China is counting down to Tuesday's blast-off of an unmanned rocket that will largely determine whether China has mastered the technology to begin building its own space station.

Officials announced the flight plan Monday, saying it will set the stage for one or two manned space flights next year. The Shenzhou-8 spacecraft will take off from a site in the Gobi Desert at dawn, bound for a rendezvous with the Tiangong-1 space module which was placed in earth orbit in late September.

Scientists will attempt to dock the Shenzhou spacecraft with the experimental module, a complex operation never before attempted by Chinese space experts. China plans two more docking experiments next year, 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.