Debris of an uncontrolled Chinese missile lands in Southeast Asian seas

Large Chinese missile debris re-entered Earth’s atmosphere over the Indian Ocean at 12:45 p.m. ET, according to US space command.

in update Posted on social network WeiboMost of the debris was burnt up when it re-entered over the Sulu Sea, a body of water located between the island of Borneo and the Philippines, China’s manned space agency said.

The possibility, however slight, that debris from the missile could hit a populated area has prompted people around the world to trace its path for days.

NASA Administrator Bill Nelson issued a reprimand Saturday, saying that China “did not share specific trajectory information where the Long March 5B rocket landed.” He added that all countries should “share this type of information in advance to allow reliable predictions of potential wreck impact risks, especially for heavy vehicles, such as the Long March 5B, which have a significant risk of loss of life and property.”

The rocket that Mr. Nelson referred to in his statement launched last Sunday, carries in orbit a laboratory module that has been added to the Chinese space station, Tiangong. Usually, the large stages of booster rockets immediately fall to the ground after disposing of them. But the 23-ton core stage of Long March 5B accompanied the space station portion all the way to orbit.

Due to the friction caused by the friction of the missile with the air in the upper part of the atmosphere, it quickly began to lose altitude, causing the so-called “uncontrolled return” to Earth. In recent days, space observers have predicted possible reentries over much of the planet. On the last day, the prediction became more accurate, but until then forecasters were not sure whether it would land over the Indian Ocean, off Mexico or in the Atlantic.

People in Sarawak, a province of Malaysia on the island of Borneo, have reported seeing the wreckage of the rocket on social media, with many believing the fireworks at first were meteor shower or a comet.

This was the third flight of the Long March 5B missile, China’s largest. The country’s space program needed such a large and powerful vehicle to carry parts into orbit to assemble its space station.

On its first test flight of 2020, it lifted a reusable astronaut capsule with no crew on board into orbit. That shell landed on villages in Ivory Coast, West Africa, causing some property damage but no injuries.

The second flight carried the Tianhe, the main unit of the new space station Tiangong, last year and splashed into the Indian Ocean. This launched the Wentian Additive, the laboratory unit.

The Long March 5B contained multiple pieces. Four side boosters fell shortly after launch, crashing harmlessly into the Pacific Ocean. (Disposing of used and unwanted missile parts in the ocean is a common practice.) But the primary boost stage – a 10-story cylinder weighing 23 tons empty – carried the Wentian unit into orbit.

The laboratory installation advances the second outpost into orbit where humanity will be able to conduct scientific research in a microgravity environment.

China plans to operate the new Tiangong plant for at least a decade, inviting other countries to participate. Tiangong is smaller than the old International Space Station, which will be retired in 2030 under current NASA plans, although Russia has given mixed signals about how long the engagement will last.

In recent decades, rocket stages that reach orbit typically fire the engine again after their payloads are released so that they withdraw from orbit, targeting an uninhabited area such as the middle of the ocean.

Typically 20 to 40 percent of a rocket or satellite survive re-entry, indicating that 10,000 to 20,000 pounds of Chinese boosters will reach Earth’s surface.

Another lab module is scheduled to be launched using the same rocket in October, to complete construction of the space station. A final mission for the rocket is planned for 2023, to carry an orbiting space telescope.

Experts say the missile’s designers have alternatives to his approach. They could have stopped firing the booster before reaching orbit. And then you will immediately return to land in the Pacific Ocean. But then they had to augment the thrusters on the space station module to take it the rest of the way into orbit.

Jonathan McDowell, an astrophysicist at the Center for Astrophysics in Cambridge, Massachusetts, who tracks space debris, suggested that the Chinese might have been able to use a trick similar to what NASA engineers did more than 40 years ago with their Saturn 1B rocket. The Saturn 1B’s second stage was large and, like the Long March 5B booster, had no re-entry control thrusters.

“They’ve done something smart in terms of venting the fuel,” said Dr. McDowell. “They didn’t actually have a rocket ignition engine, but they vented the fuel in such a way as to lower the perihelion point in the atmosphere.”

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