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China launches Ventian space station module with giant rocket

At 2:22 pm Beijing time, another large Chinese rocket was launched into space and once again where and when it will land, no one knows.

It will be a replay of two earlier launches of the same rocket, the Long March 5B, which is one of the largest currently in use. For about a week after launch, space debris watchers will keep an eye on the world’s 10-story, 23-ton rocket booster as blows of air friction slowly pull it back down.

The probability that it will strike anyone on Earth is low, but much higher than is accepted by many space experts.

The powerful rocket was specifically designed to launch pieces to China’s Tiangong space station. The latest mission raised VENTIAN, a laboratory module that will expand the station’s scientific research capabilities. It will also add three more places for astronauts to sleep and one more airlock for them to do spacewalks.

Completing and operating the space station has been described in state media broadcasts as critical to China’s national reputation. But the country has done some damage to its reputation during the rocket’s previous flights.

After the first Long March 5B launch in 2020, the booster re-entered West Africa, with debris causing damage but no injuries to Ivory Coast villages.

The booster from the second launch, in 2021, disintegrated harmlessly in the Indian Ocean near the Maldives. Nevertheless, NASA Administrator Bill Nelson issued a statement criticizing the Chinese. “It is clear that China has failed to meet responsible standards with respect to its space debris,” he said.

China dismissed that criticism with much fanfare. Hua Chunying, a senior foreign ministry spokeswoman, accused the United States of “propaganda”.

“The United States and some other countries have been excited about the debris landing of the Chinese rocket for the past few days,” Ms Hua said. “To date, there has been no damage from the landing debris. I have seen reports that since the launch of the first manned satellite 60 years ago, there has not been a single incident where a piece of debris hit anyone. The probability is said to be less than one in a billion.”

China’s space agencies did not respond to a request for an interview about the upcoming launch.

Namrata Goswani, author of “Scramble for the Skies: The Great Power Competition to Control the Resources of Outer Space,” said space has a great reputation for the Chinese government, which views each major launch as an accumulation of space power.

Dr. Goswani said that China has overtaken Russia in its space program. “China is ahead of the Russian space program in terms of its lunar and Mars program as well as military space organization,” she said.

On a sunny and warm morning, crowds of space fans from China dispersed on the beach near the rocket launch area on Hainan Island in the country’s south. Others climbed onto the roofs of hotels along the beach.

Zhang Jinghi, 26, set up her camera on the roof of a hotel with about 30 others on Sunday morning.

It was his 19th trip to “chase the rocket”, he said. He had made his hotel reservation four months back.

“There are more people than ever before,” she said.

Ms. Zhang referred to the rocket by the nickname used by aficionados: “Fat Five.” “When it is launched there will be a small earthquake,” she said.

China has landed a rover on the far side of the Moon, collected lunar material and brought it back to Earth for scientific study, and landed and operated a rover on Mars. The United States is the only other country to achieve this final feat.

“China has not and will not do anything that the US has not already done in space,” said Joan Johnson-Fries, a professor at the US Naval War College and former chair of the Department of National Security Affairs. “But it is reaching technological parity, which is of great concern to the US”

She compared the Chinese space program to the American hare as a tortoiseshell, “although the tortoise has grown significantly in recent years.”

As of this April, China had completed a total of six missions to build the space station. Three crews of astronauts have lived on the station, including the trio that received the Ventian module this week.

About 15 minutes after launch, the rocket booster successfully placed the Ventian spacecraft on its intended orbital path. It is to rendezvous with the Tianhe Space Station module approximately 13 hours after liftoff. The Chinese space agency has given no indication that it has made any changes to the booster.

“It’s going to be the same story,” said Jonathan McDowell, an astrophysicist at the Center for Astrophysics in Cambridge, Mass., which tracks the coming and going of objects in space. “It’s possible that the rocket designers could have made some minor changes to the rocket that would let them move off the stage. But I don’t expect that.”

