According to a revised schedule, U.S. astronaut Michael Lopez-Alegria and Russian cosmonaut Mikhail Tyurin of the Expedition 14 crew, who began working at the world's sole orbital station on September 20, will return to Earth in April instead of March.
On their return journey, they will be joined by the fifth space tourist, Hungarian-born American software billionaire Charles Simonyi, expected to arrive at the ISS with the 15th crew.
"The idea is to sensibly time the crew's landing in Kazakhstan," the source said. "All spring landings of [ISS] crews are now to be shifted from March to April, as the Kazakh steppe is often hit by severe flooding in early spring."
The flooding makes it "extremely hard to find a dry place for a capsule with astronauts to land upon, using ballistic calculations on the ground. And landing on a flooded steppe may be quite dangerous," he said.
European Space Agency astronaut Thomas Reiter of Germany, who has been on board the station since July, will work as part of the Expedition 14 crew until December, to then hand over to Astronaut Sunita Williams.