Updated | An out-of-control spacecraft will come crashing down to Earth sometime in January or February 2018, a new calculation predicts.
China announced it had lost control of the Tiangong-1 space station in September 2016 and initially thought the spacecraft would fall back to Earth in “late 2017.” Since then, refined estimates have put the date of re-entry at some point between December 2017 and March 2018.
Now, The Aerospace Corporation, a California-based nonprofit that provides assistance to the government’s national security space programs, has announced that the date of re-entry will be late January or February of next year. The corporation made this prediction using data up through September 13, 2017.
Andrew Abraham, senior member of the technical staff for The Aerospace Corporation, tells Newsweek: “[We] receive orbital data from the Joint Space Operations Center (JSpOC) on a daily basis. We have been monitoring this data closely and perform re-entry calculations on a regular basis to monitor any changes in the space station’s orbit or decay rate.”
Tiangong-1 will meet a fiery death upon its re-entry, mostly burning up in the atmosphere. Because of the spacecraft's size—34 feet by 11 feet, and 18,740 pounds—The Aerospace Corporation says some material may survive. Any material that does reach the planet may be highly toxic and corrosive. "For your safety, do not touch any debris you may find on the ground nor inhale vapors it may emit," The Aerospace Corporation warned.
However, with two thirds of the planet covered in water and huge areas of land uninhabited, any surviving debris are highly unlikely to land in places where they could cause any major damage.
Whether anyone will see Tiangong-1's final descent depends on where and when it enters the atmosphere. The location should be known a few days before the event. “Visibly incandescent objects from this re-entry will likely last tens of seconds (up to a minute or more) in contrast with the vast majority of natural meteors, which last mere seconds,” the corporation said in a statement.
“Depending on the time of day and cloud visibility, the re-entry may appear as multiple bright streaks moving across the sky in the same direction.”
Tiangong-1 was launched in 2011 as China’s first space station. It was unmanned but had a habitable experimental module so astronauts could stay there. Two manned missions took place over its five-year operational period and were noted for including the nation’s first female astronauts, Liu Yang and Wang Yaping.
The space station officially ended its service in March 2016. A few months later, it was widely reported that China was no longer in control of the spacecraft. In September 2016, the space agency confirmed the news in a press conference. The plan for a controlled re-entry, in which the spacecraft’s descent could be managed with a thruster burn, was no longer possible.
Instead, the spacecraft has been on a decaying orbit, and its altitude will continue slowly decreasing until reaches the upper atmosphere. When that happens, Tiangong-1 will make its uncontrolled re-entry.
In a note sent to the United Nations Office for Outer Space Affairs in May, China’s space agency said the orbit has been under close surveillance since control was lost, and that the spacecraft is currently descending at a rate of about 520 feet per day. “China attaches great importance to the re-entry of Tiangong-1,” the agency said. “China will make strict arrangements to track and closely monitor Tiangong-1 in its orbital development and will publish a timely forecast of its re-entry.”
While the uncontrolled re-entry of Tiagngong-1 is a significant event, it is not the biggest. The Mir spacecraft, for example, weighed over 260,000lbs when it was deorbited in 2001. "We have been making a special case of examining Tiangong-1 because of likely public and media interest in a re-entering space station; not because it is a particularly dangerous re-entry," Abraham says.
This story has been updated to include quotes from Andrew Abraham.