U.S. astronaut Michael Barratt and Russian cosmonaut Gennady Padalka have practiced a manual docking procedure before next week's blastoff to the international space station.

U.S. businessman and space tourist Charles Simonyi watched Saturday as Barrett and Padalka grappled with a joystick in a computer simulation at a Soviet-era training and preparation facility in Baikonur.

Docking is an automatic procedure but manual proficiency is necessary in case of malfunctions.

The three are in quarantine before Thursday's liftoff, and have done rigorous exercise and anti-motion sickness preparations. They say they are in ideal physical condition.

In their free time they are playing backgammon, table tennis and billiards.