China has once again decided to let a huge rocket stage fall to Earth on its own.
The decision, the third time the country has chosen not to control the disposal of the first stage of the Long March 5B rocket, puts China under scrutiny by space debris trackers once again after similar uncontrolled falls in 2020 and 2021.
Jonathan McDowell, an experienced tracker of these events at the Harvard-Smithsonian Center for Astrophysics, said US Space Command orbital data shows the 21-ton stage is floating on its own.
“The inert… main stage remains in orbit and has not been actively deorbited,” McDowell wrote. (will open in a new tab) on Twitter. McDowell added (will open in a new tab) that, compared to U.S. launch service providers, Americans “are pretty good at disposing of upper stages, and China is worse on average.”
On the subject: Chinese astronauts Shenzhou-12 sent stunning pictures of the Earth (photo)
The U.S. military has yet to issue warnings on Twitter, either through Space Command or through the 18th Space Defense Squadron, which monitors re-entries. The Aerospace Corporation, which usually provides information about large man-made vehicles re-entering the atmosphere, did not discuss the issue on social media.
Generally speaking, the risk of casualties from falling rocket stages is negligible, but the body of the Long March 5B rocket is especially large.
China launched the Wentian space station module on Sunday (July 24) at 2:25 am EST (0625 GMT or 2:25 pm Beijing time). Wentian docked safely with the Tiangong space station as planned.
(Image credit: CCTV)
A recent study in the journal Nature Astronomy points out that the practice of uncontrolled fall of huge stages to Earth creates an “unnecessary risk” and that China is not alone in this practice, despite international recommendations to prevent the fall of space debris.
The United States and most major international space agencies have practices that govern how to deal with the risk associated with rocket stages. The US government, for example, regulates its falls in accordance with Standard Orbital Debris Mitigation Practice. (will open in a new tab).
Practice calls for the risk of casualties from a missile reentry to be below a threshold of 1 in 10,000, but the article notes that this is not always met. The Air Force waived requirements for 37 of 66 launches between 2011 and 2018 “on the grounds that it would be too expensive to replace non-compliant missiles with appropriate ones,” the article says.
(Image credit: ULA)
Between 2008 and 2018, NASA waived these loss requirements seven times, including the launch of Atlas V in 2015 on the Magnetospheric Multiscale Mission, which had a 1 in 600 risk of accidents, the article says. The authors said it was important to keep this in mind as both the Biden administration and NASA have condemned China’s actions in recent years.
“There is no international consensus on an acceptable level of risk, and other space nations, including the US, are making similar choices regarding uncontrolled reentries,” the authors write. The newspaper was headed by Canadian political scientist Michael Byers of the University of British Columbia.
Because most unguided rocket bodies are launched near the equator, cities in the Global South appear to bear a disproportionate risk. The authors say that at latitudes including Jakarta (Indonesia), Dhaka (Bangladesh), Mexico City, Bogota (Columbia) and Lagos (Nigeria), the risk of a missile reentry is three times higher than in Washington, DC, New York. Beijing and Moscow.
The authors add that national governments whose populations are “at disproportionate risk due to uncontrolled rocket bodies” should call for negotiations, non-binding resolutions or treaties to “create meaningful consequences for non-compliance and thus eliminate risks for all.”
China, however, mostly operates in space on its own, and NASA is not allowed to “engage in any bilateral activity with China or Chinese companies,” according to the agency. (will open in a new tab). The country has also defended its practice of uncontrolled re-entries: China’s foreign ministry has said in the past that the likelihood of problems “causing harm on the ground” is extremely low.
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