American Astranout Edward Lu, Russia's Yuri Malenchenko and Spain's Pedro Duque, have touched down safely in Kazakhstan.

They had a trouble-free flight from the International Space Station only to find themselves stranded back on earth. But as the three were being transported away by helicopter bad weather set in and they were forced to return, where they remained stranded for hours. Lu and Malenchenko, who have spent six months at the ISS, have been replaced by British born American astronaut Michael Foale and Russian Alexander Kaleri. Pedro Duque stayed in space for just one week where he completed a number of experiments. It comes amid concerns over the safety of the ISS project, particularly the platform's air cleaning system. Astronauts have reportedly complained of headaches and dizziness. NASA depends on Russia to keep the ISS programme going following the US Space Shuttle Columbia disaster which killed all seven crew on board. Meanwhile, Malenchenko was due to be reunited with his wife, who he married in the first ever space wedding.