The Chinese space station, “Tiangong-1”, is headed towards Earth. Chinese officials have also revealed that they currently have no clue where the space station is going to crash, but have predicted that it is to occur sometime in 2017. The craft is approximately the size of a bus (a length of about 34 feet and width of 11 feet), weighing 8.5 tonnes. It will most likely re-enter our atmosphere in small pieces.
The Tiangong-1, which translates to “heavenly palace”, was originally launched in 2011 as an attempt to practice and carry out experiments relating to living in space and docking procedures with other space crafts. It was only built and intended for two year missions. Only recently, on September 14th 2016, did Wu Ping, the deputy director of China’s manned space engineering program, reveal that they had lost contact with the space craft back in March of 2016. Reasons why China’s space program have lost contact with Tiangong-1 currently remain unclear. While most unmanned space crafts burn and break apart upon entering the Earth’s atmosphere, this is usually closely monitored and highly controlled.
Unfortunately, having lost all contact with the satellite, the Chinese space agency has very little influence over when and where it will crash. As of September 23rd, Tiangong-1 was orbiting above the Earth at approximately 370 kilometers. It has been losing just over 100 meters a day from both the Earth’s gravitational pull and atmospheric drag. By November 13th, the station will be roughly 364.9 kilometers above the Earth, having lost over 5,100 meters.
When satellites reach the end of their intended lifespan, there are two options to dispose of them. The first is blasting it even further into the icy depths of space where it will never be seen again. The second option consists of slowing down the satellite using the last of its fuel so it can fall out of orbit and burn up in the atmosphere. While smaller satellites disintegrate upon entering the atmosphere at thousands of miles an hour, bigger crafts, i.e. Tiangong-1, may survive and are usually redirected to an area in the South Pacific Ocean known as the “spacecraft cemetery”. The cemetery is the safest place for satellites to crash because it is the point farthest away from any piece of land.
So where will the space station crash? Nobody is able to know or even roughly estimate the site of impact at this time. Even when satellites reenter our atmosphere under controlled descents, no one is able to predict exactly where it’s going to crash due to factors like the descent angle, how much of the craft is left to burn, and if there are multiple fragments. Taking into account all these factors, means that the craft could crash practically anywhere on Earth.
Despite all of this, officials claim that there is only a small chance that the satellite will hit a populated area. This is partially due to the fact that Tiangong-1 is hollow, which will cause it to burn up upon re-entry. Additionally, most of Earth’s surface (71%) is covered in water, with population density being a specific area on land, lessening the chance of the satellite posing any danger. However, that is only an estimate, and the only way to know for sure will be to watch the skies sometime in 2017.
