Margaret Rhea Seddon

Seddon was born in Murfreesboro, Tennessee, where she attended St Rose of Lima Catholic School and graduated from Central High School in 1965. She received a bachelor of arts degree in physiology from the University of California, Berkeley in 1970, and a doctorate of medicine from the University of Tennessee College of Medicine in 1973. While at the University of California, Seddon was a member of Sigma Kappa sorority.

Selected as an astronaut candidate by NASA in January 1978, Seddon became an astronaut in August 1979. Her work at NASA was in a variety of areas, including Orbiter and payload software, Shuttle Avionics Integration Laboratory, Flight Data File, Shuttle medical kit and checklist, launch and landing rescue helicopter physician, support crew member for STS-6, crew equipment, membership on NASA's Aerospace Medical Advisory Committee, Technical Assistant to the Director of Flight Crew Operations, and Capsule Communicator (CAPCOM) in the Mission Control Center.

She was Assistant to the Director of Flight Crew Operations for Shuttle/Mir Payloads. A three-flight veteran with over 722 hours in space, Seddon was a mission specialist on STS-51D (1985) and STS-40 (1991), and was the payload commander on STS-58 (1993). In September 1996, she was detailed by NASA to Vanderbilt University Medical School in Nashville, Tennessee. She assisted in the preparation of cardiovascular experiments that flew aboard Space Shuttle Columbia on the Neurolab Spacelab flight in April 1998. Seddon retired from NASA in November 1997. She is now the assistant Chief Medical Officer of the Vanderbilt Medical Group in Nashville, Tennessee.

In 2015, Seddon was inducted into the United States Astronaut Hall of Fame.