It's also been out of control for two years - a fact China only acknowledged publicly last May when it confirmed it had lost contact with Tiangong-1 and could no longer control its behaviour.
Only one person - Lottie Williams of Tulsa, Oklahoma - is known to have been hit by space debris falling to Earth.
China's 8.5-ton space station will come crashing down to Earth from Saturday onwards, the country's space authorities said, although they cannot confirm where it is likely to hit.
It was launched as unmanned, and in 2012 and 2013, two Chinese woman astronauts paid visit to the space station.
But there are concerns the bus-sized spacecraft is out of control.
Their space development plans lead to their first space station, Tiangong-1, in 2011.
First of all, the space station should mostly burn up harmlessly in Earth's atmosphere, but even if parts of the station do make it all the way to the planet's surface, the likelihood that they would land in a populated area is exceedingly small.
Having a roughly 5-day window to watch means that the space station could really fall anywhere, but even as the window narrows, it is still going to be quite hard to know where Tiangong-1 is going to come down. "It's more likely than not that this thing will reenter over an unpopulated area and it may be that no on ever sees it", Abraham said.
The European Space Agency (ESA) has estimated the re-entry timeline between March 30 and April 2, and expected to crash somewhere between 43-degrees north and 43-degrees south latitudes.
China has recently put the space station into "sleep mode" ahead of it de-orbitization and its replacement with a new model.
Tiangong-1 weighed 8.5 tonnes (around 8,5000 kg) on take off, but with fuel consumption has probably shed at least one tonne.
He said the debris will fall in parts and it is unlikely that anyone will be injured by its fragments.
Nevertheless, Chinese scientists do not know where and when Tiangong-1 will crash, describing its time-frame for re-entry as "highly variable".
Don't worry. According to space debris experts, the chances that you personally will be hit by of a chunk of space metal are essentially zero - less than one in a trillion.