Peggy Whitson holds the record for the most cumulative days spent in space by a NASA astronaut. Altogether, she accumulated 665 days in space, the most for any U.S. astronaut and eighth on the all-time space endurance list at the time of her return to Earth. In addition to her cumulative spaceflight record, Whitson was also the first woman to command the space station and previously held the record for longest-ever single spaceflight made by a woman.

Selected from thousands of applicants, Whitson began her astronaut training in 1996. During her time at NASA, Whitson flew three long-duration missions to the International Space Station. Whitson, who is also a biochemist, went on to serve as NASA's chief astronaut before retiring from the agency in 2018. Originally, Whitson began her career at NASA/Johnson Space Center as a researcher in the Biomedical Operations and Research Branch. A holder of multiple academic degrees, Whitson has been honored with various NASA medals. She was named Glamour’s Woman of the Year in 2017, and included in Time magazine's 100 Most Influential People of 2018.

Following her undergraduate years, Whitson enrolled at Rice University in 1981. Located in Houston, Texas, Rice not only offered Whitson close proximity to NASA, but also awarded her a Robert A. Welch Predoctoral Fellowship. She went on to earn her Doctor of Philosophy degree in biochemistry from Rice in 1986. Following the completion of her graduate work, she continued at the university as a Robert A. Welch Postdoctoral Fellow until October 1986, when she accepted a position at Johnson Space Center in Houston, Texas.

Despite her soaring career at NASA, Whitson has always remained in the orbit of her alma mater. In 1997, while still undergoing astronaut training, she accepted a position as adjunct assistant professor at Rice University in the Maybee Laboratory for Biochemical and Genetic Engineering. To honor her many achievements—both on and off this planet—Rice awarded Whitson with the Distinguished Alumni Award in 2010. Currently, the record-breaking astronaut continues to serve the Rice community as a faculty member and occasional guest lecturer for public events on campus.