China’s second space station is confounding space experts -- leading them to speculate over the fate of the Tiangong-2.

An artist's impression of the Tiangong-2 space station docked with the Shenzhou spacecraft. (Picture: China Manned Space Engineering Office)

It all started when the US Joint Space Operations Center reported that the unmanned vehicle had descended almost 60 miles, prompting some to speculate that China was getting ready to deorbit the Tiangong-2 to avoid the fate of the Tiangong-1 -- which was incinerated when it re-entered the Earth’s atmosphere on April 1st.

But then on June 22nd -- 10 days after the initial drop -- the space station unexpectedly reverted to its previous orbit height of 242 miles.

The Tiangong-2 -- which means "heavenly palace" in Mandarin -- was launched in 2016 to test its ability to support a crew and refuel while in orbit, and is considered a key step forward for China’s space program.

So what’s happening?

Jonathan McDowell, an astronomer based at the Harvard-Smithsonian Center for Astrophysics, thinks China was testing some of the systems aboard the Tiangong-2 to collect data ahead of the planned 2022 launch of a bigger, permanent space station called Tianhe.

Tiangong-1 as seen by a radar operated by the Fraunhofer Institute for High Frequency Physics and Radar Techniques. (Picture: Fraunhofer FHR via EPA-EFE)

Space is shaping up as a new battleground between the world’s superpowers -- and despite being the “final frontier”, it’s not immune from Earth-bound problems.

China has been barred from the International Space Station since 2011, when US Congress passed a law banning them from dealing with the largely US-operated station.

Last week President Trump ordered the Pentagon to create a new Space Force to prevent China from gaining dominance in space, while other countries -- including Japan and India -- are also pursuing their own initiatives.

It’s not clear when China plans on decommissioning the station, but the recent activity means it still has control of the craft, unlike the Tiangong-1 -- which authorities lost control of after keeping it in orbit beyond its original retirement date.

An added benefit is that the extra fuel used will make its eventual return to Earth less explosive.