This weekend a huge recall of a Chinese rocket will begin an uncontrolled fallback to Earth from space – and due to its considerable size and weight, parts of it may survive the descent through our planet’s atmosphere and hit the ground. The chances of the rocket hitting someone and killing them are extremely rare, but a similar Chinese rocket falling last year sparked major concern around the world, which means this rocket is likely to do the same.
The booster is part of a Long March 5B rocket, launched July 24, sending a new module into orbit for China’s growing Tiangong space station. Once the giant rocket hits space, it gets rid of a pretty massive part of itself: its main thruster. This booster stays in orbit, straddling the planet before finally falling back to Earth. Since the rocket portion is over 100 feet long and weighs over 22 tons, it is possible that up to 9 tons of material survived the fall.
Space trackers are doing their best to predict exactly when and where the Long March 5B booster will drop. The situation is very similar to that of last year’s global scare about an out-of-control chinese rocket who fell back to earth, as well as a similar uncontrolled re-entry in 2020. Both of these cases also involved a Chinese Long March 5B base booster, which does not have the ability to dump itself in a controlled manner. Fortunately, last year the rocket fell in the sparsely populated Indian Ocean, but in 2020 this rocket dumped debris off the coast of Ivory Coast, sending metal pipes and other objects into villages. without causing any injuries.
Yet the risk to this year’s average rocket man is so low that it shouldn’t keep anyone up at night. In fact, for anyone on Earth, there’s a six in 10 trillion chance that some part of that rocket will hit you and cause some sort of casualty or injury, according to Aerospace Corporation, a nonprofit organization that does space research and development, as well as providing technical advice on spaceflight. But, the fact that space trackers must continue to deal with this kind of problem without knowing when and where the rocket will fall is frustrating.
“Why are we worried? Well, it caused some property damage last time, and people need to prepare for that,” said Ted Muelhaupt, space traffic expert and consultant to the Aerospace Corporations Office of Chief Engineer, during the interview. a rocket speech. “Besides, it’s not necessary. We have the technology to not have this problem.
Reports of a 12m long object crashing into the village of Mahounou in Ivory Coast. It is directly on the CZ-5B re-entry track, 2100 km downstream from the Space-Track re-entry location. It is possible that part of the scene passed through the atmosphere this far (photo: Aminata24) pic.twitter.com/yMuyMFLfsv
—Jonathan McDowell (@planet4589) May 12, 2020
In the United States and Europe, the rule for space operators is that if there is going to be some kind of uncontrolled re-entry of space debris into the Earth’s atmosphere, there must be a less than 1 in 10,000 chance that the falling object will cause some kind of casualty or ground injury. This is a particularly high bar to cross, which is why US and European missions must be vigilant about how they dispose of the rockets they send into space. “Basically, once you’ve finished delivering your payload, you spin your rocket, fire up the engine, and send it back out into the ocean somewhere, usually somewhere where there’s no population,” said said Marlon Sorge, space debris expert and technical member of the aerospace company, said. “You do that, and you’ve pretty much mitigated the risk there.”
Controlled disposal is something that most launch vendors around the world already do. SpaceX and United Launch Alliance, for example, deliberately drop parts of their rockets above the ocean after launching into space. Additionally, SpaceX’s Falcon 9 rocket core is famous for returning to Earth and landing upright — either on a drone or on a landing pad — after its flights. The Long March 5B base booster does not have this ability. Once it’s launched into orbit, the rocket’s core engines can’t really re-ignite. “They’re designed for a single burn,” says Jonathan McDowell, an astrophysicist at the Harvard Center for Astrophysics and an expert in space tracking. The edge. “And so this thing only burns once, then burns out, and it’s dead.” Then we just have to wait for it to fall back to Earth as its orbit decreases over time.
The Aerospace Corporation estimates that there is between 1 in 1,000 and 1 in 230 the risk of a victim from the fall of the Long March 5B booster. This is 10 times above the threshold of 1 in 10,000, which is why there is increased vigilance around this specific case. And every time China does a stunt like this, the US isn’t particularly happy about it. “Space nations must minimize the risks to people and property on Earth from space object reentries and maximize transparency regarding these operations,” said NASA Administrator Bill Nelson. said when the Long March 5B of 2021 fell. “It is clear that China is failing to meet responsible standards regarding its space debris.”
China apparently took note of the criticism. During this most recent launch, a Chinese official during the CGTN launch livestream mentioned that they made improvements to get rid of the booster after launch. “The last segment, or base segment, once it [enters] in orbit, it also [works] as a spacecraft,” Xu Yansong, former director of international cooperation at the National Space Administration of China, said during the livestream. “So we will have to bring him back in a safe and controlled way. So one of the first missions couldn’t do it, but later we improve our technologies. And so what we call last stage passivation was conducted, so that we could safely bring the last fuselage back.
Our latest prediction for #CZ5B the reentry of the rocket body is:
Jul 31, 2022 00:24 UTC ± 16 hours
Re-entry will be via one of the ground tracks shown here. It is still too early to determine a significant debris footprint. Follow this page for updates:https://t.co/SxrMtcJnj0 pic.twitter.com/CZRQBClOAg
— The Aerospace Corporation (@AerospaceCorp) July 28, 2022
However, it doesn’t seem like anything has changed since the last scare. In fact, the European Union Space Surveillance and Tracking Network found that booster tumbles in space, indicating that there is no control over the object. So we’re going to go through the whole prediction process where it’s going to come back down. At present, the European Union, US Space Force and Aerospace Corporation’s best estimates of when it will fall are late Saturday evening or early Sunday morning. As for where it will go down, it will be somewhere between 41.5 degrees North and 41.5 degrees South. This means that around 1 billion people living north and south of these lines are not at risk. (Boston and parts of Tasmania – congratulations, you’re just outside the zone.) But 88% of the human population lives in that range, according to Aerospace Corporation.
The forecast will become more accurate with each passing day as we get closer to Sunday, and the aerospace company is continuously updating its predictions here. The European Union also follows the trail, just like the Space Force. As for what to expect when the rocket drops? Based on past experience, the debris could extend over an area of several hundred kilometers along the rocket’s orbital path. Some parts, depending on their size and weight, may hit the ground slowly, while others may hit the ground quickly, at speeds of up to hundreds of kilometers per hour. Ultimately, it’s a guessing game, and we may not know much about this event until the rocket actually drops. “The story of getting things back on track has been a story of continued surprise,” McDowell says. “How long do they actually survive the start of the school year? Sometimes more survivors than you initially imagined.
But even though there’s a little more risk than usual with this falling rocket, it’s important to keep things in perspective. “The risk for any given individual in any given year of having their head crushed by space debris is one in 100 billion,” Muelhaupt said. “You’re 80,000 times more likely to be hit by lightning than by space debris. But that doesn’t mean it’s a good thing to do.
So enjoy this new set of uncertainties about falling rockets. Once this is over, we’ll probably have to do it all over again. There’s another Long March 5B launch tentatively planned for this fall.