China's 9.5-ton space station to fall to Earth in coming days

China launched the Tiangong-1 space station in 2011. The 9.4-ton space station orbited the Earth without any Chinese astronauts on board. In March 2016, China said it had lost contact with Tiangong-1 after it “completed its historic mission.”

Tiangong-1 could fall into Earth's atmosphere around April 1, according to predictions by Aerospace Corp, a nonprofit space research organization.

No one knows exactly where Tiangong-1 will fall, but it is highly likely to be in the ocean. According to calculations, a person's chances of winning the Powerball jackpot are 1 million times higher than being hit by debris from Tiangong-1.

To orbit the Earth at an altitude of 400 km, any spacecraft must reach a speed of more than 28,000 km/h, which means it completes one orbit around the Earth every 90 minutes. Even at this altitude, spacecraft like Tiangong-1 are pulled toward Earth. If they do not increase their speed regularly to adjust their orbit, they will slow down and fall.

“Above 100 kilometers, the atmosphere is much thinner. You can’t survive it, but it’s still thick enough to slow you down,” said Jesse Gosner, an instructor at the Air Force’s Space Operations School.

“It’s like a guessing game, there’s no way to know where it’s going to fall.” Even up until the day it falls, the odds are still within six days. It could fall as early as March 29 and as late as April 4.

Gossner said this uncertainty is due to the nature of Earth’s atmosphere and the speed at which objects fall. “Have you ever thrown a rock into a lake? It bounces a few times, then it falls into the water.” The Tiangong-1 space station, Gossner said, is like that rock.

“It could bounce a few times in the atmosphere because it’s moving so fast,” he said. “If it hits a soft surface, it would be like a stone bouncing on water. But it could also fall straight down and sink straight down.”

“Even if you knew exactly where it hit the atmosphere, the debris and the contents would be scattered over a very wide area. It’s really a guessing game. There’s no way to know where it will land.”

Tiangong-1 will most likely fall into the ocean, since water covers 71% of the Earth’s surface. In fact, space agencies often try to steer large spacecraft into the Pacific Ocean, because it’s the largest and least likely to cause harm.

Some pieces of the spacecraft are still likely to fall to land because the collision with the Earth's surface created a lot of debris, with unpredictable trajectories.

However, experts maintain that it is almost impossible for the Chinese space station to fall into a populated area.

“Nothing is impossible, but since the beginning of the space age, only one woman has suffered a shoulder injury from falling space debris,” said Ailor of Aerospace.

In the event that a piece of titanium, a computer, or other debris falls on the roof or window of the house, they will receive appropriate compensation, according to international space law. “China will be held responsible if they cause injury or damage to property,” a NASA representative shared.