No disrespect for the USAF intended, but there are a lot of astronauts who are neither in the military nor pilots.

Taking the liberty of quoting from a JSC Web page on astronaut selection and training (http://www.jsc.nasa.gov/pao/factsheets/nasapubs/9707006.html):

Mission specialists have similar requirements to pilot astronauts, except that the qualifying physical is a NASA Class II space physical, which is similar to a military of civilian Class II flight physical and includes the following specific standards: for vision-distance visual acuity - 20/200 or better uncorrected, correctable to 20/20, each eye. For Blood pressure-Same as for Pilots. Height requirements for mission specialists are between 58.5 and 76 inches.

The application package may be obtained by writing to the Astronaut Selection Office, Mail Code AHX, Johnson Space Center, Houston, TX 77058-3696.

Cheers...