Three Chinese astronauts floated into the orbiting Tiangong-1 yesterday afternoon following the successful docking of Shenzhou-9 with the space lab module earlier, marking the commencement of a series of science experiments inside. 

At around 5:14 pm yesterday, 46-year-old commander Jing Haipeng became the first to glide into the 8.5-ton Tiangong-1, which has been waiting for the astronauts for 263 days.

Jing, who went to space in 2008 on Shenzhou-7, was soon joined by his fellow astronauts, Liu Wang, 42, and 33-year-old Liu Yang, the first woman China has sent to space.

Their spacecraft, Shenzhou-9, successfully docked with the lab module at around 2 pm yesterday after liftoff from the base in Jiuquan, Gansu Province Saturday evening.

After a six-day stay inside Tiangong-1, the astronauts will return to the spacecraft, separate it from the lab, and attempt another manual docking, which will be the first time Chinese astronauts attempt the move.

"A manual docking, if successful, will demonstrate the country's grasp of essential space rendezvous and docking know-how," said Zhou Jianping, chief engineer of China's manned space program. "It will mean China is fully capable of transferring humans and cargo to an orbiter in space."

After a series of engine burns and orbit changes, Shenzhou-9 will have traveled some 130,000 kilometers to unite with the waiting space lab module. The rendezvous took place at an altitude of about 340 kilometers, as the spacecraft drove into the docking ring at a relative speed of 0.2 meters per second.

Liu Yang filmed the whole process with a hand-held camera. Ground control instructed her to maintain a steady angle because the initial images were a bit disorienting, as astronauts' sense of direction can be affected in a zero-gravity environment.

The automated docking was completed in less than eight minutes. "Shenzhou-9 crew members feel great!" reported astronaut Liu Wang to the Beijing Aerospace Control Center.

Tiangong-1 will be driving the now joint module and orbit the Earth at around 7.8 kilometers per second.

Soon after docking, the three astronauts sitting inside the reentry module changed from white pressure suits into blue working uniforms.

After checking the pressure was equalized between modules, they opened the door connecting the spacecraft's reentry module to the orbital module, and then the door of the orbital module, entering the docking passage.

At 5:14 pm, the astronauts opened the door to Tiangong-1. Liu Wang immediately started checking the status inside Tiangong-1 and Jing started to work on air sampling equipment, which experts explain could monitor and measure trace amounts of toxic gas in the air.

The astronauts could be seen stumbling inside the space lab, and trying hard to grab on to the straps fixed on all four walls of the capsule in order to move back and forth.

It takes some getting used to, moving around in a considerably larger room in space, commented Yang Liwei, the first Chinese astronaut in space, on China Central Television yesterday.

The astronauts now have 15 cubic meters of space to maneuver in, compared to eight cubic meters inside the spacecraft. Tiangong-1 is decorated using a two-color scheme, yellow representing the ground and white for the sky, to give the astronauts some sense of orientation in space.

The module is equipped with exercise gear and two rooms for sleeping. Astronauts will collect toxic gas for analysis and perform a series of medical tests to see the impact of weightlessness on the human body.

Xinhua contributed to this story