Canadian astronaut Robert Thirsk says everything about his upcoming record-breaking six-month space mission will be "fascinating," except perhaps cleaning the toilets on the International Space Station.

When an international team of astronauts blasts off from Kazakhstan at the end of May, Thirsk will become the first Canadian to live and work onboard the International Space Station.

His six-month stay will also be the longest mission in the history of Canada's Human Space Program.

And while this is his second trip to space, Thirsk said the experience will be just as exciting as the first time.

"On my first flight, everything that I did -- no matter whether it was operating the shuttle or operating an experiment or brushing my teeth in the morning -- everything is fascinating," Thirsk said Wednesday morning on Canada AM. "Maybe toilet duty might be something that we need to take our turn at, but everything is going to be fascinating."

Thirsk will join two Americans, two Russians and one European on the mission, which calls for an intense schedule of experiments and maintenance tasks.

For his part, Thirsk will serve as the team's medical officer. He will also be in charge of all robotics on the space station, which will call for him to use the Canadarm 2 to attach a Japanese-made cargo vehicle to the station.

He will also conduct a series of experiments to examine the effects of a long-term stay in a zero-gravity environment on the human body. His findings will help future astronauts prepare for the rigours of space travel, he said.

To prepare for the mission, Thirsk has spent more than two years travelling the world, learning how the space station works, studying Russian and preparing for the experiments he will conduct.

Thirsk is training for the mission as concerns over the potential hazards of so-called space junk are on the rise.

On Feb. 10, a Russian communications spacecraft collided with a U.S.-based satellite about 800 kilometres over Siberia. The accident produced space junk that could orbit the earth and threaten other satellites for 10,000 years.

Thirsk said that there is little anyone can do to prevent collisions in space. But the accident speaks to the hazards of human travel into space, and also puts astronauts at risk, he said.

"Before the launch of Sputnik, near-earth space was pristine," he said, referring to the world's first orbiting satellite. "It seems that wherever human beings go, that environmental problems follow as well. Now it's a cluttered environment."

With files from The Canadian Press