9 May 2021

Chinese rocket debris splashes down in Indian Ocean

4:12 pm on 9 May 2021

Pieces of a large Chinese rocket have plunged back through the atmosphere over the Indian Ocean this afternoon, splashing down north of the Maldives.

The Long March-5B Y2 rocket, carrying the Tianhe module, blasts off from the Wenchang Spacecraft Launch Site in south China's Hainan Province on 29 April, 2021.

Photo: Xinhua News Agency

The descent of the Long March 5B rocket had been labelled an uncontrolled re-entry by the US military, and was being tracked by US Space Command.

It entered the atmosphere at 2.14pm (NZT).

Coordinates provided by the China Manned Space Engineering Office put the point of impact in the sea somewhere south-west of India and Sri Lanka.

Earlier, China's foreign ministry said most of the rocket debris was expected to burn up on re-entry, and it was highly unlikely to cause any harm.

The probability of a ground impact in a populated area was "low", the EUSST said on its website, but it noted the uncontrolled nature of the object made predictions uncertain.

Another organisation tracking the rocket pieces said it could touch down in the Tasman Sea, between New Zeland and Australia; Re-entry and debris experts at Aerospace Corporation, a US government funded research and development centre predicted the re-entry for 3.26pm NZ time Sunday.

However, even a tiny variation in the entry time could mean the rocket actually enters over South America or Africa.

The Long March 5B rocket lifted off from China's Hainan island on 29 April with the unmanned Tianhe module, which contains what will become living quarters on a permanent Chinese space station. There are 10 more missions planned to complete the station.

Long March 5B rockets are key to China's immediate space ambitions, with plans to use them for delivery of the modules and crew of the space station, to launches of exploratory probes to the Moon and even Mars.

The Long March launched last week was the second deployment of the 5B variant since its maiden flight in May last year.

Harvard-based astrophysicist Jonathan McDowell previously told Reuters there is a chance that pieces of the rocket could come down over land, perhaps in a populated area, as in May 2020, when pieces from the first Long March 5B rained down on the Ivory Coast. It was reported to have damaged several buildings, though no injuries were recorded.

Debris from Chinese rocket launches is not uncommon within China. In late April, authorities in the city of Shiyan, in Hubei Province, issued a notice to people in the surrounding county to prepare for evacuation as parts were expected to land in the area.

"The Long March 5B re-entry is unusual because during launch, the first stage of the rocket reached orbital velocity, instead of falling down-range as is common practice," the Aerospace Corporation said in a blog post.

"The empty rocket body is now in an elliptical orbit around Earth, where it is being dragged toward an uncontrolled re-entry."

The empty core stage has been losing altitude since last week, but the speed of its orbital decay remains uncertain, due to unpredictable atmospheric variables.

It is one of the largest pieces of space debris to return to Earth, with experts estimating its dry mass to be around 18 to 22 tonnes.

The core stage of the first Long March 5B that returned to Earth last year weighed nearly 20 tonnes, surpassed only by debris from the Columbia space shuttle in 2003, the Soviet Union's Salyut 7 space station in 1991, and NASA's Skylab in 1979.

-Reuters/ RNZ

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