Watch: Astronomers Detect Possible Sign of Life on a Planet 120 Light-Years AwayFour astronauts aboard the International Space Station are making an unprecedented move. NASA's Michael Fincke and Zena Cardman, as well as Japanese astronaut Kimiya Yui and Russian cosmonaut Oleg Platonov, are heading back to Earth about a month earlier than expected due to a medical issue involving one of the crew members. This will be the first-ever medical evacuation in the 25-year history of the ISS.