BEIJING (AFP) - Three Chinese astronauts returned safely to Earth Sunday after spending six months at China's Tiangong space station with "complete success" in their mission, state media reported.

The Xinhua News Agency quoted the Chinese Manned Space Agency as saying that the team, which has been at the station since early June, landed in Dongfeng in Inner Mongolia at 8:09 pm Beijing time (12:09 GMT).

She added that doctors said the pioneers were in good health.

The Tiangong space station is the crown jewel of China's ambitious space program, which has succeeded in landing robotic probes on the surface of Mars and the Moon, and made China, which is looking to catch up with the United States and Russia, the third country to send humans to Earth's orbit.

The three Chinese astronauts of the Shenzhou-14 mission are Commander Chen Dong, China's first female astronaut Liu Yang, and her companion Cai Xuezhe, and they have been entrusted with overseeing the final stages of building the space station.

The last unit was successfully docked with the main structure of the Tiangong station last month, according to state media, in a major step ahead of the station's completion by the end of the year.

"It is an honor to witness the formation of the basic structure of our space station," said Chen, an air force pilot who became the first Chinese astronaut to stay in space for more than 200 days.

The team handed over the mission to the Shenzhou-15 crew, the first Chinese delivery in space.

China has been excluded from the International Space Station project since 2011, after the United States banned NASA from dealing with it.

It is expected that the weight of the Tiangong station, after its completion, will reach 90 tons, or a quarter of the weight of the International Space Station, so that it is similar in size to the Soviet Mir station that swam in Earth orbit from 1980 to 2001.

Tiangong, which means "heavenly palace," will remain in service for nearly a decade and host many scientific experiments conducted in near zero gravity.