Expedition 51 crewmember Jack Fischer signs a commemorative book in a traditional ceremony.

At the Gagarin Museum at the Gagarin Cosmonaut Training Center in Star City, Russia, Expedition 51 crewmember Jack Fischer of NASA (front row, right) signs a commemorative book in a traditional ceremony April 3. Looking on are crewmate Fyodor Yurchikhin of the Russian Federal Space Agency (Roscosmos, front row, left) and in the back row, backup crewmembers Sergey Ryazanskiy of Roscosmos (back row, left) and Randy Bresnik of NASA (back row, right). Fischer and Yurchikhin 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. Photo: NASA/Rob Navias