Beijing says the uncontrolled re-entry of rocket debris poses little risk to anyone on the ground.
The remains of a large Chinese rocket are expected to smash through the atmosphere this weekend in an uncontrolled re-entry that Beijing says is watching 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 maiden launch in 2020.
As happened on its first two flights, the rocket’s entire main stage – which is 100 feet (30 meters) long and weighs 22 tons (48,500 pounds) – has already reached the low orbit and should fall back to Earth once atmospheric friction drags it down, US experts say.
Ultimately, the rocket body will disintegrate as it plummets through the atmosphere, but it’s large enough that many pieces will likely survive a fiery re-entry to rain debris down on an area of about 2,000 km ( 1,240 miles) long by about 70 km (44 miles) wide. , independent analysts based in the United States said on Wednesday.
The likely location of the debris field is impossible to determine in advance, although experts are able to narrow down the potential impact area closer to re-entry in the coming days.
The last available re-entry of tracking data projects will be around 12:24 a.m. GMT on Sunday, roughly 4 p.m., according to Aerospace Corp, a government-funded nonprofit research center near Los Angeles.
“Fairly low” risk
The overall risk to people and property on the ground is quite low, given that 75% of the Earth’s surface in the potential debris path is water, desert or jungle, the aerospace analyst said. Ted Muelhaupt to reporters at a press briefing.
Nevertheless, it is possible for pieces of the rocket to fall over a populated area, as they did in May 2020 when fragments from another Chinese Long March 5B landed in Ivory Coast, damaging several buildings in the West African country, but no injuries. have been reported, Muelhaupt said.
By contrast, he said, the United States and most other space nations typically go to the extra expense of designing their rockets to avoid large, uncontrolled re-entries — a widely observed imperative since large chunks of the NASA Skylab space station fell from orbit in 1979 and landed in Australia.
Overall, the odds of someone being injured or killed this weekend due to falling rocket pieces range from 1 in 1,000 to 1 in 230, well above the accident risk threshold. internationally accepted 1 in 10,000, he told reporters.
But the risk posed to a single individual is much lower, around six chances per 10,000 billion. By comparison, he says, the odds of being struck by lightning are about 80,000 times higher.
Chinese Foreign Ministry spokesman Zhao Lijian said the likelihood of debris causing damage to aircraft or to people and property on the ground was very low. He said most of the rocket’s components would be destroyed during re-entry.
Last year, NASA and others accused China of being opaque after the government in Beijing remained silent on the estimated trajectory of debris or the re-entry window for its final Long March rocket flight in May. 2021.
Debris from that flight ended up landing safely in the Indian Ocean.
Hours after Zhao’s speech on Wednesday, the China Manned Space Agency (CMSA) gave the approximate position of its latest rocket in a rare public statement. At 4 p.m. (0800 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 furthest point and 176.6 km ( 109.7 miles) high at its closest point.
No details on the estimated re-entry were given by CMSA on Wednesday.