China successfully launched the third and final piece of its new Tiangong space station on Monday – and the rocket’s 23-tonne body is returning to Earth somewhere this weekend.
The Mengtian module, which carries science experiments, took off on China’s Long March 5B rocket. As it ascended into space, the rocket’s core stage gave the space station module a final push into Earth orbit before breaking away.
Unlike most modern rocket bodies, which are designed to push themselves into a remote part of the Pacific Ocean, the Long March 5B body fell into its own orbit around Earth.
It’s on track to descend back into the atmosphere — an event called “re-entry” — and fall to Earth on Friday or Saturday morning in the Eastern Time Zone.
No one knows where the rocket body will fall and no one controls it. But space debris is extremely unlikely to hit you.
Forecast: it will rain rocket parts
Experts can only estimate the amount of bodies from the Long March rocket, which is about the size of a 10-story building, that will crash into Earth. Some of it will probably burn up as it passes through the atmosphere, but the rocket body is too big to completely disintegrate.
A rule of thumb is that 20-40% of a large object’s mass will survive its fall through the atmosphere, experts at the Aerospace Corporation previously told Insider.
It’s still too early to say exactly where the middle phase might fall – most likely in pieces. But the Aerospace Corporation tracks the rocket stage and predicts the possible paths it could take to return to Earth.
The area where the debris could fall covers about 88% of the human population, according to these analysts’ calculations. But this population is highly condensed in a few places. Most of the area where debris could rain down is in the open sea or on uninhabited land.
Still, space industry executives have denounced China’s practice of uncontrolled re-entry, saying it poses an unnecessary risk to human life and property.
Estimates will improve in the coming days as the rocket body gets closer to reentry.
Chinese rocket debris continues to crash into Earth
This is the fourth time that a remnant of China’s Long March 5B rocket has threatened human life and property. Each of the three times the rocket was launched – in 2020, 2021 and July 2022 – pieces of its body fell back to Earth.
In May 2020, debris from one of these rockets was discovered near two villages in Côte d’Ivoire, causing material damage. In 2021, China said remnants of the rocket had landed in the Indian Ocean near the Maldives, according to The New York Times.
Earlier this year in July, parts of the rocket’s booster also crashed on Earth, with several likely parts discovered on the Malaysian and Indonesian sides of the island of Borneo, as well as in the ocean near the Philippines.
Most rocket stages collapse upon reigniting their engines shortly after delivering their cargo to orbit, drifting away from populated areas and into the Pacific Ocean. But in the case of the Long March 5B, China did not design the rocket booster for controlled re-entry.
“Rockets are going all the time, and re-entry is very rare,” John Logsdon, the founder of George Washington University’s Space Policy Institute, told Insider in May 2021. as the world waited for the rocket body to fall. “So yeah, I’m a bit confused as to why this is happening.”
“Is it just a willful disregard of international guidelines? Or because it’s a new vehicle it wasn’t properly designed to be able to perform a controlled re-entry? It doesn’t matter,” Logsdon said, adding, “It’s It’s a shame that it puts a lot of people at risk.”
Space debris could kill someone this decade
In a study published in the journal Nature in July, researchers calculated about a 10% chance of debris hitting one or more people over a 10-year period. It’s not just Chinese rockets. Satellites and pieces of unknown debris regularly fall out of orbit.
“If you roll the dice too many times, someone will get lucky,” Jonathan McDowell, a Harvard astronomer who meticulously tracks objects in Earth’s orbit, previously told Insider.
Ted Muelhaupt, a consultant who works on Aerospace Corporation’s re-entry database, previously told Insider that an object weighing at least 1 ton falls from orbit and re-enters the atmosphere on a weekly basis.
The Long March 5B boosters are among the largest objects to retract on Earth, but uncontrolled re-entry is not unique to China. In 1979, NASA’s Skylab space station descended rapidly, scattering debris over Australia. Today, however, controlled re-entry is common practice.
This article was originally published by Business Insider.
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