Peggy Whitson’s space missions are iconic. She spent 665 days in space, more than any other woman or U.S. astronaut, and she commanded the International Space Station (ISS) twice.

Whitson retired from NASA in June after a successful career that broke records and demonstrated the incredible value that women bring to science and space. “I have hit my radiation limit,” Whitson told Business Insider. “So [I’m] not going into space with NASA anymore.”

A Farm Girl Who Became One of the Most Successful Female Astronauts

Whitson was inspired to explore space at nine years old when humans walked on the moon for the first time in 1969. “I thought, what a cool job! It really didn’t become a reality to me to become a goal until I graduated from high school, which was coincidentally the same year they picked the first set of female astronauts,” Whitson said in an interview with NASA.

After growing up on a farm in Iowa, Whitson went on to study biology. She double majored in biology and chemistry — completing college in just three years — and went on to Rice University to study biochemistry. Whitson worked as a post-doctoral fellow at the Johnson Space Center; in 1989, she was hired by NASA to be head of the Space Center’s biochemistry section.

“I’ve always said I’ve never had a real job because I’ve always done what I wanted to do, which was work at NASA,” Whitson said.

At Johnson, Whitson served in a number of scientific roles that involved joint projects between the U.S. and Russia — the Soviet Union at the time — which prepared her for her future leadership role at the ISS. However, she didn’t have instant success. According to Business Insider, Whitson applied to be an astronaut 10 times before she was finally selected in 1996. After years of training on the ground, she experienced her first space mission in 2002, where she completed 21 science investigations and became NASA’s first space station science officer.

Peggy Whitson’s Space Missions and Achievements

On each of Peggy Whitson’s space missions, she set new records and changed perceptions of gender and its representation in space. In 2008, during her second mission, she became the first female commander of the ISS, according to NASA. She continued to break glass ceilings back on Earth, where she became the first woman and first non-military person to serve as chief of the astronaut corps. From 2016 to 2017, she was back in space, yet again setting records. She became the first woman to command the ISS twice, the oldest female astronaut and the most experienced female spacewalker, rounding out her career with “10 spacewalks totaling 60 hours and 21 minutes” in space outside an aircraft, said NASA.

On one spacewalk, Whitson saw her reflection in an array of solar panels. She told Business Insider, “I could see myself in a space suit, I could see the Earth behind me in the solar arrays, and I was like, ‘holy cow, I really am an astronaut!’ Because you forget. You’re in this moment. You’re getting a job done.”

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