Tom Marshburn

Dr. Tom Marshburn is a retired NASA astronaut and board-certified emergency medicine physician whose career encompasses the full spectrum of human spaceflight, from providing medical care to crews on the ground to commanding the International Space Station in orbit. Marshburn is a veteran of three spaceflights to the International Space Station and is among the few individuals to have flown on three different spacecraft: Space Shuttle, Russian Soyuz, and SpaceX Crew Dragon. He spent 337 days in space and performed five spacewalks during his missions. Marshburn holds the record as the oldest person to perform a spacewalk, achieving this at age 61.

Marshburn holds a Bachelor of Science in physics from Davidson College, a master's in engineering physics from the University of Virginia, a Doctorate of Medicine from Wake Forest University, and a master's in medical science from the University of Texas Medical Branch. He completed his residency in emergency medicine in Toledo, Ohio, where he served as a Life Flight physician, treating critically ill patients in the field. Marshburn was part of the inaugural class of the University of Texas Medical Branch in Galveston's Space Medicine Fellowship and subsequently became a NASA flight surgeon, providing medical care to astronauts. He was assigned to the NASA-Mir program, completing extended tours in Russia and becoming fluent in Russian.

After a decade as a flight surgeon and multiple applications, Marshburn was accepted into the NASA Astronaut Corps. He served as a mission specialist on STS-127, a 16-day mission on Space Shuttle Endeavour to the International Space Station, performing three spacewalks to install an experimental platform on the Japanese module and replace industrial batteries. On his second mission, aboard the Russian Soyuz as part of Expeditions 34 and 35, Marshburn and crewmate Chris Cassidy conducted an emergency spacewalk to repair an ammonia leak threatening the space station, setting an American record for the shortest preparation time for a spacewalk.

Marshburn piloted the NASA SpaceX Crew-3 mission to the International Space Station, served as a flight engineer on Expedition 66, and was commander of Expedition 67. During these missions, Marshburn and his crewmates conducted more than 250 scientific investigations focused on advancing human spaceflight and supporting future exploration. Marshburn retired from NASA after 28 years, including 18 years as an astronaut. He is the recipient of the NASA Superior Achievement Award, the Space and Life Sciences Division Special Space Flight Achievement Award (twice), and the Lyndon B. Johnson Space Center Superior Achievement Award.

Following his NASA career, Marshburn has contributed to the commercial space industry as chief astronaut and vice president of human factors engineering for Sierra Space, where he leads the Sierra Space Human Spaceflight Center and oversees human factors engineering and astronaut health planning. He also serves as a clinical assistant professor of aerospace medicine at the University of Texas Medical Branch. Marshburn frequently speaks on topics related to space exploration, aerospace medicine, leadership, and resilience, drawing on his experience in emergency medicine and human spaceflight.