A large Chinese rocket body is likely to return to Earth tomorrow (July 30), but no one knows exactly when or where.
The Long March 5B rocket’s 25-ton (22.5 metric tons) main stage will re-enter Earth’s atmosphere tomorrow at 2:05 p.m. EDT (1805 GMT) plus or minus five hours. The latest forecast from The Aerospace Corporation researchers (opens in new tab). The booster spent less than a week in orbit; he Wentian went upThe second module for China’s Tiangong space station on July 24.
Most of the rocket body will burn up, but large parts of it will survive the fiery passage—probably From 5.5 tons to 9.9 tons (opens in new tab) (5 to 9 metric tons), according to the Aerospace Corporation’s Center for Orbital Reentry and Debris Research.
Related: The largest spacecraft to fall out of space
Based on the orbit of the main stage, we know that these bits will land somewhere between 41 degrees north latitude and 41 degrees south latitude. Most of Europe and North Africa appear to be out of the firing line, according to the latest forecast. We also know that the debris “footprint” will be large, with some pieces likely to fall hundreds of miles apart.
But given the impreciseness of the reentry window, it’s hard to say much more than that right now. The rocket body is orbiting Earth at about 17,000 mph (27,400 km/h), so a one-hour error in predicted re-entry time translates into a 17,000-mile error in track location.
This inaccuracy is not an accusation space junk researchers and satellite trackers; it is really difficult to predict the fall of such debris.
“The thing is, the density of the upper atmosphere changes over time; there’s actually air in there,” said astrophysicist and satellite tracker Jonathan McDowell of The Aerospace Company during a live discussion of the Long March 5B crash yesterday (July 28) on Twitter. ).
“And it’s impossible to predict exactly at what point a satellite will pass through enough of the atmosphere to melt and break up and eventually re-enter,” added McDowell, who is based at the Harvard-Smithsonian Center for Astrophysics.
The long March 5B core does not follow a smooth, predictable path through the upper atmosphere, further complicating forecasting efforts.
The rocket body “seems to be falling in a certain way, meaning there’s a constantly varying amount of drag on it,” said Matthew Schoeppe, senior director of commercial space at California-based tracking company LeoLabs, during yesterday’s discussion. . “And because we don’t know exactly how it flies, we can’t accurately model it.”
However, based on geography alone, we can make some educated guesses about the rocket crash. For example, the Long March 5B core is likely to re-enter over water, as oceans cover more than 70% of the Earth’s surface. Given that most people live in large metropolitan areas separated by many miles of open space, even a fall on terra firma is unlikely to result in injury or damage to infrastructure.
“Really, there’s a 99.5 percent chance that nothing will happen,” Ted Muelhaupt, a consultant with the Aerospace Corporation’s Office of the Corporate Chief Engineer, said during yesterday’s discussion.
So there is there is no reason to panic. But don’t worry, because McDowell, Shouppe and Muelhaupt stressed that the impending crash is very preventable.
Other orbital rockets are not prone to such problems; their large main stages are directed into the ocean or uninhabited areas shortly after liftoff, or in the case of SpaceX Sahin 9 and Falcon Heavy launchers descend for vertical landing for future reuse. The Long March 5B core, on the other hand, reaches orbit with its payload and remains aloft until atmospheric drag brings it down uncontrollably.
We saw such drops after two previous missions of Long March 5B, launched in May 2020 and April 2021. Missile body fell upon the empty ocean After takeoff in April 2021, however, the May 2020 mission ended in a crash that spread debris across parts of West Africa. And some of this spacecraft is visible Landed in Ivory Coast (opens in new tab).
Editor’s note: This story was updated on July 29 at 3:40 p.m. ET with the latest forecast from the Aerospace Corporation.
Mike Wall is the author of “There (opens in new tab)” (Grand Central Publishing, 2018; illustrated by Carl Tate), a book about the search for alien life. Follow him on Twitter. @michaeldwall (opens in new tab). follow us on Twitter @Spacedotcom (opens in new tab) or where Facebook (opens in new tab).
Leave a Comment