Fincke told a news conference at Star City, the cosmonaut training center near Moscow, that he would go back "as from tomorrow" if he could.

"I really want to go back," he said. "If I could go back with Gennadi, I would be ready to leave as from tomorrow."

Fincke and Russian cosmonaut Gennadi Padalka spent six months aboard the International Space Station. They landed in Kazakhstan Sunday along with Yuri Shargin, who had spent eight days on the station after arriving Oct. 16 with its new two-man crew, Salizhan Sharipov and US astronaut Leroy Chiao. They also were scheduled to remain in space for six months.

"Not everything in space is simple," Padalka said, in response to a question about the decision of the US National Aeronautics and Space Administration to rely more on robots for space exploration. "We have a flexibility that the machines do not have," he added.

He expressed skepticism over NASA plans to repair the Hubble Space Telescope using only robots.

Russian spacecraft have been the only means of getting to the space station and back since the United States grounded its shuttle fleet following the loss of the Columbia, which burned up on re-entry in February 2003, killing all seven astronauts aboard.

Sharipov and Leroy will have the task of keeping the aging space station, which has been in orbit since 1998, in working order. The pair was also expected to make two space walks to continue making preparations for the first arrival of a European resupply vessel within the next few months.

They were to conduct 41 scientific, medical, biological and technical experiments, including one focusing on research for a vaccination against the virus that causes AIDS, space officials said.

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