Then the even more delicate and precise docking process began.

"If spacecraft rendezvous is like two people getting closer together and meeting each other, then spacecraft docking is like the two people joining hands," said Bai Mingsheng, vice chief designer of the space lab system of China manned space program.

The two spacecraft will fly as one for 12 days under the command of Tiangong-1. Then the two will unhook and remain 140 meters apart to await a second docking.

The two craft will then fly together for two more days, before Shenzhou 8 separates from Tiangong-1 and withdraws to a safe position 5 km away. "Its return capsule will head back to Earth in mid-November," Wu said.

"Next year, China will launch two more Shenzhou spacecraft, Shenzhou 9 and Shenzhou 10, to dock with Tiangong-1 and at least one will be manned," Wu added.

Ultimately this series of space docking tests and experiments will provide crucial experience for China's construction of a permanent manned space station.

"Although Shenzhou 8 is unmanned, we equipped the spacecraft with devices which record real images and mechanical parameters during its flight, both of which are vital to future manned missions. Tiangong-1 is also in full readiness for the entry of astronauts next year," Wu said.

Equipment for astronauts to use for physical exercises, medical monitoring and health maintenance has already been installed inside Tiangong-1.

Chen Shanguang, Director of the Astronaut Center of China, was quoted by Xinhua News Agency as saying that a crew of nine, including two women, has already been selected and is being trained in manual docking skills.

He said that the seven men are from the country's first batch of 14 astronauts, which includes Yang Liwei, China's first man in space in 2003, and Zhai Zhigang, the first to conduct an extra vehicular activity in 2008.

The two female astronauts, both air-freighter pilots before their enrollment, are from the second batch of astronauts trained between 2009 and early 2010.

"We must assess the performance of both male and female astronauts, it is important to monitor the impact of space travel on both genders, and space exploration activities would be incomplete without the participation of female astronauts," said Chen.

"Besides testing docking technology, the Shenzhou 8 will also carry out scientific experiments," Wu said.

On this mission, Chinese and German scientists will conduct 17 space life science experiments. "German scientists designed bio-incubators for the experiments, while their Chinese counterparts were in charge of the development of control equipment," Wu said.

The experiments will help promote the study of microgravity and space life science, 10 of the experiments will be controlled by China, six by Germany, and one will be a joint effort.

"It is the first time China's manned space program has conducted joint experiments in the field of space life science," Wu said.

"New knowledge obtained through space science research should be used for the common wealth of all human beings and should benefit the whole world," chief designer Zhou said.