A hulking, out-of-control Chinese rocket core is currently pinwheeling around the globe once every 90 minutes, and there’s no telling exactly when — or where — it will come crashing down to Earth in a potentially dangerous re-entry.
The object is a 30-metre tall, 21-tonne leftover from China’s Long March 5B rocket, which carried a piece of its new Tianhe space station into orbit on Apr. 29. The rocket launched its cargo into space before its core tumbled into a chaotic temporary orbit around Earth, where it’s been rapidly circling the planet while slowly falling ever since, SpaceNews reports.
The core, dubbed CZ-5B, was initially expected to make a harmless reentry, but observers say it appears to be falling out of control, making it hard to predict exactly where it will come down. Its path takes it over much of the globe, but projections suggest it could fall as far south as Chile or New Zealand, and as far north as New York State or Ontario.
The booster was travelling at roughly 28,000 kilometres per hour while circling 300 kilometres above the Earth on Tuesday, according to tracking data. At 21 tonnes, experts say it’s large enough to avoid burning up in the atmosphere when it eventually does come down.
“It’s potentially not good,” Jonathan McDowell, an astrophysicist at Harvard University, told The Guardian. He says it will likely fall into the ocean but it could leave a swath of destruction if it falls over land, in what would be the “equivalent of a small plane crash scattered over 100 miles.”
Space agencies typically have plans for disposing of such large pieces of junk, including built-in burners that can knock a core out of orbit when necessary, but that’s not the case with this rocket core. Chinese officials are essentially crossing their fingers and watching, while hoping that it lands in the ocean and not over land.
“What’s bad is that it’s really negligent on China’s part,” McDowell said. “Things more than 10 tonnes, we don’t let them fall out of the sky uncontrolled deliberately.”
The U.S. military and European space officials are among the many groups tracking the core’s descent.
It’s just the second time that China has launched one of these rockets, and the second time that it’s been accused of being careless with the leftovers.
The first Long March 5B rocket was launched on May 5, 2020, and its core also entered temporary orbit for nearly a week. The object eventually came down and crashed near some villages in the Ivory Coast on May 11, in a fall that sparked a fierce rebuke from NASA at the time.
The object was damaged by the heat of entering the atmosphere, but a 12-metre-long pipe reportedly survived the fall along with other bits of debris.
No deaths or injuries were reported from that incident.
Experts are hoping luck will be on everyone’s side when this latest booster falls back to Earth sometime around May 10. McDowell says it will be possible to predict the crash location about six hours before it hits.
At 21 tonnes, the rocket would be one of the largest objects to make an uncontrolled re-entry in the last 30 years. It’s still small in comparison to SkyLab, the 76-tonne NASA station that made a fiery return to Earth in 1979. Most of SkyLab fell into the Indian Ocean, but it also scattered debris across an uninhabited stretch of Australia when it came down.
China’s recent launch is the first of a planned 11 missions to set up China’s Tianhe (Heavenly Harmony) space station by the end of next year. That means there will be more Long March 5B rockets going up — and more coming down — in the months ahead.