Hanneke Weitering, staff writer for Space.com, discusses the career of NASA's Peggy Whitson. The astronaut she heads back from space on September 2nd, from a mission that gives her the U.S. record for the most days spent in space, with 665. Whitson holds numerous records, including the most spacewalks by a woman. She also became the first woman to command the space station twice, and the eldest woman to travel to space at the age of 56. The big question is whether Whitson has any missions left ahead of her. If she continues, she may one day hold the world record for most days spent in space by any astronaut.