Peggy Whitson(1960 — ?)
Peggy Whitson
États-Unis
8 min read
An American NASA astronaut, Peggy Whitson is the woman who has spent the most time in space (665 cumulative days). She commanded the International Space Station on two separate occasions.
Frequently asked questions
Key Facts
- 1998: first spaceflight, aboard the Mir space station
- 2002: first female commander of the ISS, during Expedition 16
- 2017: breaks the American record for cumulative time in space (534 days), eventually reaching 665 days
- Completed 10 spacewalks, a record for a woman
- Holding a doctorate in biochemistry, she conducted numerous scientific experiments in orbit
Works & Achievements
With 665 days spent in orbit, Whitson holds the world record for cumulative time in space by a woman. This record reflects her exceptional contribution to understanding the physiological effects of long-duration spaceflight.
Whitson became the first woman to command the International Space Station, leading an international crew through five spacewalks. A historic first in the history of human spaceflight.
Throughout her missions, Whitson conducted dozens of experiments studying how weightlessness affects cells, bones, muscles, and the cardiovascular system, informing the protocols for future journeys to Mars.
Whitson commanded the first fully commercial crewed mission to the ISS aboard a SpaceX Crew Dragon, opening a new era of private access to space. At 62, she proved that age is no barrier to exploration.
As head of NASA's Astronaut Corps, Whitson oversaw the selection, training, and assignment of all American astronauts, underscoring the breadth of her influence within the space agency.
Whitson performed 10 spacewalks totaling more than 60 hours of extravehicular activity — a world record for a woman — including critical repairs to the exterior hull of the ISS.
Anecdotes
In 2017, floating aboard the ISS, Peggy Whitson received a live call from President Donald Trump, who congratulated her for breaking the American record for cumulative time in space (534 days). She replied from orbit that pushing the boundaries of human achievement is exactly what astronauts train for. This symbolic exchange, broadcast live, illustrated the connection between space exploration and national pride.
Peggy Whitson did not follow a straight path to the stars: she applied to NASA twice before finally being selected in 1996. The daughter of farmers from Iowa, she was inspired by the Apollo 11 moon landing in 1969, when she was just 9 years old. That evening, she decided she wanted to become an astronaut — a dream she never gave up.
During her long-duration missions, Whitson conducted biochemistry research on the effects of microgravity on the human body — including bone and muscle loss. This work, directly related to her doctoral thesis at Rice University, helped scientists understand how to maintain astronaut health during future voyages to Mars. She thus combined the roles of scientist and explorer.
In 2022, at age 62, Peggy Whitson returned to space aboard a SpaceX Crew Dragon capsule as part of Axiom Space Mission 1 — the first entirely private mission to the ISS. She served as its commander, becoming the astronaut who has commanded the greatest number of missions to the Space Station. She proved that the era of commercial exploration is very much real.
Whitson holds the record of 10 spacewalks for a female astronaut, totaling more than 60 hours in the vacuum of space. Each EVA requires hours of preparation, a 130 kg suit, and considerable risk. During one of them, she helped repair a critical system on the ISS, demonstrating that technical skill matters more than gender in space.
Primary Sources
Peggy A. Whitson was selected as an astronaut candidate by NASA in December 1996. She has a Ph.D. in biochemistry and served as Chief of the Astronaut Office. She has logged 665 days in space over the course of four missions.
Commander Whitson led the Expedition 16 crew aboard the International Space Station from October 2007 to April 2008, becoming the first woman to command the ISS. The mission included five spacewalks totaling 33 hours and 46 minutes.
Whitson described the experience of spending nearly a year in space as transformative, noting that scientific research conducted aboard the ISS directly informs the planning of future deep space exploration missions.
During a live call from the ISS, Whitson stated: 'We're so fortunate to be able to continue to do this research up here, and hopefully we'll break more records as we continue to push the boundaries of what humans can do.'
Key Places
Small rural town in Iowa where Peggy Whitson was born on February 9, 1960, and grew up on a family farm. It was while watching Apollo 11 on television from this home that she decided to become an astronaut.
University where Whitson earned her doctorate in biochemistry in 1985, a scientific foundation that underpinned her career as a researcher-astronaut at NASA.
NASA's training and mission control center where Whitson began training in 1996, served as Chief of the Astronaut Corps, and from which her missions were coordinated.
Orbital laboratory located approximately 400 km above Earth where Whitson spent a total of 665 days, commanded two missions, and completed her 10 spacewalks, setting world records.
Russian space launch facility from which Whitson lifted off aboard Soyuz capsules to reach the ISS during her second and third missions. The oldest and largest cosmodrome in the world.
