Tiangong-1 was visited three times by Chinese spacecraft during its operational life including two manned missions.
China's "heavenly palace" is set to crash down to Earth in a matter of months after the country's space agency lost control of its orbit. It was launched to turn China into a space superpower. In recent weeks it has dipped into more dense reaches of Earth's atmosphere and started falling faster.
While much of the craft is expected to burn up in Earth's atmosphere, McDowell also reportedly said that some parts weighing as much as 100 kilograms could crash-land to Earth with scientists unable to predict where they will come down until only hours beforehand.
The Harvard University scientist forecasts Tiagong-1 "will come down a few months from now - late 2017 or early 2018".
The chance that anyone will be harmed by the debris is considered remote but China told the United Nations "Committee on the Peaceful Uses of Outer Space" in May that it would carefully monitor the craft's descent and inform the United Nations when it begins its final plunge.
China said it would inform United Nations when final dive process began, but according to Atrophysicist McDowell, station will be detected anywhere on Earth, only a few days ahead.
He said in 2016, "You really can't steer these things".
"Not knowing when it's going to come down translates as not knowing where it's going to come down", he says, adding that almost negligible alterations in atmospheric condition can change the landing location from "one continent to the next".
McDowell said a slight change in atmospheric conditions could nudge the landing site "from one continent to the next".
In 1991 the Soviet Union's 20-tonne Salyut 7 space station crashed to Earth while still docked to another 20-tonne spacecraft called Cosmos 1686.
Back in 2016, China confirmed that the station's future was out of its hands and that it would crash sometime this year or the next, but the estimate has been refined to between now and April 2018.