Beijing: China on Tuesday successfully launched an unmanned spacecraft for its maiden docking mission, paving the way for its first space station by 2020 to rival Mir, the space lab being run by Russian and US astronauts.

The launch of unmanned spacecraft Shenzhou-8 in the early hours on Tuesday from Jiuquan Satellite Launch Center in northwest Gobi desert was successful, Commander-in-chief of China's manned space programme Chang Wanquan announced.

The spacecraft was sent into the designated orbit by Long March-2F rocket.

It is heading for rendezvous with Tiangong-1, or "the Heavenly Palace" that was put into space on September 29 for the country's first space docking, which was expected to take place in the next two days.

The move, if successful, will pave the way for China to operate a permanent space station around 2020 and make it the world's third to do so after the US and Russia. This will be the second space station after the Mir space lab launched in 2001 by Russia.

Mir is currently managed by Russian and US space programmes.

The docking of the Shenzhou-8 will take place at a height of 343 km above the Earth's surface. It will return to the Earth after two docking tryouts.

Chinese and German scientists will conduct 17 life science space experiments on the Chinese spacecraft Shenzhou-8, Wu Ping, spokeswoman for China's manned space programme, said.

To ensure the success of the mission, Chinese space engineers have made "considerable modifications" on Shenzhou-8 to previous versions of the spacecraft.

Shenzhou-8, with a length of nine metres and a maximum diameter of 2.8 metres, has a liftoff weight of 8.082 tonnes.

"More than half of the 600 or so sets of equipment have been modified, while newly designed devices account for about 15 percent of the total," Wu said.

The modifications were mainly aimed at arming the spacecraft with automatic and manual rendezvous and docking capacities, and enhancing the vehicle's performance, safety and reliability, Wu said.

"After the improvements, the spacecraft will be able to connect with the target spacecraft Tiangong-1 for 180 days," Wu said.

The unmanned spacecraft is also equipped with devices for recording real images and mechanical parameters during its flight, to test the space docking before a manned attempt.

Once China has mastered the technologies of rendezvous and docking, it will be equipped with the basic technologies and capacity required for building a space station, Zhou Jianping, chief designer of China's manned space programme said.

The mission will be followed by launches of spaceships Shenzhou-9 and -10 in 2012, which are also expected to dock with Tiangong-1.

"At least one mission of the two will be manned," Wu said.    

The crew members, including probably two female astronauts, have already been selected for the possible manual space docking mission in 2012 and are being trained for manual docking skills.

The space docking tests and experiments will provide crucial experience of China's construction of a 60-tonne permanent manned space station around 2020 when Chinese astronauts are expected to operate more research projects in space.

"It will make it possible for China to carry out space exploration of a larger scale," Zhou said.

(Agencies)