The booster of a large Chinese rocket plummeted on November 4 in an uncontrolled re-entry, breaking up over the south-central Pacific Ocean. This rocket booster, coming in at over 98 feet long and weighing up to 25 tons, helped launch China’s on October 31, as the reports. The booster’s fall forced Spain to shut down a portion of its airspace to avoid a possible collision, and the closure hundreds of flights.

The European Union Space Surveillance and Tracking (EUSST) agency tracked the Chinese booster as it tumbled back to Earth’s atmosphere, calling it “one of the largest pieces of debris re-entering in the near past,” per the .

This is the fourth of sizable debris from a launch since China began construction of the Tiangong space station in 2020. Since then, China has let fragments of the Long March 5B re-enter the atmosphere without having control over their descent. There’ve been no injuries or deaths during these rogue re-entries, but there has been property damage in places such as the Ivory Coast in Africa where several buildings were hit by the space debris.

As you can imagine, there’s also been a great deal of nervous anticipation and scrambling efforts to track fragments that break away from China’s biggest rocket, the Long March 5B (CZ-5B), which has been carrying material needed to build the Chinese “” space station. China has come under a great deal of criticism for allowing these dangerous re-entries, but a spokesperson for the Chinese foreign ministry said this is a common practice and added that:

“It is understood that [this] type of rocket … uses special technology designed so the vast majority of components … will be destroyed by ablation during re-entry into the atmosphere, and the probability of causing harm to aviation activities and the ground is extremely low,” said Zhao.

Even if the probability of causing harm is “extremely low” it’s not exactly zero, and that’s why the international community is scrutinizing China’s launch practices. Experts and analysts are distinguishing China’s launches from recent missions undertaken by the U.S., which pay closer attention to the trajectory discarded boosters will eventually travel along.

These descents are not controlled, per se, but there is deliberate care taken to monitor and estimate (for the sake of safety) when and where debris will fall. Most times, NASA plots a re-entry over the ocean. One consultant with the , a nonprofit group in the U.S. funded by the federal government, pointed out that “we, the world, don’t deliberately launch things this big intending them to fall wherever,” as the reports.

China says that such re-entries are an international practice, referring to the core stage of the rocket, which only breaks away after the rocket has delivered its payload — unlike the Long March 5B rocket’s smaller side boosters that break off harmlessly into the ocean shortly after launch. According to , adding more equipment to the Long March 5B boosters, such as control modules, would use up the rocket’s payload capacity. The Chinese space agency is presumably trying to maximize how much cargo can be hauled into orbit, and as a result, is opting to let the boosters fall where they may.