The Manned Space Agency did not give a specific time for when it expects Tiangong-1 to hit Earth.
China said its re-entry would occur in late 2017 but that process was delayed, leading some experts to suggest the space laboratory is out of control.
The European Space Agency said: “One of the main reasons why it is so difficult to make accurate reentry predictions, even if just a few days in advance of an expected reentry, materialised during Thursday this week.
“A high-speed stream of particles from the Sun, which was expected to reach Earth and influence our planet’s geomagnetic field, did, in fact, not have any effect, and calmer space weather around Earth and its atmosphere is now expected in the coming days.
“This means that the density of the upper atmosphere, through which Tiangong-1 is moving, did not increase as predicted (which would have dragged the spacecraft down sooner) and hence the ESA Space Debris Office has adjusted the predicted decay rate.”
South Korea’s National Space Situational Awareness Organization said on its website on Sunday that the station is expected to re-enter the atmosphere sometime between 5:12am and 1:12pm Seoul time (2012 GMT to 0412 GMT) on Monday.
The 10.4-metre-long (34.1-foot) Tiangong-1, or “Heavenly Palace 1”, was launched in 2011 to carry out docking and orbit experiments as part of China’s space program, which aims to place a permanent station in orbit by 2023.
The Spacelab was originally planned to be decommissioned in 2013 but its mission was extended.
China’s Tiangong-1 stopped working in March 2016, three years after it was last occupied.
You can watch the Chinese space station online through a robotically controlled telescope at The Virtual Telescope Project.
The telescope started live coverage on Wednesday, March 28 at 12pm GMT and the webcast will feature live views of the space station in partnership with the Tenagra Observatories in Arizona as it plummets toward Earth.
The Virtual Telescope Project said: “The Tiangong-1 Chinese Space Station is reentering our atmosphere soon.
“Next 28 March, the Virtual Telescope Project and Tenagra Observatories offer you the unique chance to see it during one of its very last passage across the skies.
“You can join us online, via the internet, from the comfort of your own home.
“The Virtual Telescope Project and Tenagra Observatories, on behalf of their partnership, offer you the opportunity to see the Tiangong 1 station during one of its final passes across the stars.”
The team managed to capture an exceptional image of the space station re-entering Earth’s atmosphere as the lab was at an altitude of around 220km on March 28 – about half the altitude of the International Space Station (ISS) – and travelling at a speed of around 28,000 km/hour.
Stargazers hoping to see the Chinese space station this weekend can also check Aerospace Corporation, a non-profit research organisation in California.
The company has set up a dashboard – ‘Where is Tiangong-1 now?’ – which monitors the altitude, re-entry time and features a digital view of the space lab.