Within the next 72 hours China’s first space station, the Tiangong 1, is going to end its life. It is already scraping the extreme upper atmosphere of Earth and the air resistance is slowing down the 7.7 metric tons (8.5 ton) spacecraft with every passing second. It is coming down somewhere, but scientists don’t know exactly when or where.
Current Stats of Tiangong 1
The current speed of the Tiangong 1 (27 March 2018 at 12 noon PDT) is at 28,000 km/hr (17,400 mph) and it is at an altitude of just under 200 km (125 mi) at the lowest point in its orbit. Its orbit has lowered by over 60 km in the last two months. As Tiangong 1 approaches 160 km the air resistance will be too much for it to maintain orbit.
Statistically, Tiangong 1 will most likely fall into an ocean; however, there is a possibility that it could fall on southern Europe, southern Asia, Africa, Austrailia, South America, Central America, or the United States.
Normally, objects like this are brought down in a controlled fall using thrusters to slow the craft down at a specific time and location. In the case of Tiangong 1, the Chinese engineers had planned to bring it down in a controlled reentry until they mysteriously lost contact with it two years ago.
China said they had shut down telemetry with Tiangong 1 in March of 2016. They didn’t admit they had lost control of it until amateur astronomers had confirmed the space station was tumbling in space a few months later. Without the ability to communicate with the space station, there is no way to command the thrusters for a controlled reentry.
The experts are currently estimating that Tiangong 1 will come down on Easter Sunday (1 April.) Since Earth’s atmosphere expands and contracts with solar activity, the air resistance is not consistent. There is a critical point when the air resistance will win its battle with the space station and the orbit will decay exponentially. At that point, the spacecraft will begin a rapid breakup as it descends through the thicker atmosphere.
For what it’s worth, my guess is 7:42 am PDT on Saturday, 31 March.