Robert Thirsk of the Canadian Space Agency (back row, R) answers a question during a crew news conference with the International Space Station's first six-member crew, Expedition 20, in this image from NASA TV June 1. The crew members are (L-R) Koichi Wakata, Japan Aerospace Exploration Agency, Frank De Winne, European Space Agency, ISS Commander Gennady Padalka and Roman Romanenko of the Russian Federal Space Agency, Mike Barratt, and Thirsk. NASA TV/REUTERS/FILE

NASA's new breed of astronaut

The space station, now fully staffed, demands diplomats, not jet jockeys.

Some 48 years after the first humans rocketed into space, the International Space Station – now, finally, fully staffed – is redefining the "right stuff" astronauts need to succeed in space.

Yes, some rocket riders still have a military background and a yen to live life on the edge. And it is true that donning a spacesuit, leaving the air lock, and spending six hours floating in space as you fix your orbiting home still does require a cool head.

But now that the International Space Station is hosting its full, six-member crew, the derring-do of jet jockeys is less in demand than comfort with other cultures – like someone who knows where and when to shake a Russian cosmonaut's hand.

Space station astronauts will spend four to six months of their lives in a set of high-tech tubes no bigger than a 747 passenger jet, sleeping in a bedroom the size of a phone booth, and staring at the same faces every morning. Escaping out the front door for a brief walk around the neighborhood is not an option.

This makes the process of choosing a space station astronaut more than science – it approaches diplomacy, with selectors attempting to build an orbiting family from a potpourri of astronauts from different cultures.

The task starts with selecting the appropriate people as new astronauts, says Duane Ross, who heads the astronaut selection office at the National Aeronautics and Space Administration's Johnson Space Center in Houston. Scientific and engineering know-how are a must, of course. But so are inventiveness, patience, and humility.

"You have to be able to keep your ego in check," he cautions. "You can fake anything" for a week or two, just to get through a short mission, he says. But you can't fake being a team player for four months.

Also crucial is how well candidates think and act on their feet when a lot of activity is going on around them – or in the galley. The ability to improvise is a trait that uncovers secrets that formal training manuals don't cover: Like the incredible versatility of tortillas, or the importance of duct tape in gourmet cooking – seemingly mundane innovations that make life on orbit more enjoyable.

More candidates are signing up to try their hand. In 2007, NASA hung out the help-wanted sign for a new class of astronauts. The agency received slightly more than 3,500 applications. It's expected to announce the class of 2009 soon, adding 15 to 20 newcomers to its corps of some 90 astronauts. Last month the European Space Agency (ESA) tapped six new astronauts from 8,400 applications, bringing its list of active astronauts to 14. Canada and Japan have also added astronauts recently.

The most promising and adaptable candidates become apparent during two years of basic training, which includes two-week sessions of outdoor leadership training and shorter stints in the field during survival training. By the end, the new crop of astronauts can decide if they want to aim for the shuttle or the space station.

Some people – like astronauts with children – simply don't have the time to spend six months circling Earth.

But other factors come into play as well: such as whether the crew members will drive one another crazy.

"Clearly, as people, we get along with some people better than others," says Sandra Magnus, who returned to Earth March 28 after spending 4-1/2 months on the space station. "You certainly take that into account for a long-duration mission. You don't want to put people together who might not get along as well as you might like."