Tiangong II Space Lab Returning to Earth Tonight

A simulator displays the successful docking of Tiangong II and the Shenzhou XI manned spacecraft on Oct 19, 2016. [Photo by Wang Juan/For China Daily]

China's Tiangong II space lab will make a controlled fall tonight, back into the Earth's atmosphere, according to the China Manned Space Agency.

It said in a news release at 5:35 pm that the reentry would take place at a "proper time" tonight.

It noted that Tiangong II was traveling in an elliptical orbit with a perigee (closest point to the Earth) of about 190 kilometers and an apogee (farthest distance from the Earth) of about 370 kilometers by 5:30 pm and added that the spacecraft was in a stable condition at that time.

The first orbital maneuver for the reentry operation took place on Thursday night, according to the release.

During the reentry process, most of the spacecraft will burn up, with a small amount of debris expected to fall in a designated secure area in the South Pacific Ocean, the agency previously said.

Tiangong II was put into orbit in September 2016 atop a Long March 2F carrier rocket from the Jiuquan Satellite Launch Center in the Gobi Desert. The space lab is 10.4 meters high, 3.35 meters in diameter and weighs 8.6 metric tons.

After having spent more than 1,000 days in orbit, Tiangong II outlived its two-year designed lifespan. During its orbital stay, the spacecraft carried out four dockings with the Shenzhou XI manned spacecraft and Tianzhou 1 cargo spaceship, enabling China to verify a series of key technologies such as mid-term life-support and in-orbit refueling.