A Soyuz TMA-11 spacecraft, piggybacked on a Soyuz FG rocket, is to blast off at 5:22 p.m. Moscow time (1:22 p.m. GMT) from the Baikonur space station in Kazakhstan.
The crew members, Russian cosmonaut Yuri Malenchenko, NASA astronaut Peggy Whitson, and Malaysia's Sheikh Muszaphar Shukor, are now on a coach to the launch pad, accompanied by two Russian Orthodox priests, in line with tradition.
Shukor will spend 10 days at the ISS, and return to Earth in late October with the Russian members of the previous expedition - Fyodor Yurchikhin and Oleg Kotov.
Malenchenko and Whitson will be joined later at the ISS by new Flight Engineer Daniel Tani, arriving with the Discovery STS-120 mission, which is scheduled for launch on October 20.
Whitson is set to become the first female commander of an ISS expedition. She will spend around six months in space.
Members of the expedition will carry out 48 research experiments, including a study of human cardiovascular activity and sleep functions, as well as growth and development of plants in the absence of gravity, earth remote sensing, and a series of biotechnological experiments.
