NASA’s record-breaking astronaut, Peggy Whitson, retired today less than a year after returning from her last and longest spaceflight. She’s spent more time off the planet than any other American: 665 days over three space station missions. She’s also the world’s most experienced female spacewalker, with 10 under her spacesuit belt. Whitson was the first woman to command the International Space Station, holding the position twice, and the oldest woman […]