Spacecraft completes manual docking

China is the third country to independently master the space rendezvous and docking technology, after the United States and Russia.

"China has now accomplished one and a half steps in its three-step manned space program," said Qi Faren, the first chief engineer of the Shenzhou spacecraft, at a science lecture targeting young people in Beijing on Friday.

Only two more vital technologies need to be conquered before the country is able to assemble a space station by 2020, he said.

"One is a space freighter that sends fuel and cargo up but does not return to Earth. The other is the technology to recycle water, air and other necessities that can meet astronauts' needs in long-duration missions in space," he said.

Zhou Jianping, chief designer of the manned space program, said in March that China will launch the Tiangong-2 space lab in two years, and a space freighter will be launched after that to conduct a fueling experiment with the space lab.

Launched on June 11 from Northwest China's Gobi Desert, the Shenzhou X is scheduled to return to Earth on Wednesday.

On Sunday, after the manual docking between the Shenzhou X spacecraft and the Tiangong-1 module, the three astronauts entered the space module again to carry out scientific experiments.

According to earlier media reports, the 15-day mission also includes an experiment in which the Shenzhou X flies around the Tiangong-1 module, as the future assembly of a space station requires a vessel to dock with the orbiting module from more than one direction.