The Long March 5B, a 22-ton Chinese rocket, crashed back to Earth this weekend. Where will it land?

When you are asked, “What is it?” this weekend, here’s your answer: Long March 5B, a 44,000-pound rocket body spinning toward Earth.

But scientists aren’t sure when and where this debris is — from the Chinese launch last Sunday Wentian space station module — about to land. The Aerospace Corporation did release the latest prediction path for the debris – with the disclaimer that it’s too early to be sure.

Experts believe that 20 percent to 40 percent of the massive rocket’s body mass will survive its fiery journey through Earth’s atmosphere to the planet’s surface, but not intact. Seventy percent of the planet is covered in oceans, so the odds are that whatever remains of the rocket will land in water, but that’s not guaranteed.

Shrugging in response to the potential danger of the Long March 5B debris is nothing new. Aaron Boley, co-director of the Outer Space Institute and planetary astronomer at the University of British Columbia, said about 70 percent of rockets that orbit and reenter Earth’s atmosphere do so in an uncontrolled way, and rocket debris is only part of that risk.

In April, a metal ring 6 to 10 feet high fell into a village in the Indian state of Maharashtra. In 2020, a 39-foot-long metal pipe landed in two villages in Ivory Coast. In 2016, two tanks of rocket fuel landed on the Indonesian islands. Earlier this month, part of a SpaceX baggage capsule fell into paddocks in New South Wales, Australia.

“Every time we launch a rocket, we roll the dice,” Boley said. “And the thing is, we roll a lot of dice, many times.”

Rockets are carriers for anything put into orbit, including individual satellites and constellations of satellites, telescopes, engineering projects, and research modules. In 2021, there will be more than 130 successful orbital rocket launches globally — a record — and 2022 is on pace to deliver many more as space development skyrockets.

“In the future, we may have companies launching rockets to build their own space stations, whether that’s for tourism or manufacturing in orbit,” Boley said.

Rocket trajectories can take several forms. Often, they gradually break apart during the ascent, spilling a heavy booster or empty fuel tank in a controlled process called staging. When staging takes place in the suborbital zone—where Earth’s gravity still has a complete or near-perfect effect on the dropped engine—the launch team can precisely plan where they will land (over the ocean).

Another mission path requires that some rocket stages be left in low-Earth orbit (LEO) – a region loosely thought to be between 180 and 1,250 miles above Earth – where they are allowed to float, effectively, as space junk.

Technology exists to curb danger. It’s just that not everyone uses it.

This is not a technology issue. Some rockets, like SpaceX’s Falcon 9, have re-startable engines, which can redirect re-entry to an uninhabited (by humans) place on Earth, and sometimes even a full round trip with landing pads ready and waiting for them.

But not all rockets are equipped with this technology, and even if there were, “there are additional costs associated with recovery,” Boley said. “The customer can decide on a cheaper option, or the launch team can decide that it’s easier to throw the object in orbit.”

So rocket bodies—including the enormous Long March 5B, which were not equipped with a re-starting engine—were left to litter the LEO. This is a policy decision that many countries, including the US, seem to accept.

More than 1,000 rocket bodies and thousands of satellites are currently hurtling through LEO, completing a revolution around Earth every 90 to 120 minutes.

Gradually, this slow orbital journey—tracked most vividly and shared online by the Aerospace Corporation, an independent, government-sponsored nonprofit organization—is slowed by obstacles, the same aerodynamic forces that naturally fight airplanes or race cars, and fall into the ground. Earth.

“It’s all kind of funny, because orbit is nothing more than falling toward something and constantly getting lost. And finally, the pull of the gas made it so, no, this time it would hit.”

Where space debris is not always left alone

The eventual landing spots for these many uncontrolled entries aren’t necessarily random—with many launching and landing around the equator.

In studying the orbital trajectories of more than 1,500 rockets that have deorbited over the past 30 years, Boley and a team of researchers at the University of British Columbia estimated that there was between a 10 and 20 percent chance of casualties from rocket debris. .

This is far from the 0.01 percent risk threshold the United States applied for its launch, a casualty assessment that is often overlooked. “To my knowledge, there is no paper trail for the decision-making process leading up to it [0.01 percent] number that has been applied to launch and re-entry,” said Boley.

“But we can’t paint extraterrestrials as bad guys,” said Timiebi Aganaba, assistant professor and senior global future scientist at Arizona State University who specializes in environmental and space governance. “[When the policies on space development were set], there are so few launches; it’s not something that, 10 years ago, anyone would talk about.”

But now, as space continues to be commodified and rockets fly more frequently, both Boley and Aganaba agree that rocket debris is a matter of collective action. Boley said the solution would require the international community to come together and agree on risk mitigation regulations.

How and when these rules will be created and followed has to be seen. It may take some time until “someone wins the lottery, so to speak,” unfortunately hit by space debris, Boley said. “It’s likely not you, but someone who will.”

This article has been updated. Thanks to Lillian Barkley for copying edits to this article.

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