China’s first space station, Tiangong-1 or Heavenly Palace, is out of control and doomed to fall to Earth in the second half of 2017. Should you worry? Not really. Two-thirds of the planet is covered in water and much of the remainder is either uninhabited or thinly so, making the chance of any one individual being struck by debris exceedingly small.
Amateur satellite trackers speculated months ago that the 34-foot (10.4-meter) long module appeared to be in trouble. Chinese officials confirmed loss of contact with the station at a recent press conference but added that the most of the 18,600 pounds (9.3 U.S. tons) would burn up harmlessly in the atmosphere during re-entry. Wu Ping, deputy director of China’s manned space engineering office, stated that the country’s first space station had “comprehensively fulfilled its historical mission”.
Tiangong-1 was launched in 2011 as a demonstration that China was a player in space. Two manned Chinese spacecraft visited the station, the first in June 2012 with a crew that included that country’s first female astronaut, Liu Yang. A year later, another crew arrived to perform maintenance and conduct experiments.
Unlike the Russian Mir space station, which was brought down in a controlled manner using its propulsion system, the Heavenly Palace lacks such niceties and instead will re-enter “naturally”. Even a couple days before reentry, the best we’ll be able to do is predict its fall to within 6-7 hours with only a rough idea of the breakup zone. Based on Tiangong-1’s orbit, denser pieces of satellite hardware such as rocket engines could partially survive the plunge, landing anywhere within a wide band of latitude stretching from 43° North to 43° South.
Big birds like this one have come down before without incident. Witness the X-ray observatory ROSAT and Upper Atmosphere Research Satellite or UARS both of which fell and burned to pieces harmlessly in 2011. Tiangong-1 is a large object that will be tracked by radar installations around the world, so there’s no fear of losing sight of it. Matter of fact, as atmospheric drag slowly claws at the station, reducing its altitude, it will gradually become brighter and move faster across the sky as the months pass.
To keep an eye on it, head over to Chris Peat’s Heavens Above site, sign in with your location and then click the Tiangong-1 link in the left-hand column for a list of flyby times for your city. When you click on a particular time, a map will pop up showing you the satellite’s path across your local sky. Coolest!
From now till early October, northern hemisphere skywatchers can watch the doomed station zip across the dawn sky’s winter constellations. Then it disappears in daylight for a week or so until returning to the evening sky at mid-month. Don’t expect an object as bright as the International Space Station (ISS)! During a bright pass, Tiangong-1 shines at first magnitude (not bad – about as bright as Deneb in the Northern Cross) but more typically around the brightness of the Big Dipper stars. Like the ISS, it moves in an arc across the sky from west to east.
Watch the launch of Tiangong-2
With a forward look to developing new space technologies, China successfully launched its second space station into orbit on September 15. Tiangong-2 will dock with manned and cargo spacecraft and accommodate two taikonauts (Chinese astronauts) for up to a month. Future crews will conduct 14 science experiments to condition for longer space flights and habitation in microgravity.
As Tiangong-2 gets prepped, we’ll have lots of time to say farewell to the first Heavenly Palace by making a point to see it sail across the sky in the coming months.