Debris from Chinese rocket falls back to Earth

Chinese missile debris has crashed to earth over the Indian and Pacific oceans, US and Chinese authorities say.

China’s space agency said most of the remains of Long March 5 burned up in the atmosphere, and identified the Sulu Sea in the Pacific Ocean as the site of re-entry.

In the past, space experts have said that the probability of the rocket landing in a populated area was extremely low.

The uncontrolled return of the rocket’s core stage has raised questions about responsibility for space debris.

There have previously been calls from Nasa to the Chinese space agency to design rockets to disintegrate into smaller pieces on re-entry, as is the international norm.

In a tweet, the US Space Command said Long March 5 “entered over the Indian Ocean at approximately 10:45 a.m. MDT [16:45 GMT] on 7/30”.

It referred its readers to Chinese authorities for more details.

Meanwhile, China’s space agency gave the re-entry coordinates as 119 degrees east longitude and 9.1 degrees north latitude. This corresponds to an area in the Sulu Sea – east of the Philippine island of Palawan in the North Pacific.

Recent rockets bound for China’s unfinished space station, known as Tiangong, have lacked the ability for a controlled re-entry.

The most recent launch was last Sunday, when the Long March 5 rocket carried a laboratory module to the Tiangong Station. The Chinese government said Wednesday that the rocket’s re-entry would pose little risk to anyone on the ground because it would most likely land in the sea.

However, there was a possibility that parts of the rocket could fall over a populated area, as they did in May 2020 when properties in Côte d’Ivoire were damaged.

Before it crashed, the empty rocket body was in an elliptical orbit around Earth where it was dragged towards an uncontrolled re-entry.

Designing objects to disintegrate upon atmospheric reentry is becoming a priority for satellite operators. This is partly done by using materials that have low melting point temperatures, such as aluminium.

In the case of rockets, this can be expensive, as the materials used to house propellants, such as titanium, historically require very high temperatures to burn up. The sheer size of such objects is also a problem, especially in the case of the Long March 5, which weighs over 25 tons.

Long March 5 rocket

Long March 5 rocket before departure in May 2021

The same Long March 5 configuration has launched twice before, once in May 2020 and again in May 2021, with different elements from the Tiangong station.

On both occasions, debris from the rocket’s “core stage” was dumped back on Earth, in Ivory Coast and the Indian Ocean. These followed a prototype that crashed in the Pacific Ocean back in 2018.

None of these incidents caused damage, but drew criticism from a number of space agencies. On Tuesday, the Chinese state-run Global Times newspaper accused Western media of a US-led smear campaign against the long March 5.

This latest launch carried the second of three modules for China’s space station. The 17.9 meter Wentian Laboratory Module will be the first of two laboratories to join the station. China began building the space station in April 2021 with the launch of the Tianhe module, the main housing.

China hopes Tiangong will be completed by the end of 2022.

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