Astronauts are living in a tin box in Antarctica, living in that isolated environment to see if they can survive a trip to Mars.  If something goes wrong, no help is coming.  The nearest human being to the Concordia research station is 400 miles away.

Editor Keith Cowing of says similar exercises have been done in the past, but you always knew at the end of the day you were going to get in your car and go home.  It’s different now.

“You know that, in the back of your mind,” Cowing says, “but if you're in the middle of a polar desert, you're being stressed by that environment, and how you react is going to show how you might react to a similar situation on Mars.”

A trip to Mars would take two years, possibly as many as three.  It's important for scientists to find out whether a man or woman can deal with the stress of isolation for that long.  They also have to be able to fix things.

“How do you select people who are one part Captain Kirk, one part Spock and one part Scotty?  I mean,” he says, “that's what you're really looking for.”