A Russian Soyuz craft launched into the morning skies over Kazakhstan on Sunday, carrying three astronauts on their way to the International Space Station, where they will quickly start preparing for a frenzy of incoming traffic.

NASA astronaut Sunita Williams, Russian cosmonaut Yury Malenchenko and Japan's Akihito Hoshide are set to travel two days before reaching their three colleagues already at the permanent space outpost.

Families and colleagues watched the launch from an observation platform in the Russian-leased cosmodrome in the dry southern steppes of this sprawling Central Asian nation.