If the design of the rocket has not changed, none of the thrusters will guide its descent, and the booster’s engine cannot be restarted. The final rain of debris, a few tons of metal expected to survive all the way to the surface, could occur anywhere along the booster’s path, which heads north to 41.5 degrees north latitude and south to 41.5 degrees south latitude.

This means there would be no threat to Chicago or Rome, both of which lie north of the orbital trajectory, but Los Angeles, New York, Cairo and Sydney, Australia are among the cities the booster will travel.

The science of predicting where a tumbling rocket stage is going to fall is difficult. Earth’s atmosphere inflates and deflates depending on how intensely the Sun is shining on a particular day, and this phenomenon speeds up or slows the rate of fall. If the calculations hold off by half an hour, the falling debris has already traveled a third of the way around the world.

By design, the center booster stage of the Long March 5B will push the Ventian module, which is more than 50 feet tall, all the way to orbit. That is, the booster will also reach orbit.

This is different from most rockets, where the lower stage is usually returned to Earth shortly after launch. The upper stages that reach orbit usually re-fire the engines after dropping their payloads, guiding them towards re-entry into an empty area like the middle of an ocean.

The malfunction sometimes causes uncontrolled re-entry, such as the second stage of a SpaceX rocket that dropped over Washington state in 2021. But the Falcon 9 stage was smaller, about four tons, and less likely to cause damage or injury.

The United States and NASA were not always as careful when returning large objects into the atmosphere as they are now.

Skylab, the first US space station, fell to Earth in 1979, with large fragments hitting Western Australia. (NASA never paid a $400 fine for litter.)

NASA did not even plan to dispose of its Upper Atmosphere Research Satellite, or UARS, after that mission ended in 2005. Six years later, the defunct satellite, the size of a city bus, was headed for an uncontrolled resale. -admittedly, NASA calculated a 1-in-3,200 chance that someone could be injured. Eventually it fell into the Pacific Ocean.

Typically 20 percent to 40 percent of a rocket or satellite will survive re-entry, said Ted Muelhaupt, a debris expert at the Aerospace Corporation, a nonprofit funded largely by the federal government that conducts research and analysis.

This would suggest that 10,000 pounds to 20,000 pounds of the Long March 5B booster could hit Earth’s surface.

Mr Muelhaupt said the United States and some other countries avoid uncontrolled re-entry of space debris if the chance of injury to someone on the ground is more than 1 in 10,000.

To date, there are no known cases where someone has been hurt by falling man-made space debris.

“That number 1 in 10,000 is somewhat arbitrary,” said Mr Muelhaupt. “It has been widely accepted, and recently there has been concern that when too many objects re-enter, they add up to the point where someone is going to get hurt.”

If the risk is high, “dumping them in the ocean is fairly common,” said Marlon Sorge, executive director of the Aerospace Corporation’s Center for Orbital and Re-entry Debris Studies. “That way, you know you’re not going to kill anyone.”

Mr Muelhaupt said that without details of the design of the Chinese rocket, it would not be possible to calculate the risk estimate. But “I’m pretty confident it’s well above the risk threshold of one in 10,000”, he said. “Well above the threshold.”

The Long March 5B booster is about three times larger than the UARS. A rough estimate would be that this is three times the 1-in-3,200 risk estimated by NASA for UARS, probably more.

“It’s three UARS in some sense,” Dr. McDowell said. The chances of this booster injuring someone, he said, “could be as high as one in a few hundred.”

During a prelaunch broadcast on CGTN, a Chinese state media outlet, Xu Yansong, a former official of the National Space Administration of China, referred to the 2020 event in Ivory Coast. Since then, he said, “we have improved our technologies”. To bring down the rocket stage in an uninhabited area, But he did not give any specific information.

The same chain of events may soon resume.

In October, China will launch a second laboratory module called Mengtian into orbit to complete the assembly of the Tiangong. It will also fly on another Long March 5B rocket.

Lee You contributed to the research.

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