The Shenzhou 9 and its crew of three, including China's first woman in space, linked with the Tiangong1 module just after 7am South African time.

This is the first time that China has been able to transfer its astronauts from one orbiting craft to another.

During the 13-day mission, the astronauts will work and sleep aboard Tiangong 1, a trial module that carries an exercise bike and a video-telephone.

Rendezvous and docking exercises between the two vessels are important in honing China's efforts to acquire the technological and logistical skills to run a full space laboratory that can house astronauts for long periods.

China is still far from catching up with the established space superpowers - the US and Russia.

The docking mission is the latest show of China's growing prowess in space and was staged as budget restraints and shifting priorities hold back manned US space launches.

The US will not test a new rocket to take people into space until 2017. Russia has said manned missions are no longer a priority.

Nasa has begun investing in US firms to provide commercial space flight services. It is spending about $3-billion a year on a new rocket and capsule to send astronauts to the moon, asteroids and eventually Mars.

China plans an unmanned moon landing and the deployment of a moon rover.

Sending a man to the moon is unlikely before 2020.