BEIJING — The orbiter-returner combination of China's Chang'e-5 probe on Dec 12 completed an orbital maneuver, preparing to leave the lunar orbit for a trajectory that returns it to the Earth, according to the China National Space Administration.

After about six days in lunar orbit, the orbiter-returner combination completed the maneuver at 9:54 am (Beijing Time), changing from a nearly circular orbit to an elliptical orbit with a perilune altitude of 200 km.

The orbiter-returner combination is scheduled to have another orbital maneuver to escape lunar gravity and enter the moon-Earth transfer orbit to return to Earth.

Chang'e-5 is one of the most complicated and challenging missions in China's aerospace history. It is also the world's first moon-sample mission in more than 40 years.

The probe, comprising an orbiter, a lander, an ascender, and a returner, was launched on Nov 24, and its lander-ascender combination touched down on the north of the Mons Rumker in Oceanus Procellarum, also known as the Ocean of Storms, on the near side of the moon on Dec 1.

The probe's returner is expected to land at the Siziwang Banner in North China's Inner Mongolia autonomous region in mid-December.