MOSCOW, May 5 (RIA Novosti) - An American woman may become the first female space tourist after being chosen as backup to a Japanese man expected to blast off this fall, Russia's space agency said Friday.

Anousheh Ansari, an entrepreneur of Iranian origin, will be trained as a reserve to Japan's Daisuke Enomoto, who is slated become the world's fourth space tourist when he flies to the International Space Station this fall on board a Soyuz carrier rocket.

"A contract has been signed with Ansari, and she is undergoing training as a backup to the Japanese unprofessional member of the space crew, Daisuke Enomoto," the agency said said.

The first man to travel to the world's sole civilian orbital station in 2001 was Dennis Tito, an American millionaire of Italian extraction. South African Mark Shuttleworth and American multimillionaire Gregory Olsen were the second and third ISS tourists. All of them paid $20 million for a week at the space station.