Cooperation between nations comes easily at zero gravity — but soccer is a different matter, Brazil's first man in space said Tuesday after a nine-day visit to the international space station.

"The first thing that is interesting is that is that when people from different countries, with different outlooks and different cultures see the same problems and decide to solve them in different ways," their cooperation can bring "solutions for all mankind," Marcos Pontes, who returned to Earth on Sunday along with Russian Valery Tokarev and American Bill McArthur, said at a joint news conference.

Pontes, who carried a Brazilian flag and soccer jersey to the space station in the hope that it would bring his national team victory in this summer's World Cup, said he also took along a soccer ball — but found the most popular sport on Earth a daunting challenge hundreds of miles above the planet.

"I took a football with me to space, but I did not manage to play there because the ball was simply floating there and it turned out to be too complicated," he said with a smile.

The Russian capsule carrying Pontes, McArthur and Tokarev — both of whom had spent six months on the space station — touched down Sunday in Kazakhstan after what mission control officials called a flawless flight.

McArthur said the experience of station crews would be useful for future interplanetary manned missions.

"I think we've demonstrated the capability to perform the type of very complex tasks that are going to be required of a crew between the Earth and Mars when they know they cannot rely on a a supply ship from Earth and they can't wait for the next crew to come up," he told the news conference at Star City, the cosmonaut training center outside Moscow.

Pontes had arrived at the station on April 1 with its new crew members, Russian commander Pavel Vinogradov and U.S. flight engineer Jeff Williams, who are also to spend six months in orbit.

Pontes, a Brazilian air force lieutenant colonel, trained in the United States and had been scheduled to fly to the station aboard a U.S. shuttle — plans that were scrapped after the February 2003 Columbia explosion.

The U.S. space program has depended on the Russians for cargo and astronaut delivery since the Columbia disaster grounded the shuttle fleet.