BEIJING – China launched an experimental module Thursday, marking a significant step in the country’s plan to build a space station.

The Tiangong-1 module, or “Heavenly Palace-1,” was launched into space by the carrier rocket from a remote base in China’s northwest Gansu province ahead of the country’s National Day celebration Saturday.

The unmanned module, which will be operated remotely from a center in Beijing, will serve as a space laboratory and a docking target for other spacecraft. It will remain in space about two years.

The module is expected to rendezvous and dock with Shenzhou 8, another unmanned craft that is due to launch in early November. If the mission is successful, the module will dock with two more spacecraft, Shenzhou 9 and 10. Manned missions may begin in 2012.

Joan Johnson-Freese, a space expert at the U.S. Naval War College in Newport, R.I., said China’s spaceflight technology is roughly as sophisticated as that of Gemini, NASA’s human spaceflight program in the mid-1960s.

The launch Thursday was part of the second stage in China’s three-step strategy for the development of its space program.

The first step was the development of the Shenzhou capsule program, which in 2003 made China the third country in the world to successfully launch a human being into space. The second step currently under way involves spacewalking as well as rendezvous and docking. Chinese astronaut Zhai Zhigang completed the country’s first spacewalk in 2008. A space station may be launched between 2020 and 2022.