Tracy Caldwell Dyson, born August 14, 1969 in Arcadia, California, is a veteran of two missions into space. She studied atmospheric chemistry at the University of California, Irvine.
Her first mission was aboard Endeavour (STS-118) as mission specialist in August 2007 to the International Space Station. She celebrated her 38th birthday during the flight.
Her second flight was aboard Soyuz TMA-18 as flight engineer in April 2010. She participated in Expeditions 23 and 24. She returned to Earth in September 2010.
