Expedition 51 crewmembers Fyodor Yurchikhin during the second of two days of final qualification exams.

At the Gagarin Cosmonaut Training Center in Star City, Russia, Expedition 51 crewmembers Fyodor Yurchikhin of the Russian Federal Space Agency (Roscosmos, left) and Jack Fischer of NASA (right) field questions from reporters in front of a Soyuz spacecraft mockup March 31 during the second of two days of final qualification exams. Yurchikhin and Fischer will launch April 20 on the Soyuz MS-04 spacecraft from the Baikonur Cosmodrome in Kazakhstan for a four and a half month mission on the International Space Station. Expedition 51. Photo: Rob Navias/NASA.