NASA astronaut Rick Mastracchio, Expedition 38/39 flight engineer, responds to a question from a journalist or social media participant during an Expedition 38/39 preflight press conference at NASA's Johnson Space Center.
JSC2013-E-078072 (28 Aug. 2013) — NASA astronaut Rick Mastracchio, Expedition 38/39 flight engineer, responds to a question from a journalist or social media participant during an Expedition 38/39 preflight press conference at NASA’s Johnson Space Center. Photo credit: NASA