China has launched an unmanned rocket, taking the next step toward its goal of building a space station.

China's state-run news agency, Xinhua, said the Shenzhou-8 spacecraft took off from a site in the Gobi Desert Tuesday morning.

The craft will try to dock with an experimental module, called Tiangong-1, which was placed in earth's orbit in late September. The docking process is a complex operation never before attempted by Chinese space experts.

Tuesday's launch sets the stage for more Chinese space flights next year. China is planning two more docking experiments in 2012, at least one of them with astronauts on board.

Space engineer Li Jian said technicians have been conducting extensive tests over the past week to make sure the two space vehicles are ready for the docking experiment.

He said it will be important to make sure the equipment sends back reliable measurements on the accuracy of the docking maneuver.

China is the third country after the United States and Russia to conduct manned space flights, launching its first astronaut in 2003. It aims to have a working space station in place by 2020 in a move reflecting its rapid rise to great power status.