Three Chinese astronauts on Monday entered an orbiting module for the first time, in a move broadcast live on China's state television network and a key step towards the nation's first space station.

The astronauts, two men and a woman, passed into the Tiangong-1 ("Heavenly Palace") module a little under three hours after it docked with the Shenzhou-9 ("Divine Vessel") spacecraft.

The Shenzhou-9 took off Saturday carrying the first Chinese woman to go into space, before undergoing the third automatic docking China has ever performed, and the first for a manned mission.

The astronauts, who were shown waving to a camera as they floated inside the narrow Tiangong-1 capsule, will attempt to complete the highly technical docking procedure manually later in their 13-day mission.

The Tiangong-1 is an experimental module that is part of China's programme to build a space station by 2020.

It will only stay in orbit until 2013 and will later be replaced, but is designed to test the docking technique essential to a space station -- a delicate move the Russians and Americans successfully completed in the 1960s.

The manoeuvre is hard to master because the two vessels, placed in the same orbit and revolving around the Earth at thousands of kilometres per hour, must come together very gently to avoid destroying each other.

Reports have said the Shenzhou-9 will remain attached to the space capsule for six days before separating in preparation for the manual docking.

President Hu Jintao has said the operation would mark a "major breakthrough in the country's manned space programme", which is gearing up just as the United States scales back its manned space exploration activities.

China sees its space programme as a symbol of its global stature, growing technical expertise, and the Communist Party's success in turning around the fortunes of the once poverty-stricken nation.

The ability to dock manually is necessary in case of any problems with the automatic procedure, such as the control centre being unable to carry it out remotely from Earth.

The team -- headed by Jing Haipeng, a veteran astronaut on his third space mission -- have rehearsed the procedure more than 1,500 times in simulations.

Liu Wang, who has been in the space programme for 14 years, will be in charge of manual docking manoeuvres, while Liu Yang, China's first woman to travel to space, will conduct aerospace medical experiments and other space tests.

Their mission has been heavily trailed in China's state-run media, with much of the attention focused on Liu Yang -- at 33, the youngest of the three.

She has been hailed as a national heroine and her mission is being excitedly followed in the Chinese media and on the country's popular microblogs.

Banners have reportedly been put up at her former high school in central China's Henan province celebrating her selection as the country's first female "taikonaut", as the country dubs its space travellers.