The 25-ton Long March booster rocket launched on July 24 to deliver China’s Wentian module to its Tiangong Space Station is tumbled out of its orbit and initially seemed to be hurtling toward Mexico’s Baja California peninsula near famed resort Cabo San Lucas, according to the Aerospace Corporation. The rockets are especially dangerous during uncontrolled reentry, where large portions of their mass don’t burn up safely in the atmosphere, according to Space.com, meaning as much as a 10-ton piece could make it through reentry.
“The general rule of thumb is that 20% to 40% of the mass of a large object will reach the ground, but the exact number depends on the design of the object,” Marlon Sorge, a space debris expert at The Aerospace Corporation. “In this case, we would expect about five to nine metric tons.”
— SPACE.com (@SPACEdotcom) July 30, 2022
It is the third time in the last two years that China has let its rockets fall to Earth in an uncontrolled manner. In May 2021, rocket debris also landed in the Indian Ocean. In May 2020, a falling rocket rained metallic objects down upon villages in the Ivory Coast.
Early Saturday, the rocket’s decaying orbit still had it circling the Earth every 90 minutes as of early Saturday, making it difficult to pinpoint when and where it would land.
“There is a non-zero probability” that the debris will land in a populated area, Aerospace Corporation said. But oceans, jungle and desert make up so much of the Earth’s surface that odds are strong it will land harmlessly.
“Personally, if this were coming down on my head, I’d run outside with a camera to watch it, because I think it would be more of a visual than an actual risk,” Aerospace Corporation consultant Ted Muelhaupt said Thursday.
Muelhaupt put the odds of debris hitting someone from 1 in 1,000 to 1 in 230, and the risk to a single individual much lower, at 1 in 6 trillion to 1 in 10 trillion. For comparison, the likelihood of being struck by lightning is roughly 80,000 times greater, he said.
The internationally accepted casualty risk threshold for the uncontrolled reentry of rockets is 1 in 10,000, according to a 2019 report issued by the U.S. Government Orbital Debris Mitigation Standard Practices.
Still, China insistence on launching rockets with no controlled reentry has angered U.S. space experts.
“Spacefaring nations must minimize the risks to people and property on Earth of reentries of space objects and maximize transparency regarding those operations,” NASA Administrator Bill Nelson wrote in a statement after the 2021 Long March 5B crash landing. “It is clear that China is failing to meet responsible standards regarding their space debris.”