When the Chinese space agency launched its space lab Tiangong-1 in 2011, little did they expect it to come ‘crashing’ back to Earth six years later.
Chinese officials told the UN in 2016 they had lost the ability to correct the station’s altitude and expected it to plummet to the ground between October 2017 and April 2018. But Harvard University astrophysicist Jonathan McDowell told the Guardian it now is entering the atmosphere at an even more accelerated timetable, and will probably see its demise in the earlier part of that range.
“Now that [its] perigee is below 300 kilometers [186 miles] and it is in denser atmosphere, the rate of decay is getting higher,” McDowell said. “I expect it will come down a few months from now—late 2017 or early 2018.”
He added there is a small chance chunks of the station weighing up to 220 pounds (100 kilograms) could remain intact and hit the ground at high speed.
The Tiangong-1 is very small by space station standards, and can only accommodate a small crew of three taikonauts. Its primary purpose is to serve as a prototype for future generations of Chinese stations and support craft.
It is unlikely scientists will have more than a few hours’ heads-up on when and where Tiangong-1 will crash, but it is unlikely to come down in a densely populated area where there would be appreciable odds of anyone being hurt or injured. As the Guardian noted, on several occasions spacecraft like NASA’s monstrously huge, 77.5-ton Skylab or Upper Atmospheric Research Satellite have made uncontrolled descents towards the Earth, but none of them have ever been found to have killed or hurt anyone.