The 23-tonne rocket booster of a Chinese Long March 5B rocket re-entered Earth’s atmosphere at 1645 GMT on Saturday, with remains crashing into the Sulu Sea between Malaysia and The Philippines.
Video images of the structure burning-up as it passed through the atmosphere was captured by locals in Malaysia (though at first incorrectly observing it as a meteor).
Long March 5B core return criticised by NASA
This is the third time a Long March 5B core stage has returned to Earth in an uncontrolled manner.
Previous occasions include in 2020 when fragments landed in villages in Cote d’Ivoire and last year’s burn-up over the Indian Ocean.
Although accurate predictions of stage re-entry borders on impossible owing to a range of factors including atmospheric drag and object orientation and behaviour in orbit, ‘ground tracks’ – effectively re-entry pathways – were predicted in the days leading up to the core’s eventual return.
But China’s space authority did not offer an estimate for the re-entry, prompting criticism from NASA Administrator Senator Bill Nelson.
“The People’s Republic of China did not share specific trajectory information as their Long March 5B rocket fell back to Earth,” Nelson said on Sunday.
“All spacefaring nations should follow established best practices, and do their part to share this type of information in advance to allow reliable predictions of potential debris impact risk, especially for heavy-lift vehicles, like the Long March 5B, which carry a significant risk of loss of life and property.
“Doing so is critical to the responsible use of space and to ensure the safety of people here on Earth.”
China’s space agency reported the eventual debris landing area at 119.0 degrees East and 9.1 degrees North, about 60 kilometres east of the Philippine island Palawan.
Though there are no reports of debris landing on populated areas as with the 2020 re-entry, recent research suggests there is a 10% chance that someone on Earth will be fatally struck by space debris within the next decade.
While smaller space debris undergoes uncontrolled re-entry, spacefaring organisations usually build large objects (like the 5B core stage) to reignite their engines in orbit for a safe return.
That could be a controlled landing in the case of the SpaceX Falcon rocket, or a guided crash into sea or land away from human populations.
Only six objects over 20 tonnes have undergone uncontrolled re-entry since the beginning of space travel.
They include NASA’s Skylab in 1979, Russia’s Mir space station (2001), NASA’s Columbia space shuttle (2003) which tragically broke-up in its controlled re-entry attempt, and the core stages from China’s three Long March 5B’s launches.
Matthew Agius is a science writer for Cosmos Magazine.
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