China's 8.5-tonne Tiangong-1 space station, originally launched in 2011, has seen its orbit decay and is now expected to hit the Earth in the next few months, according to a report in The Guardian newspaper.
According to Chinese officials who spoke to UN officials in 2016, they had lost the ability to correct the station's altitude and expected it to plummet to the ground between October 2017 and April 2018. However, Harvard University astrophysicist Jonathan McDowell told the newspaper that it is now entering the atmosphere at an even more accelerated timetable, and is likely to fall to the earth in the earlier part of that range.
''Now that [its] perigee is below 300 kilometers [186 miles] and it is in denser atmosphere, the rate of decay is getting higher,'' McDowell said. ''I expect it will come down a few months from now-late 2017 or early 2018.''
He added there remained a small chance that chunks of the station weighing up to 220 pounds (100 kilograms) could remain intact and hit the ground at high speed.
The Tiangong-1, which is very small by space station standards, can only accommodate a small crew of three taikonauts and is only meant to serve as a prototype for future generations of Chinese stations and support craft.
At present, scientists have no idea when or where the remains of the space station will land, but the chances of the fragments of lab falling on a populated area are remote, they say.
According to space archaeology expert Alice Gorman, of Flinders University, while China will be able to monitor its descent, it will not be able to control its landing.
"Contact has been lost with the spacecraft, so apart from monitoring its position the re-entry is uncontrolled," she said, www.abc.net.au reported.
Gorman said since September 2016, when China's Xinhua news agency reported that Tiangong-1 was "intact and orbiting at an average height of 370 kilometres", it has dropped 60 kilometres.