LONGUEUIL, Que. - The world's first space clown says he's perfected a new stunt on the International Space Station: smashing his head against the ceiling.

Cirque du soleil founder Guy Laliberte was asked, during a press conference Tuesday, what tricks he'd performed since blasting off last week.

Laliberte responded that he was struggling to adjust to weightlessness in the absence of gravity -- but he promised to get better.

"The best stunt I pulled is hitting my head three times in the same day," the circus impresario quipped.

The billionaire is Canada's first space tourist, after plunking down $35 million for a two-week mission to the space station.

Laliberte will organize an international event Friday where artists in 14 cities will perform shows to raise awareness about water conservation.

He will host the spectacle from the space station, and be joined by performers like U2's Bono, Shakira, and Peter Gabriel, and also by former U.S. vice-president Al Gore.

The Cirque boss was asked whether the trip was worth $35 million and he replied without hesitation: "It's worth every penny and more."

He said not only was the trip a fulfillment of a personal dream, but also the chance to raise awareness about an important social cause.

Laliberte said he found himself grinning from ear to ear because of the joy of the experience, and he said he would gladly spend more time in space. However, he quipped that six months was probably too much for him to handle.

That was a nod to his Canadian compatriot Bob Thirsk, a professional astronaut who's currently on the space station for a six-month mission there.

Laliberte was joined by a group of astronauts for a press conference where they fielded questions from journalists on different continents, including some at NASA headquarters, in Europe, and at the Canadian Space Agency in Longueuil, Que.

Other astronauts, when asked how they felt about sharing the station with a tourist, applauded Laliberte's water campaign, saluted his sense of enthusiasm, and expressed hope that more people could get to enjoy space tourism.