As more space junk falls to Earth, will China clean up its act?

In the next few days, a 23-ton rocket will plummet to Earth at about 15,000 miles per hour. Much of it may burn on re-entry, but a significant amount may not.

It could land as a single piece, but more likely many, scattered over an area up to several hundred miles in diameter. Scientists have narrowed down the likely impact zone to latitudes 41 degrees north and 41 degrees south, a region that covers much of the US and South America, Africa, the Middle East, most of Asia and all of Australia, except the island of Tasmania.

Beyond that, predictions are uncertain.

“A few hours after it re-enters the atmosphere we’ll know where it was,” said Dr. Jonathan McDowell, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics. “A few hours earlier we might know when in three hours… But in that time the rocket is going around the Earth at 17,000 miles an hour. So if you’re an hour off, you’re also 17,000 miles off.”

In all likelihood, the space junk discarded from China’s Long March 5B launch last Sunday will not reach a populated area. Although 80% of the world’s population lives in the risk zone, only 0.1% is considered populated.

“Everything else is ocean, forest or farmland,” said Dr Shane Walsh, a researcher at the International Center for Radio Astronomy Research. “It is extremely unlikely to cause damage or loss of life.”

Space watchers may not be too worried, but they’re not exactly happy about the situation. The impact will be similar to a small plane crash, experts say, and probably far less deadly than the missile strikes and accidents that happen elsewhere every day. But the risk could be mitigated.

Sunday’s launch was the third in the 5B series, which delivered a new laboratory module to the Tiangong space station. Most nations’ rockets separate the launcher from the payload before leaving the atmosphere, with an additional engine on the payload providing a final push and allowing the launcher to fall in a more predictable manner.

But it seems that China doesn’t want to spend weight on the second engine, and its 5B rocket, one of the largest in use, instead of pushing fully into orbit before separating. The bus-sized launch section travels in orbit for days to weeks before re-entering Earth’s atmosphere. somewhere

In May 2020, two villages in Côte d’Ivoire were hit by objects, including a 12-meter section of pipe, that appeared to be from a Chinese Long March 5B that was expected to land that day.

Debris that fell from space in the village of N’Guessankro in central Ivory Coast in 2020. Picture: AFP/Getty Images

After the second 5B launcher landed harmlessly in the seas near the Maldives last year, a NASA administrator, Bill Nelson, accused China of “failing to meet responsible standards for its space debris.”

Chinese authorities reject the accusation. This week, its foreign ministry spokesman, Zhao Lijian, said that Chinese space exploration had always acted “in accordance with international law and … customary practice”, and that the likelihood that the waste cause damage was “extremely low”.

Zhao said the unit had been designed with unspecified “special technology” and that the “overwhelming majority” of its components would burn up on re-entry into the atmosphere.

Walsh said: “They claim to have learned from the last two releases and added some method of control, but the EU monitoring network showed that this unit is falling, which means it is not controlled.”

Professor Chao Chi-Kuang, head of the space science department at National Taiwan Central University, noted that there had been other uncontrolled debris flows that hit Earth, and not just from China. Famously, Nasa was fined $400 for littering when parts of its Skylab space station landed in Western Australia in the 1970s. (He hasn’t paid yet.)

Chao said China’s releases were more unpredictable, and with larger pieces, and “of course people are afraid in this case,” but also accused the media of alarmism. “People think that there is something very heavy and big above our heads. But I think if China can avoid damage, they will avoid it,” he said.

In the event that the debris touches something or, worse, someone, the affected people will be liable for compensation. But otherwise, there are no international rules to prevent or restrict uncontrolled entries.

“It’s an interesting quirk of space law that if you do harm you’re responsible for it, but if you do something risky and get away with it … then you get away with it,” McDowell said.

The US and EU have incorporated risk assessments and will not launch if there is more than a one in 10,000 chance of causing injury. China seems to have a much lower bar.

In April, residents of a remote part of India found what appeared to be large parts of a Chinese Long March 3B rocket launched in February. Launches from the inland Xichang satellite launch site routinely rain debris into communities, with officials issuing evacuation notices for residents to “adjust your location quickly.”

Walsh said China was rightly proud of its space program and that the launches should be a public relations coup. Instead, there are global headlines of varying levels of alarm.

McDowell and Walsh hope the bad publicity will encourage changes in future releases. “I think they’re a little embarrassed by the bad publicity,” McDowell said. “I think they know this is considered a problem now. They may never admit it, but maybe we’ll see – without them saying it – that the next generation [of rockets] he’ll behave better and come back in more safely.”

Leave a Comment

Your email address will not be published. Required fields are marked *