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Rocket debris from two different orbital missions has come crashing down to Earth in recent weeks, ending up in rural Australia and off the coast of the Philippines, highlighting growing concerns about the potential risks of falling spacecraft parts to people and infrastructure.
Though the chance of any one person being hit by errant space junk is astronomically low, it is not zero. In fact, according to experts, the odds of being injured or killed by space debris is rising in tandem with a rapid uptick in launches conducted around the world every year.
This point was driven home on Saturday when chunks of China’s most powerful rocket, the Long March 5B, streaked across the skies over the Indian Ocean during an uncontrolled reentry into Earth’s atmosphere. The debris broke apart and plummeted into the Sulu Sea, barely missing Palawan Island in the Philippines, with no casualties reported.
Some spectators in Indonesia and Malaysia filmed the fiery return of the spent rocket parts, which had been careening around orbit since China launched a module of its space station into orbit on July 24. While delivering the station laboratory to space, the rocket left its huge 22-ton main booster in orbit, as well.
Most big rocket parts are designed to fall back to Earth, specifically in unpopulated regions, but each of the Long March 5B’s three flights has ended with these uncontrolled reentries—one fell in the Indian Ocean in 2021, and the first may have battered villages in Côte d'Ivoire in 2020.
China is far from the only spacefarer that has played fast and loose with falling rockets from the sky, however. In fact, it’s not the only one this month. Reports are emerging that a huge piece of space junk that might belong to SpaceX, the private space company, smashed into a sheep farm in southeast Australia around July 9. The hunk of metal might have been part of SpaceX’s Crew 1 mission, which delivered astronauts to the International Space Station in 2020 and returned them in 2021, according to Space.com.
SpaceX has not commented on the origin of the debris, but space commentators such as Jonathan McDowell, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics, speculated that it might be part of the unpressurized trunk of SpaceX’s Crew Dragon vehicle, which was ejected from the craft before it reentered in 2021 and carried its crew back to Earth.
The remains of this spacecraft component were projected to fall back to the planet at this time and place last month; locals also reported hearing a loud bang that might have been related to its reentry last month, according to ABC. The incident is reminiscent of the dramatic reentry of NASA’s Skylab space station in 1979, which unexpectedly sprinkled remnants of the orbital habitat across Australia.
If the newly found debris is confirmed to be from the Crew 1 mission, it would be the second time in as many years that a SpaceX rocket part crash-landed on a farm. Last year, a pressure vessel from the company’s Falcon 9 rocket impacted a farm in Washington state, with no injuries reported.
SpaceX rocket parts that are left in space are typically equipped with the ability to perform a controlled reentry over the oceans, but this component didn’t have enough fuel to deorbit as planned.
Well over 100 orbital launches are now performed every year, and that number is expected to rise over the coming decade. As space becomes more crowded with junk parts, uncontrolled reentries will become more common, and the risk of death or injury will grow, even if it remains unlikely. Indeed, a recent study in Nature Astronomy projected that there is a 10 percent chance a person will be killed by falling spacecraft parts this decade.
“Most space launches result in uncontrolled rocket body reentries, creating casualty risks for people on the ground, at sea and in aeroplanes,” according to the study. “These risks have long been treated as negligible, but the number of rocket bodies abandoned in orbit is growing, while rocket bodies from past launches continue to reenter the atmosphere due to gas drag.”
“Those national governments whose populations are being put at risk should demand that major spacefaring states act, together, to mandate controlled rocket reentries, create meaningful consequences for non-compliance and thus eliminate the risks for everyone,” it concluded.