Three Chinese astronauts have returned to Earth after completing a six-month mission aboard China"s space station. They left for space on 5 June to oversee the final construction stage of the Tiangong space station, which was completed in November. The crew touched down on board the Shenzhou-14 spacecraft on Sunday in China"s autonomous region of Inner Mongolia. China"s space agency declared the mission a "complete success". Commander Chen Dong and teammates Liu Yang and Cai Xuzhe said they were feeling well after landing, in audio aired by state broadcaster CCTV. Staff at the landing site carried the crew out of the exit capsule, which landed shortly after 20:00 local time, about nine hours after undocking from the space station. Ms Yang, China"s first female astronaut, said she had an unforgettable memory in the space station and "is excited to return to the motherland," Xinhua state news agency reported. While in space, the three astronauts oversaw the arrival of the second and third modules for Tiangong and carried out three spacewalks to check and test the new facilities. A new crew of three Chinese astronauts arrived at the space station to make its first in-orbit crew handover on Wednesday. The new crew lifted off in the Shenzhou-15 spacecraft from the Jiuquan Satellite Launch Centre in the Gobi Desert in north-west China. They will live on the station for six months. It will be the second permanently inhabited space outpost, after the Nasa-led International Space Station from which China was excluded in 2011. It is the last of 11 missions required to assemble the station that is expected to operate for around a decade and run experiments in near-zero gravity. The new crew will focus on installing equipment and facilities around the space station, a spokesperson for the China Manned Space Administration said. China is only the third country in history to have put both astronauts into space and to build a space station, after the Soviet Union and the US. Tiangong space station, or "Heavenly Palace", is China"s new permanent space station. The country has previously launched two temporary trial space stations, named as Tiangong-1 and Tiangong-2. Over the next decade of the Tiangong"s operation, it is expected China will launch two crewed missions to the station each year. China has opened the selection process for astronauts for future missions to applicants from the "special administrative regions" of Macau and Hong Kong, who have previously been excluded. China put its first satellite into orbit in 1970 - as it went through massive disruptions caused by the Cultural Revolution. In the past 10 years, China has launched more than 200 rockets. It has already sent an unmanned mission to the Moon, called Chang"e 5, to collect and return rock samples. It planted a Chinese flag on the lunar surface - which was deliberately bigger than previous US flags. — BBC