Peggy Whitson

Peggy Whitson was born in 1960 in the small farming community of Mount Ayr, Iowa, and grew up on the family farm in a state better known for corn than cosmonauts. She earned a bachelor's degree in biology and chemistry from Iowa Wesleyan College and went on to complete a Ph.D. in biochemistry at Rice University in Houston. Rather than reaching space by way of the cockpit, Whitson came through the laboratory: she spent years at NASA's Johnson Space Center as a research biochemist and project scientist, working on the science that flies aboard spacecraft, before NASA finally selected her as an astronaut candidate in 1996 after several earlier applications.

Her spaceflight career spans the entire modern era of the International Space Station and the dawn of commercial crews. On her first mission in 2002, she flew to the ISS aboard Space Shuttle Endeavour (STS-111) and lived on the station for 184 days as a flight engineer and the first NASA Science Officer during Expedition 5. She returned in 2007 aboard Soyuz TMA-11 for Expedition 16, a 191-day stay during which she became the first woman to command the International Space Station. Her third long-duration flight, Expeditions 50/51/52 in 2016-2017, ran 289 days and made her the first woman to command the station a second time. She then retired from NASA but not from spaceflight, joining Axiom Space to command private missions: Ax-2 in 2023, which carried the first Saudi astronauts to the ISS, and Ax-4 in 2025 aboard Crew Dragon 'Grace', which brought the first station visitors from India, Poland, and Hungary. Across her career she performed ten spacewalks, the most of any woman.

By the close of her Ax-4 flight in July 2025, Whitson had accumulated roughly 695 days off the planet — the most cumulative time in space of any American astronaut and any woman, extending a record she has held and rebuilt across two decades. Now retired from NASA and flying commercially, she stands as a bridge between the government-run space station era and the emerging age of private orbital missions, having commanded both. A biochemist who reached the pinnacle of a domain long dominated by test pilots, she is a persistent advocate for STEM education and for women in science, and her career remains a benchmark against which the endurance and leadership of American astronauts are measured. Her own summary of that path is characteristically plain: anything is possible if you put your mind to it.