Peggy Whitson: Record-Holding Astronaut

Peggy Whitson Talks from ISS
NASA astronaut and space station crewmember Peggy Whitson speaks with a representative of the Guinness Book of World Records on July 26, 2017. (Image credit: NASA TV)

Astronaut Peggy Whitson has spent more time in space than any other American, and that is only one of the records she holds. She retired from NASA on June 15, 2018.

Joining NASA

Peggy Annette Whitson was born Feb. 9, 1960, in Mount Ayr, Iowa. After earning her bachelor of science degree in biology and chemistry from Iowan Wesleyan College in 1981, she went on to earn her doctorate in biochemistry from Rice University in 1985. Whitson then served as a National Research Council Resident Research Associate at NASA's Johnson Space Center, and later as the supervisor for the Biochemistry Research Group at KRUG International, a medical sciences contractor at NASA-JSC. She was also an adjunct assistant professor at the University of Texas and at Rice University.

On May 6, 1989, Whitson married Clarence F. Sams in Harris, Texas. Sams, also a biochemist, had joined NASA in 1984, researching the biological effects of spaceflight at the cellular and subcellular levels.

Also in 1989, Whitson began work as a research biochemist at JSC, serving as a technical monitor of the Biochemistry Research Laboratories. In 1992, she was named the project scientist of the Shuttle-Mir program, where she served for three years. She also served as deputy division chief of the medical Sciences Division at Johnson.

Headed for space

In 1996, Whitson was selected as an astronaut candidate; she started training that August. After two years of training and evaluation, she was assigned technical duties in the Astronaut Office Operations Planning Branch and served as the lead for the Crew Test Support Team in Russia from 1998 to 1999.

On June 5, 2002, Whitson launched with the Expedition 5 crew on her first trip to the International Space Station. She was there for six months. Named the first NASA Science Officer during her stay, Whitson conducted 21 investigations in human life sciences and microgravity sciences. She returned to Earth on Dec. 7, 2002, logging 184 days, 22 hours, and 14 minutes in space.

Whitson returned to space on Oct. 10, 2008, as part of Expedition 16, this time as the first female station commander. Along with Pamela Melroy, she was one of the first pair of women to lead missions together at the same time. (Melroy led a 13-day shuttle mission.) While onboard the ISS, she oversaw the first expansion of the station's living and working space in more than six years. She returned to Earth on April 19, 2008, after 191 days, 19 hours and 8 minutes in space. At that time, she had accumulated the most time in space for any woman. She also surpassed Sunita Williams for woman with the most spacewalks during her fifth overall Extravehicular Activity (EVA); she would make one more by the end of the mission.

It would be almost a decade before she returned to space. Whitson served as the Chief of the Astronaut Corps from 2009 to 2012, the first female, nonmilitary Chief of the Astronaut Office. In this position, she was responsible for the mission preparation activities and on-orbit support of all International Space Station crews and their support personnel.

Although she enjoyed the job, she wasn't ready to say goodbye to space.

"It was actually a very satisfying job, but I did know that I still wanted to fly again — at least, I was not willing to say I didn't want to fly anymore," Whitson said in a Youtube video for the AARP. "So that's when I stepped down to get back in line [for a flight]."

NASA astronaut Peggy Whitson is pictured with an Orbital ATK Cygnus spacecraft (left) during a May 12, 2017 spacewalk outside the International Space Station. Whitson, the station's commander, and fellow NASA astronaut Jack Fischer will conduct a repair spacewalk on Tuesday, May 23. (Image credit: NASA)

Record-breaking trip to space

On Nov. 17, 2016, Whitson once again launched into space as part of Expedition 50/51. At the age of 56, she immediately became the oldest woman to go to space. [In Photos: Record-Breaking NASA Astronaut Peggy Whitson]

Although initially planned to spend only three months in space, Whitson's stay on the ISS was extended by three more months. She returned home on Sept. 2, 2017, after clocking 289 days, 5 hours and 1 minute in space. She now holds the record for the most cumulative days in space for an American, as well as the most cumulative days for a woman of any nationality.

"I haven't felt bored since I got here in November last year," Whitson said from orbit (July 26) in a video interview with a representative of the Guinness Book of World Records. "I think if you have the right attitude, you can stay in space for a long period of time, and it's actually very satisfying and enjoy[able]."

While in space, Whitson performed four additional spacewalks, bringing her total to 10. This ties her for first place with Michael Lopez-Alegria for the most spacewalks performed by NASA astronauts. She also clocked the most time spent by a woman performing EVAs.

"I feel like the reason I'm here is to do my job, and I'm going to do it to the best of my abilities," she said in the interview with Guinness.

"The records, I think, are important for NASA, to demonstrate what we're doing, how we're expanding and what we're improving on. And that continual improvement, that continual expansion of our records, is an important one for all of us at NASA, not just me

More to come?

Whitson isn't quite ready to call off her spaceflight adventures. In a media interview from orbit on April 13, 2017, she said she would like to visit other worlds.

"I would definitely like to go to the moon or Mars or some other destination," Whitson said.

"Space Station has been phenomenal but I would like to take some of the next steps. I'm not sure if I will last that long, but I'll give it my best."

Records, current and broken

Expedition 16

  • One of the first pair of women to lead missions at the same time 
  • Oct. 10, 2008: First female commander for the ISS
  • Dec. 16, 2008: Most cumulative spacewalk time for a woman during her fifth spacewalk, at 32 hours, 36 minutes over five spacewalks

Astronaut Office 

  • 2009: First female, nonmilitary Chief of the Astronaut Office

Expedition 50/51/52

  • Nov. 17, 2016: Oldest woman to go to space at the age of 56, first woman to command the International Space Station twice
  • March 30, 2017: Most spacewalking time accumulated by female astronaut
  • April 24, 2017: Most cumulative days in space for an American, and by a woman of any nationality (534 days, 2 hours, 48 minutes; when she landed, she had clocked 665 total days in space) 
  • May 23, 2017: On her 10th spacewalk, tied with Michael Lopez-Alegria for most by NASA astronauts
  • Nov. 17, 2017: With 665 days in space, Whitson holds the record for most days in space for an American astronaut and the most for a woman of any nationality. On the all-time spaceflight endurance list, she currently sits at number 8.

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Nola Taylor Tillman
Contributing Writer

Nola Taylor Tillman is a contributing writer for She loves all things space and astronomy-related, and enjoys the opportunity to learn more. She has a Bachelor’s degree in English and Astrophysics from Agnes Scott college and served as an intern at Sky & Telescope magazine. In her free time, she homeschools her four children. Follow her on Twitter at @NolaTRedd