American computer software entrepreneur Charles Simonyi is reportedly paying about $25 million to fulfill his childhood dream of flying in space. He follows in the footsteps of Dennis Tito, Mark Shuttleworth, Gregory Olsen and Anousheh Ansari - all space tourists who traveled to the ISS aboard Russian rockets.

Russian cosmonaut Oleg Kotov, center, U.S. billionaire Charles Simonyi, left, and Russian cosmonaut Fyodor Yurchikhin, right, gesture after a news conference at the training center in Baikonur, Kazakhstan, 6 Apr 2007

Simonyi's trip will afford him only a few days aboard the orbiting international space station, under an agreement between Russia's Federal Space Agency and the Virginia-based firm Space Adventures. But he says he has big plans to perform a series of experiments, including measuring radiation levels and studying biological organisms inside the space station. In training for the mission at Star City outside Moscow since late last year, Simonyi says the hardest part has been spinning in a high-speed rotating chair to help train against dizziness in space.

Simonyi travels to the ISS with Commander Fyodor Yurchikhin and flight engineer Oleg Kotov of Russia's Federal Space Agency. In brief comments to reporters at the launch pad Friday, Kotov promised his American colleague a smooth first flight.

Kotov says the crew decided to name their expedition after a polar star, which he says is one of the most stable, predictable things in space.

Before returning to Earth with the station's current crew (Russian Cosmonaut Mikhail Tyurin and American astronaut Miguel Lopez-Alegria), Simonyi plans to treat his colleagues to a gourmet dinner. The meal of roasted quail, duck breast, and rice pudding is planned for April 12, when Russia celebrates Cosmonauts Day.