At the age of 57, Peggy Whitson became the oldest woman to do what?

Peggy Annette Whitson (born February 9, 1960) is an American biochemistry researcher, retired NASA astronaut, and former NASA Chief Astronaut. Her first space mission was in 2002, with an extended stay aboard the International Space Station as a member of Expedition 5. Her second mission launched October 10, 2007, as the first female commander of the ISS with Expedition 16. She was on her third long-duration space flight and was the commander of the International Space Station for Expedition 51, before handing over command to Fyodor Yurchikhin on June 1, 2017.

The flight of Space Shuttle mission STS-120, commanded by astronaut Pam Melroy, was the first time that two female mission commanders have been in orbit at the same time. After completion of her eighth EVA in March 2017, Whitson now holds the records for the oldest woman spacewalker, and the record for total spacewalks by a woman, which was broken by herself again after a ninth and tenth EVA in May 2017, surpassing Sunita Williams, who has completed 7. Whitson's cumulative EVA time is 60 hours, 21 minutes, which places her in 4th place for total EVA time. She is also the oldest female astronaut ever in space, at age 57.