Management, or similar fields

Here's more info about being an astronaut:
www.nasajobs.nasa.gov...

I'd most thoroughly flunk the eye exam (mine is 20/700 uncorrected)