Tags: Astronaut.
Tracy Caldwell Dyson (born Tracy Ellen Caldwell August 14 1969) is an American chemist and NASA astronaut. Caldwell Dyson was a Mission Specialist on Space Shuttle Endeavour flight STS-118 in August 2007. She was part of the Expedition 24 crew on the International Space Station between April 4 2010 and September 25 2010. She has completed three spacewalks logging more than 22 hrs of EVA including work to replace a malfunctioning coolant pump.
