AirshowInside the Kremlin the Expedition 55 prime and backup crewmembers pose for pictures in front of the Tsar Cannon Feb. 22.

AirshowInside the Kremlin at Red Square in Moscow, the Expedition 55 prime and backup crewmembers pose for pictures in front of the Tsar Cannon Feb. 22 as part of pre-launch activities. From left to right are prime crewmembers Ricky Arnold of NASA, Oleg Artemyev of Roscosmos and Drew Feustel of NASA and backup crewmembers Nick Hague of NASA and Alexey Ovchinin of Roscosmos. Feustel, Arnold and Artemyev will launch March 21 on the Soyuz MS-08 spacecraft from the Baikonur Cosmodrome in Kazakhstan for a five-month mission on the International Space Station...Gagarin Cosmonaut Training Center/Andrey Shelepin and Irina Spektor .