Photo taken on Oct 19, 2016 shows the screen at the Beijing Aerospace Control Center showing astronauts Jing Haipeng (R) and Chen Dong celebrating on the success of the automated docking between Shenzhou XI manned spacecraft and the space lab Tiangong II. [Photo/Xinhua]

The two astronauts aboard Shenzhou XI, Jing Haipeng and Chen Dong, monitored and reported on the docking operation, relaying their findings to the control center.

According to the mission schedule, once they enter the space module, the astronauts will stay there for 30 days.

Shenzhou XI, China's sixth manned spacecraft, will undertake the longest-ever space mission in the country. The two astronauts will spend a total of 33 days in space.

Sun Jun, deputy chief engineer of BACC, told Xinhua that the precision needed for the orbit prediction and automated docking calculation was much higher than previous docking missions.

China is the third country, after the United States and Russia, to complete successfully space rendezvous and docking procedures.

Tiangong-2 was sent into space on Sept 15. It is hailed as China's first space lab "in the strict sense" and a key step in building a permanent space station, which the country aims to accomplish by 2020.