The China Manned Space Engineering Office said it expects the lab to reenter the atmosphere between March 31 and April 4, burning up in the process.
However, Alan Duffy, a research fellow in the Centre for Astrophysics and Supercomputing at Swinburne University of Technology in Australia, said that China’s secrecy around the space mission made the risks difficult to assess.
“The international community doesn’t know what the craft is made of, and that makes estimating the danger more challenging, as hardened fuel containers could reach the ground while lightweight panels won’t,” he said.
Space station prototype
In its UN submission anticipating the craft’s fall to Earth, China said the probability “of endangering and causing damage to aviation and ground activities is very low.”
In January, Zhu Zongpeng, the chief designer of the space lab, told the state-run China Youth Daily newspaper that China had been monitoring the Tiangong-1. He predicted that most of it would burn up when it entered the atmosphere while the rest would fall into the sea.
Fiery demise
Markus Dolensky, the technical director at the International Centre for Radio Astronomy Research in Australia, said if skies were clear witnesses may potentially see a “series of fireballs streaking across the sky.”
“It is now nearing its fiery demise as it gradually gets slowed down by the fringes of the Earth’s upper atmosphere,” he said.
It’s not uncommon for space debris, such as spent satellites and rocket stages, to fall to Earth although vessels that are capable of supporting human life are much rarer.
Experts said it’s difficult to establish exactly where the space lab will fall, but it’s expected to descend within a latitude of 43 degrees north and south of the equator.
“Some parts of the upper atmosphere are thicker than others meaning the craft slows unpredictably and since it travels around the Earth in just 90 minutes even an uncertainty of a two minutes means the craft could fall anywhere along a 1,000 kilometer track,” Duffy said.
Source : Nbcnewyork