After nine months in orbit, China’s mysterious spacecraft has landed for the second time, making the country one of the few organizations to successfully launch and recover a reusable spacecraft.

“The complete success of this experiment marks a major breakthrough in our country’s research for reusable spacecraft technology,” China’s state-run Xinhua news agency said earlier this month.

However, the Chinese government has released little additional information about the ship; Details of its design, capabilities and performance remain unclear.

Experts believe that the Chinese plane is probably similar to the American spaceplane Boeing X-37B, which took off in 2010. Kevin Pollpeter, a research associate at the Center for Marine Analysis, told Nature.com that the discovery of the X-37B has raised concerns among the Chinese government about the ship’s military potential. This may have prompted the country to begin developing its own version of the space program, which is closely linked to its military, Pollpeter said.

Like the X-37B, the Chinese vehicle looks relatively small and unmanned. It will likely fly for the first time in September 2020, making a short two-day flight into orbit before returning to Earth. According to a report by the Washington DC-based Center for Strategic and International Studies (CSIS), its final mission began in August 2022, when it took off from the Jiuquan Satellite Launch Center in northern China on a Long March 2F rocket. The exact purpose of the mission remains unclear.

The spacecraft launched the “object” into orbit in October, according to the CSIS report. The object apparently disappeared in January, but suddenly reappeared on satellite tracking radar in March. Experts believe this could indicate that the aircraft has some sort of satellite ejection capability, such as a robotic arm.

“The Chinese have done a lot of work with robotic arms in other contexts, like the Chinese space station,” Jonathan McDowell, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics, told Nature.

If so, the main purpose of the aircraft may be to repair damaged satellites or remove debris from orbit. However, this does not exclude military possibilities for neither Chinese aircraft nor the X-37B. However, until more details emerge, the best we can do is speculate.