Researchers blame excessive sterilization for the infectious diseases astronauts bring back to Earth. A trip to space is not always as pleasant an experience as portrayed by Jesús Calleja. Not even as described by most astronauts who have ventured beyond the Kármán line.

The four newcomers — representing the U.S., Japan and Russia — will spend the next few days learning the station's ins and outs from Butch Wilmore and Suni Williams.