Tracy Caldwell Dyson

Tracy Caldwell Dyson is an American chemist and NASA astronaut. Born in Arcadia, California, she studied chemistry at California State University, Fullerton and earned her doctorate at the University of California, Davis, before a postdoctoral fellowship in atmospheric chemistry at the University of California, Irvine. NASA selected her in June 1998. She flew as a mission specialist on Space Shuttle Endeavour on STS-118 in August 2007, then lived aboard the International Space Station for Expeditions 23 and 24 in 2010 and again for Expeditions 70 and 71 in 2024. Across her flights she has completed four spacewalks totalling nearly 24 hours of extravehicular activity. Between flights she worked in Mission Control as a spacecraft communicator and hosted the NASA TV series StationLife.