MOSCOW — A billionaire American space tourist in the middle of his second stay aboard the international space station will return to Earth a day later than planned due to flooding at the landing site, Russian officials said today.

The Federal Space Agency said a Soyuz capsule carrying former Microsoft executive Charles Simonyi and two other crew members is now set to land in Kazakhstan next Wednesday.

Mikhail Polukhin, the chief of Russia’s Aviation and Space Rescue Service, told The Associated Press that the landing was postponed because the original landing site near the city of Arkalyk has been affected by spring flooding.

Polukhin said the new site was moved further south to an area about 85 miles northeast of the city of Dzhezkazgan.

Simonyi, 60, will return to Earth with U.S. astronaut Mike Fincke and Russian cosmonaut Yuri Lonchakov. Simonyi, who boarded the orbital station Saturday after a two-day trip from Earth, is the world’s first two-time space tourist.

While returning from his first flight in 2007, Simonyi landed in the same area that has been chosen now, Polukhin said. “The area is well-explored and convenient,” he added.

Simonyi, who paid $35 million for his trip, may be the last private traveler the Russians allow to catch a ride to the space station. Its permanent crew is set to increase from three to six as other partners in the project — Japan, the European Space Agency and Canada — plan to send up astronauts later this year.