China's unmanned Shenzhou 8 which executed the nation's first in-space docking has departed from the prototype space lab module Tiangong and is expected to return to Earth today.

Shenzhou 8 was launched Oct. 31 on a mission to rendezvous and dock with Tiangong 1, which is also unmanned. The two vessels linked up on Nov. 2 and had been zipping around Earth together until this morning, save for a brief spell Monday (Nov. 14) when Shenzhou 8 detached for an hour, then re-docked.

The Xinhua reported that China space officials has hailed Shenzhou 8's mission as a big success, considering it a key milestone in the nation's plan to build a 66-ton space station by 2020.

"Acquisition of the space docking technology is vital to China for implementing the three-phase development strategy of its manned space program," said Wu Ping, spokeswoman for China's manned space program.

China plans to launch two more craft, called Shenzhou 9 and Shenzhou 10, toward the space lab in 2012. At least one of those missions will be manned, Chinese space agency officials have said.

The docking missions are part of China's human spaceflight plans. The nation is just the third country, after Russia and the United States, to develop spacecraft capable of flying humans to space and back.

China has launched three manned space missions, one each in 2003, 2005 and 2008.

Meanwhile, David Cyranoski of Nature magazine wrote that in July, the Chinese Academy of Sciences (CAS) in Beijing opened its National Space Science Center (NSSC) which will take charge of overall planning for the country's space science.

"China was a space country without a space science programme," says Ji Wu, the centre's director told Nature. Now that the CAS "has got government support to manage space science missions as a series", he says, "it will lead to a new era for space science in China".

Among the projects in queue are: an orbiting X-ray laboratory HXMT to be launched in 2014; the KuaFu mission which aims to reach space in 2015; and a study on the Sun's effects on space weather.