Canadian astronaut Robert Thirsk trains at the Baikonur cosmodrome in Kazakhstan on May 16, 2009. (Associated Press)

Just when most Canadians are preparing to break out the barbecue, astronaut Robert Thirsk said goodbye to fresh food, swimming pools and sunshine until November.

Thirsk is a member of a six-person crew that will live on the International Space Station for six months. On May 27, he and two other crewmates launched from Kazakhstan to join the other three already aboard the station.

This is Thirsk's second trip into space, and the first time a Canadian has participated in a long space mission.

Many people think being an astronaut is a glamorous career, but Thirsk says he's heard from his colleagues that life on the space station is anything but.

Endurance will be tested

"Living aboard a space station is not like living in a four-star hotel," Thirsk told the CBC News in a February 2008 interview. He was sequestered at NASA in preparation for his mission and was unavailable for interviews prior to the launch.

He'll sleep in a bunk the size of a telephone booth, drink water that comes from recycled sweat and urine, and eat freeze-dried food.

A major goal of the mission, dubbed Expedition 20/21 by NASA, is to test the endurance of the human body in space. Scientists hope to use the information to one day build space colonies on the moon and Mars.

Robert Thirsk, right, and other astronauts give the thumbs-up before their final preflight examination at the Russian Space Training Centre in outside Moscow on May 6, 2009. (Mikhail Metzel/Associated Press)The International Space Station is in the final stages of an 11-year construction project. Fifteen nations are partners in the orbiting laboratory. This mission will be the first time six people will live on the station for such a long time.

In addition to performing scientific experiments and repairing and maintaining the station, Thirsk will be the crew's medical officer and a robotics specialist.

One robotics experiment he'll perform will be to control a small, wheeled rover from the station. The rover, nicknamed Red, will ride around a dusty back lot near the Canadian Space Agency's headquarters in Montreal. A rover on Mars could be controlled from the space station in a similar way. (Robotics in space are often operated from Earth, but this will be the first time a robot on Earth has been controlled from space.)

Canadian contributions

Thirsk says being Canadian helped him get chosen for the space station mission. Canada's main contribution to the space station is its robotic arm, called the Canadarm 2, and NASA holds Canada's medical schools in high esteem.

But Thirsk has a lot more going for him than just citizenship. At 55, he's obtained degrees in mechanical engineering from the University of Calgary and MIT, as well as a doctorate in medicine from McGill and an MBA from MIT's Sloan School of Management.

Since beginning training for the astronaut program in 1984, Thirsk has taken part in a number of rigorous missions and simulations.

He lived under the ocean off the coast of Florida for 11 days as the crew commander in a mission simulation. He's served as the communications link between the ground and astronauts for the International Space Station. And he's already made one trip to space in 1996, when he served as a payload specialist on a space shuttle mission.

'A Canadian typically knows an awful lot about the hockey teams and the hockey players, but I was unusual in that I knew just as much about the early astronauts and cosmonauts.'—Canadian astronaut Robert Thirsk

Born in New Westminster, B.C., Thirsk says he was inspired to become an astronaut as a child by following the American space race to put a man on the moon.

"A Canadian typically knows an awful lot about the hockey teams and the hockey players, but I was unusual in that I knew just as much about the early astronauts and cosmonauts," he said in an interview with NASA.

He stumbled into his extraordinary career in a surprisingly ordinary way: By responding to a newspaper ad. When Canada started its space program, it placed ads in major newspapers saying it was looking for astronaut volunteers and listing the qualifications required.

A dream come true

Thirsk realized he was a match. "These dreams that I had of being an astronaut when I followed the careers of John Glenn and Neil Armstrong came flooding back to me," he told NASA.

"So my application was in the next day."

There has been a price associated with Thirsk's ambition. He's married with three children and says spending six months away from his family will be hard.

His wife and each of his children are having special rings designed that he will take with him on the mission, he said at a press conference aired May 7 on Russia Today TV.

He'll also be saying goodbye to bone density and muscle mass, which degrade in a manner similar to osteoporosis in the space station's low gravity environment. To combat this, he'll be taking nutritional supplements and exercising for two and a half hours a day.

But the challenge is part of what drives the crew, Thirsk told CBC News in the 2008 interview.

"It's only in those situations where you are able to realize what your own weakness and strengths are and the weaknesses and strengths of your astronaut colleagues as well, and then work as a team to meet everyone's needs."