Update June 25: China appear to have moved the station back into its original orbit, possibly as part of a test ahead of deorbiting it.
Remember when the Chinese space station Tiangong-1 re-entered Earth's atmosphere a couple of months ago? Yeah, it made a lot of headlines. But get ready, because it looks like we’ve got another.
China has a second experimental space station in orbit, called Tiangong-2. But it looks like they have lowered the orbit of it by about 90 kilometers (55 miles), from about 380 to 290 kilometers (235 to 180 miles, SpaceNews first reported, to prepare to bring it back to Earth. That’s according to orbital information from US Strategic Command.
Speaking to IFLScience, Jonathan McDowell, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics, said that China was likely trying to avoid the same fate that befell Tiangong-1. They appear to have lowered the orbit of the station on June 13. “We don't know when the next burn will be,” he added.
That station infamously made headlines when it returned to Earth uncontrolled. China had lost control of the station in 2016, with no one sure exactly where it would land. Eventually the station, weighing 8,500 kilograms (18,800 pounds), crashed into the Pacific Ocean.
Tiangong-2 was launched in September 2016, and has been by one crew of two people from October to November 2016, with no further missions there planned. China had been using it to prepare to launch a bigger station, the first module of which is expected to launch in 2020.
China has not made any announcement via its China Manned Space Engineering Office (CMSE) about de-orbiting this space station yet. So we don’t know when they might be planning to do it, or why exactly, although it does appear to be an attempt to avoid that previous tricky situation.
“In part China doesn’t want a repeat of Tiangong-1 going rogue,” Phil Clark from the Journal of the British Interplanetary Society told SpaceNews.
A lot of stuff re-enters our atmosphere, both big and small, with less fanfare than Tiangong-1 did. Tiangong-2 is almost identical in size, so when it does re-enter, it probably won’t cause too much of an issue on the ground.
Most of the pieces of a station this size would be expected to survive. Plus, the orbit of the station – which is almost identical to Tiangong-1 – takes it largely over water, so even if it was uncontrolled it would be unlikely to hit a populated area. If China is bringing it down in a controlled manner though, then you’d presume it’d be okay.
Such things don’t always go to plan, mind. And you can be pretty certain that, whatever happens, this won’t be the last you’ve heard of Tiangong-2.