Beijing says uncontrolled reentry of rocket debris poses little risk to anyone on the ground.
Debris from a large Chinese rocket is expected to blast through the atmosphere this weekend in an uncontrolled re-entry that Beijing says it is following closely but poses little risk to anyone on Earth.
The Long March 5B rocket lifted off on Sunday to deliver a laboratory module to China’s new space station under construction in orbit, marking the third flight of China’s most powerful rocket since its inaugural launch in 2020.
As it did during its first two flights, the entire main stage of the rocket, which is 30 meters long and weighs 22 tons (48,500 pounds), has already reached a low orbit and is expected to return to Earth once atmospheric friction. drags it down, according to US experts.
Ultimately, the rocket body will disintegrate as it plunges through the atmosphere, but it is large enough that numerous pieces are likely to survive a fiery reentry in the shower debris over an area of about 2,000 km ( 1,240 miles) long by about 70 km (44 miles) wide. , independent U.S.-based analysts said on Wednesday.
The likely location of the debris field is impossible to determine in advance, although experts will be able to narrow down the potential impact zone closer to re-entry in the coming days.
Re-entry of the latest available tracking data will occur at 00:24 GMT on Sunday, roughly 16 hours, according to Aerospace Corp, a nonprofit government-funded research center near Los Angeles.
“fairly low” risk
The overall risk to people and property on the ground is quite low, given that 75 percent of the Earth’s surface in the potential path of the debris is water, desert or jungle, aerospace analyst Ted Muelhaupt told the journalists at a press conference.
However, there is a chance that pieces of the rocket could fall on a populated area, as they did in May 2020 when fragments of another Chinese Long March 5B landed in Ivory Coast, damaging several buildings in that nation of West Africa, although there were no injuries. were reported, Muelhaupt said.
By contrast, he said, the United States and most other spacefaring nations generally have the additional expense of designing their rockets to avoid large uncontrolled entries, an imperative largely observed since large chunks of the Skylab space station of NASA fell from orbit per year. 1979 and landed in Australia.
Overall, the odds of someone being injured or killed this weekend by falling rocket fragments range from one in 1,000 to one in 230, well above the internationally accepted casualty risk threshold of ‘one in 10,000,’ he told reporters.
But the risk it poses to any individual is much smaller, of the order of six possibilities for every 10 trillion. By comparison, he said, the odds of being struck by lightning are about 80,000 times greater.
Chinese Foreign Ministry spokesman Zhao Lijian said the likelihood of the debris causing damage to aviation or people and property on the ground is very low. He said most of the rocket’s components would be destroyed on reentry.
Last year, NASA and others accused China of being opaque after the Beijing government remained silent on the estimated trajectory of debris or the re-entry window for its final Long March rocket flight in May 2021.
The wreckage of that flight ended up landing harmlessly in the Indian Ocean.
Hours after Zhao spoke on Wednesday, the China Manned Space Agency (CMSA) gave the approximate position of its latest rocket in a rare public statement. At 16:00 (08:00 GMT), the agency said the rocket was circling the globe in an elliptical orbit that was 263.2 km (163.5 miles) high at its most distant and 176.6 km (109.7 miles) high at its closest point.
CMSA did not provide estimated re-entry details on Wednesday.