Space.com reports (Tor-friendly link) that amateur satellite tracker Thomas Dorman has created imagery that suggests China's Tiangong-1 space station "is in a slow roll." If that is the situation, its motion is not under control and its solar panels are not aimed at the Sun.
In March, official news agency Xinhua reported that "Tiangong-1 terminated its data service" and that
The flight orbit of the space lab, which will descend gradually in the coming months, is under continued and close monitoring, according to the [manned space engineering] office, which said the orbiter will burn up in the atmosphere eventually.
The official statement and Dorman's observations have led to speculation that the craft's descent may take place in an uncontrolled manner, increasing the possibility that debris will fall in populated areas.
Additional coverage:
(Score: 3, Interesting) by butthurt on Thursday July 14 2016, @07:51PM
It's customary to carry enough fuel for a de-orbit manoeuvre: it was done with the Salyut stations, with Skylab, and with Mir.
I'm not sure how much the solar panels affect the descent. At a guess, they might break off when, or before, the forces on them became enough to drastically change the motion of the main body of the craft. Certainly the panels don't make a craft's descent more predictable. Controllers wanted Skylab to come down in the ocean south of South Africa, but it actually came down on Western Australia.
https://en.wikipedia.org/wiki/Skylab#Re-entry [wikipedia.org]
(Score: 3, Interesting) by frojack on Thursday July 14 2016, @08:29PM
The very same Wiki link you posted says this about skylab:
NASA first considered as early as 1962 the potential risks of a space station reentry, but decided not to incorporate a retrorocket system in Skylab due to cost and acceptable risk.
So it seems unlikely that skylab carried enough fuel for a de-orbit burn, since it didn't have any engines, and required occasional orbital boosts by Apollo visits.
No, you are mistaken. I've always had this sig.
(Score: 2) by butthurt on Thursday July 14 2016, @09:53PM
Ah, I was looking at the bit that says "ground controllers adjusted Skylab's orientation to try to minimize the risk of re-entry on a populated area." Bit of a difference there. Thanks.