What did China’s secretive Shenlong spacecraft release 600km above Earth?

Jonathan McDowell, an astronomer and space activity tracker at the Harvard-Smithsonian Centre for Astrophysics, noted that since its release, the space plane Shenlong has not made any significant manoeuvres. He suggested that it may simply be an inert piece of hardware. Similarly, amateur astronomer Scott Tilley, who has previously helped Nasa find lost satellites, confirmed that neither the object nor the plane had emitted any new signals since its release.

The third flight of Shenlong took off from the Jiuquan Satellite Launch Centre in the Gobi Desert on December 14, 2023. Unlike the US military space plane X-37B, not much information has been released about Shenlong’s size or capabilities. The maiden flight of Shenlong in 2020 lasted just two days, while its second mission in August 2022 lasted nine months. During this mission, a subsatellite was reportedly ejected and recaptured multiple times to test related technologies.

After the third launch of Shenlong in December, space activity trackers suggested that at least five objects were released into low-Earth orbit, two of which emitted radio signals similar to the plane’s signals. However, it was determined that these objects were likely debris from the Long March rocket that carried Shenlong to its initial orbit. Despite the lack of information about the current mission, it is known that the space plane raised its orbit from around 300km to 600km in late January and remains at that altitude.

Chinese space authorities have not disclosed details of Shenlong’s latest mission or its return date. A brief report released by state media after the launch mentioned that the space plane would operate in orbit for a period before returning to its intended landing site in China. The report also indicated that the mission would focus on reusable technology verification and space science experiments to support the peaceful use of space.