Expedition 51 backup crewmembers pose for pictures during a final inspection of the Soyuz MS-04 spacecraft.

In the Integration Facility at the Baikonur Cosmodrome in Kazakhstan, Expedition 51 backup crewmembers Randy Bresnik of NASA (bottom) and Sergey Ryazanskiy of the Russian Federal Space Agency (Roscosmos, top) pose for pictures April 14 during a final inspection of the Soyuz MS-04 spacecraft. They are serving as backups to Fyodor Yurchikhin of Roscosmos and Jack Fischer of NASA, who will launch April 20 on the Soyuz MS-04 spacecraft for a four and a half month mission on the International Space Station. Credit: NASA/Gagarin Cosmonaut Training Center/Andrey Shelepin