 Marshburn took part in three spacewalks during the mission.In May 2010, Marshburn served as an aquanaut during the mission aboard the Aquarius underwater laboratory, living and working underwater for fourteen days.Marshburn served as a Flight Engineer on Expedition 34/35 to the International Space Station, launching aboard Soyuz TMA-07M on December 19, 2012, from the Baikonur Cosmodrome in Kazakhstan, along with crew members Chris Hadfield of the Canadian Space Agency and Russian cosmonaut Roman Romanenko.