Expedition 51 backup crewmembers pose for pictures at the statue of Yuri Gagarin during traditional pre-launch ceremonies.

In Baikonur, Kazakhstan, Expedition 51 backup crewmembers Sergey Ryazanskiy of the Russian Federal Space Agency (Roscosmos, left) and Randy Bresnik of NASA (right) pose for pictures at the statue of Yuri Gagarin, the first human to fly in space, during traditional pre-launch ceremonies April 7. 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 from the Baikonur Cosmodrome for a four and a half month mission on the International Space Station. NASA/Victor Zelentsov