China’s mysterious space plane has returned to Earth after spending over 8 months in orbit.

The reusable spacecraft landed at the Jiuquan Satellite Launch Center in a remote section of northwest China on Friday (Sept. 6). It launched from the same site atop a Long March 2F rocket on Dec. 14, 2023, on its third mission, and spent 268 days in orbit, according to Chinese state media outlet Xinhua.

It’s unknown what exactly China’s space plane was doing on this most recent mission  — or on any other mission, for that matter. As with seen in previous missions, spacecraft trackers on the ground observed the space plane releasing a small object into orbit.