The Tiangong-1 is out of control and is expected to re-enter Earth’s atmosphere in less than a year with the potential for small debris and chemical material to make it to the ground.
The Tiangong stopped functioning on March 16, 2016 when its systems ceased communicating.
The station’s current average altitude is 217 miles (349 kilometers), its orbit is decaying at a daily rate of approximately 525 feet (160 meters).
When Will It Re-Enter
According to the U.N. the space station is expecting re-entry between October 2017 and April 2018, they’ve provided a margin of error for two months on either side.
Most of Tiangongs structural components will burn up upon re-entry, and the “probability of endangering and causing damage to aviation and ground activities is very low,” the notification adds.
Noted earlier, it’s unlikely (but possible) that any small debris makes it to the ground. “It is highly unlikely that debris from this reentry will strike any person or significantly damage any property,” Aerospace Corporation representatives wrote in a Tiangong-1 re-entry FAQ.
A larger concern is a an onboard substance known as hydrazine.”Potentially, there may be a highly toxic and corrosive substance called hydrazine on board the spacecraft that could survive re-entry. For your safety, do not touch any debris you may find on the ground nor inhale vapors it may emit.”