An Asian studies expert and amateur satellite tracker have voiced their concerns over the possibility that China’s Tiangong-1 space station may be de-orbiting without control from the ground. The station, launched in 2011, was a temporary testbed for the technologies for Tiangong-2, a permanent station scheduled to be launched in September of this year. Beijing’s original plan was to de-orbit the spacecraft in 2013, but Tiangong-1, Chinese for "Heavenly Palace 1", remained in orbit after that date, conducting long-term endurance tests of the now unmanned station’s components.
Last March, China’s Manned Space Engineering Office reported that telemetry between the station and ground control had been terminated, due to the station’s mission having run over two-and-a-half times its intended lifespan, and that the station is expected to de-orbit on its own over the next few months.
However, senior research fellow Dean Cheng at the Heritage Foundation’s Asian Studies Center is concerned over Beijing’s lack of communication regarding Tiangong-1’s status, and feels it may mean that they may not have control over the spacecraft. Amateur satellite tracker Thomas Dorman also shares this concern: "The suggestion has been made (that) the reason China hasn’t done re-entry of Tiangong-1 is, the space station is low on fuel, and China is waiting on a natural decay to a much lower orbit before they can do a burn to bring the station down."
"It could be a real bad day if pieces of this came down in a populated area … but odds are, it will land in the ocean or in an unpopulated area. But remember — sometimes, the odds just do not work out, so this may bear watching."
Other experts have a differing opinion, feeling that Heavenly Palace may be aloft for some time yet. Referring to a recent boost made to Tiangong-1’s orbital altitude, the Center for Space Standards & Innovation’s T.S. Kelso says that this may be much ado about nothing: "That reboost put it higher than it had been any time prior to that in its mission."
"But we might expect to see the rate of decrease in altitude – the slope between reboosts – increase if it was tumbling, since the station would have higher drag. Instead, we see the slowest decrease in altitude in recent years – consistent with the lower drag at a higher altitude."