Margaret Rhea Seddon (b.
1947) is a former NASA astronaut and physician. She flew as mission specialist, and
later payload commander, on three Space Shuttle flights.
She has a
Doctorate in Medicine from the University of Tennessee. Her NASA career began
in 1979, where she worked in a variety of fields, from organising medical
experiments to technical assistance. After retiring from NASA, she became the
assistant Chief Medical Officer of the Vanderbilt Medical Group.