Two Chinese astronauts have successfully returned to Earth after 30 days in space, reports CNN.

Jing Haipeng and Chen Dong have lived and worked in the Tiangong-2 space lab since October 18, the longest stay in space by Chinese astronauts.

The reentry module of the Shenzhou-11 spacecraft landed in Inner Mongolia around 2.15 p.m. Friday local time, after detaching from the space lab and heading for home Thursday.

The Tiangong-2, whose name translates as "heavenly vessel," was launched on September 15 and had unmanned until the astronauts arrived the following month.

The lab is a key part of China's space program, on which the country has spent billions of dollars, with the eventual aim of launching a Chinese space station into orbit.

China is planning to launch the permanent 20-ton space station before 2024, when the International Space Station (ISS) is retired, according to state news agency Xinhua.

"Tiangong is a precursor testbed of capabilities. Building toward the large space station has always been the culminating goal of the Shenzhou program," said Joan Johnson-Freese, a professor at the Naval War College specializing in space programs and space security.