Concerns are growing that a Chinese space rocket’s uncontrolled entry into Earth’s atmosphere could scatter debris across populated parts of the United States.
The Long March 5B booster is too large to burn on entry and will disintegrate, potentially raining down bits of metal accelerating at terminal velocity.
According to the Center for Tropical and Reentry Debris Studies (CORDS) “More than 88% of the world’s population lives under the influence of potential re-entry debris”.
Experts at CORDS from the Aerospace Corporation warned that “as a general rule … 20-40% of the mass of a large body will reach Earth” depending on the body.
In the case of the Long March booster, which weighs 23 metric tons, that means between 4.6 and 9.2 metric tons will hit the ground – the equivalent of a dozen 1963 Volkswagen Beetles.
In a Q&A on the Aerospace Corporation blog, the company said the booster is one of the largest objects to re-enter Earth after reaching orbit.
Most of the time, rocket boosters are not designed to reach orbit, but to launch their payloads into orbit while landing in a safe place.
When a spacecraft is ejected from orbit, it is usually done in a controlled manner, with the engines running to drop the craft into Earth’s orbit and choose where it will land – often called the “spacecraft graveyard” at Point Nemo in the Pacific Ocean.
The “spacecraft cemetery” Point Nemo as seen on Google Earth. Pic: Google
This is known as controlled re-entry as operators can identify the final landing point and debris footprint.
However, should the booster rocket enter orbit and return to Earth normally, its final landing place will not be known until just hours before it hits Earth.
This isn’t the first time a Chinese booster has threatened populated areas when crashing to Earth, and similar uncontrolled re-entries occurred in 2021 and 2020.
In May 2020, pieces of the booster fell over Ivory Coast, according to an analysis by astronomer Jonathan McDowell, damaging several buildings but leaving no one injured.
In an article responding to the latest concerns, China’s state-owned Global Times claimed that the Western media’s response showed “sour grapes”.
The paper also claimed that China had an “impeccable safety record” on uncontrolled re-entry, despite Mr McDowell’s analysis.
She added that the criticisms were distortions intended to undermine China’s successes in the aviation sector because the United States is “running out of ways” to stop that development through other means.
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