Like its predecessors — including NASA’s Skylab and the former USSR’s Salyut 7 — China’s first successful space station Tiangong-1 is about to plummet from orbit and break apart on re-entry, likely raining space debris onto Earth’s surface. The only question is: exactly when and where will the pieces hit?
According to expert sources including the US’s Aerospace Corporation and the European Space Agency, the station will likely re-enter the atmosphere anywhere between late March and mid-April.
Launched in 2011, Tiangong-1 was never intended to remain in orbit for the long term, and the Chinese government announced in 2016 that technical difficulties are preventing them from making a controlled re-entry. While most of the 8.5-ton spacecraft will burn up from atmospheric friction, Aerospace Corporation reports that “a small amount of debris” may reach the surface intact, and would fall within a region “a few hundred kilometres in size.” They estimate the craft could re-enter anywhere from northern China to parts of Europe, New Zealand, southern Africa and both North and South America.
The main concern seems to be the possibility the station contains a highly-toxic fuel known as hydrazine… but before you panic, bear in mind these experts claim the odds of the debris striking a populated area are (literally) astronomical.
“In the history of spaceflight no known person has ever been harmed by reentering space debris,” Aerospace says in a report cited by The Guardian. “Only one person has ever been recorded as being hit by a piece of space debris and, fortunately, she was not injured.”
Nevertheless, some scientists urge people to be careful and pay attention to tracking reports on the debris.
“Every couple of years something like this happens,” Harvard astrophysicist Jonathan McDowell told The Guardian, “but Tiangong-1 is big and dense, so we need to keep an eye on it.” He also explained how constantly-changing conditions in orbit made it difficult to predict the descent with more accuracy.
“It is only in the final week or so that we are going to be able to start speaking about it with more confidence,” McDowell revealed. “I would guess that a few pieces will survive re-entry. But we will only know where they are going to land after the fact.”