Better watch your back in 2018. China’s 8½ ton Tiangong 1 (Chinese for “heavenly palace”) space station will make an uncontrolled re-entry into the atmosphere sometime early next year. While friction with the air will vaporize most of the craft, it’s likely that some of the larger, denser pieces will survive the plunge despite temperatures in excess of 3,000° F (1,650° C).
Tiangong 1 was China’s first prototype space station and was used to remotely test rendezvous and docking maneuvers. In 2012 and 2013 Chinese astronauts, including that country’s first female astronauts, made short visits to the station. It remained active until March 2016, when China’s space agency reported that the ship’s service had ended. True, but amateur satellite watchers discovered that the space station was actually out of control. Last September, the Chinese conceded they’d lost contact with it and predicted Tiangong 1 would fall from orbit between early January and late February 2018.
That gives us only a few months longer to see it in the nighttime sky, where it can shine a little better than first magnitude on good passes. While no International Space Station, it’s still easy to spot during bright passes. Like the ISS, Tiangong 1 orbits from west to east, taking about 4 minutes to cross the sky. Lucky for many of us, a short series of passes begins now for the southern U.S. and on Nov. 23-24 for the northern states.
To find times to look and maps showing Tiangong 1’s track across the heavens for your location, click over to Heavens Above, log in and then click the Tiangong 1 link under the Satellites heading at left. That will take you to a list of pass times and other details. Click on a Date link and you’ll get a map of the satellite’s path for that pass.
The three-membered crew of Shenzhou 9 become the first ever astronauts to enter the Chinese Tiangong-1 Space Laboratory.
At 39 feet (12 meters) long with a diameter of 10 feet (3 meters), the derelict space station is about as big as a school bus. Some spacecraft are equipped with rockets so ground controllers can control the re-entry point, but Tiangong 1 isn’t. That makes it impossible to predict exactly where it will fall even shortly before reentry.
“Owing to the geometry of the station’s orbit, we can already exclude the possibility that any fragments will fall over any spot further north than 43°N or further south than 43°S,” says Holger Krag, Head of European Space Agency’s Space Debris Office. Those latitudes include much of the U.S. (we’re safe in the north!), Latin America, a good chunk of Europe and all of Africa. Of course, there’s plenty of ocean out there, so any surviving pieces are more likely hit water.
Still, you never know. Pieces of satellites have survived before and may again with Tiangong-1. The real show will be for the lucky ones who will get to see the spacecraft break apart into flaming pieces, torn apart by it high-speed dash through the protective envelope of Earth’s atmosphere.