The world's third space tourist Gregory Olsen is ready for his flight to the International Space Station (ISS) aboard a Russian vehicle, a space official said Friday.

"Gregory has fully mastered the flight training program developed for him and is ready for flight to the ISS," Valery Korzun, deputy head of the Cosmonauts' Training Center, told the Itar-Tass news agency.

Olsen will ride aloft aboard a Russian Soyuz spaceship on Oct. 1 for a brief stay on the orbiting space lab with the station's 12th crew -- Russian cosmonaut Valery Tokarev and NASA astronaut William MacArthur.

"Olsen's command of Russian leaves much to be desired," Korzun said, adding MacArthur and Tokarev, both of whom speak English, will help Olsen communicate with the Mission Control if necessary.

Last year, MacArthur and Olsen suspended training for their flight due to health problems, but medical experts have given the green light for flying after both men underwent medical treatment, Korzun said.

MacArthur and Tokarev are "well prepared for the flight," Korzun said.

MacArthur, who is to serve as commander on the 12th crew, have had three shuttle flights and Tokarev, who is assigned as flight engineer, flew on shuttle Discovery in 1999 to the ISS, according to NASA's web site.

Russian cosmonaut Sergei Krikalev and US astronaut John Phillips have been working on the station since mid-April and are due to be replaced by MacArthur and Tokarev after a six-month mission.

Before Olsen, American Dennis Tito and South African Mark Shuttleworth had spent a few days on the ISS in 2001 and 2002 respectively after paying 20 million US dollars apiece for the tour.