The Expedition prime and backup crewmembers pose for pictures in front of the Tsar Cannon as part of their pre-launch visit.

The Expedition 53-54 prime and backup crewmembers pose for pictures in front of the Tsar Cannon at the Kremlin in Moscow Sept. 1 as part of their traditional pre-launch visit. From left to right are prime crewmembers Joe Acaba of NASA, Alexander Misurkin of Roscosmos and Mark Vande Hei of NASA and backup crewmembers Shannon Walker of NASA, Anton Shkaplerov of Roscosmos and Scott Tingle of NASA. Misurkin, Acaba and Vande Hei will launch Sept. 13 from the Baikonur Cosmodrome in Kazakhstan Sept. 13 on the Soyuz MS-06 spacecraft for a five and a half month mission on the International Space Station. Credit: NASA/Elizabeth Weissinger