Margaret Rhea Seddon (born November 8, 1947) is a physician and retired NASA astronaut. After being selected as part of the first group of astronauts to include women, she flew on three Space Shuttle flights: as mission specialist for STS-51-D and STS-40, and as payload commander for STS-58. Both before and after her career in the astronaut program, she has been active in the medical community in Tennessee, Mississippi and Texas.

Early life and educationEdit

Seddon was born in Murfreesboro, Tennessee, where she 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.[1]

After medical school, Dr. Seddon completed a surgical internship and 3 years of a general surgery residency in Memphis with a particular interest in nutrition in surgery patients. Between the period of her internship and residency, she served as an Emergency Department physician at a number of hospitals in Mississippi and Tennessee, and served in this capacity in the Houston area in her spare time. Dr. Seddon has also performed clinical research into the effects of radiation therapy on nutrition in cancer patients.

NASA experienceEdit

Selected as an astronaut candidate by NASA in January 1978, Dr. Seddon became an astronaut in August 1979. Her work at NASA was in a variety of areas, including Orbiter and payload software, Space 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.[2][3]

She was Assistant to the Director of Flight Crew Operations for Shuttle/Mir Payloads. A three-flight veteran with over 722 hours in space, Dr. 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 which flew aboard Space Shuttle Columbia on the Neurolab Spacelab flight in April 1998. Dr. Seddon retired from NASA in November 1997. She is now the assistant Chief Medical Officer of the Vanderbilt Medical Group in Nashville, Tennessee.

Space flightsEdit

Margaret Rhea Seddon

Portrait from 1978

STS-51-D (Discovery), April 12–19, 1985, was launched from and returned to land at the Kennedy Space Center, Florida. The crew deployed ANIK-C for Telesat of Canada, and Syncom IV-3 for the U.S. Navy. A malfunction in the Syncom spacecraft resulted in the first unscheduled EVA (spacewalk), rendezvous and proximity operations for the Space Shuttle in an attempt to activate the satellite using the Remote Manipulator System. The crew conducted several medical experiments, activated two "Getaway Specials," and filmed experiments with toys in space. In completing her first space flight Dr. Seddon logged 168 hours in space in 109 Earth orbits. It was on this mission that Dr. Seddon took the badge of her sorority Sigma Kappa into space.[4]

STS-40 (Columbia) Spacelab Life Sciences (SLS-1), June 5–14, 1991, a dedicated space and life sciences mission was launched from the Kennedy Space Center, Florida, and returned to land at Edwards Air Force Base, California. During the nine-day mission the crew performed experiments which explored how humans, animals and cells respond to microgravity and re-adapt to Earth's gravity on return. Other payloads included experiments designed to investigate materials science, plant biology and cosmic radiation, and tests of hardware proposed for the Space Station Freedom Health Maintenance Facility. Mission completed in 146 orbits of the Earth, and logged her an additional 218 hours in space.

STS-58 (Columbia), Spacelab Life Sciences-2, flew October 18 to November 1, 1993. Dr. Seddon was the Payload Commander on this life science research mission which received NASA management recognition as the most successful and efficient Spacelab flown to date. During the fourteen day flight the seven-person crew performed neurovestibular, cardiovascular, cardiopulmonary, metabolic, and musculoskeletal medical experiments on themselves and 48 rats, expanding our knowledge of human and animal physiology both on earth and in space flight. In addition, the crew performed 10 engineering tests aboard the Orbiter Columbia and 9 Extended Duration Orbiter Medical Project experiments. The mission was accomplished in 225 orbits of the Earth in over 336 hours.


She is married to former astronaut Robert L. Gibson of Cooperstown, New York with three children: Paul, Dann, and Emilee. Her father, Mr. Edward C. Seddon, resides in Murfreesboro. Her mother, Mrs. Clayton Dann Seddon, is deceased. His mother, Mrs. Paul A. Gibson, resides in Seal Beach, California.


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