Danger from above: Space debris poses major risk of falling into busy airspace

On November 4, 2022, a 20-tonne rocket body from a Long March 5B mission reentered Earth’s atmosphere over the Pacific Ocean. The reentry was entirely uncontrolled, occurring randomly rather than by design. Just hours before, European aviation authorities had prepared for a potential impact over southern Europe, forcing Spain and France to close parts of their airspace.

The decision to close airspace wasn’t taken lightly. European aviation regulators issued urgent notices to warn pilots and airlines of the potential danger. As a result, 645 flights were delayed by an average of 29 minutes. Some planes already in flight had to change course, turn back, or divert to alternative airports.

Meanwhile, neighboring countries like Portugal, Italy, and Greece, which were also under the rocket’s projected path, chose to keep their airspace open. This led to an influx of diverted flights, causing congestion and operational risks.

This marked the first time in history that airspace was shut down due to an uncontrolled rocket reentry. While previous reentries had led to safety bulletins, no country had ever taken such drastic action. The event underscored a growing problem: as space launches increase, so do the risks posed by debris reentering Earth’s atmosphere.

Though the likelihood of space debris striking an aircraft remains small, the potential consequences are severe. Air travel has more than doubled since 2000, and satellites and rocket bodies left in orbit have also increased dramatically. More than 2,300 abandoned rocket bodies are currently circling Earth, waiting to reenter in unpredictable ways. In 2023 alone, 128 rocket bodies were left in orbit after launches, with uncontrolled reentries happening almost weekly.

When space junk falls back to Earth, most of it burns up in the atmosphere. However, larger objects, such as discarded rocket stages, often survive the descent, creating a real hazard. Even tiny debris can be dangerous when it collides with an aircraft traveling at high speed.

A piece as small as one gram could cause serious damage if it struck an aircraft windshield or was ingested by an engine. Nine-gram steel projectiles have been shown to penetrate fuselages, and anything weighing more than 300 grams could result in total aircraft loss.

Aerospace experts have analyzed the risks and found unsettling results. In 2021, researchers estimated that the chance of a fatal aircraft collision with falling debris was 1 in 100,000. If future rocket launches continue at their current pace, this risk could rise to 7 in 10,000 by 2035. While this may still seem low, the number of passengers onboard commercial aircraft means that even a single strike could lead to mass casualties.

Historical incidents have demonstrated how widespread debris can be after a space disaster. In 2003, when the Space Shuttle Columbia disintegrated upon reentry, its debris rained down across a massive area for over two hours. Had commercial flights been in the affected region, they would have faced a significant danger, with estimated aircraft risk ranging from 0.3% to 10%.

For aviation authorities, space debris presents a difficult dilemma. Allowing flights to continue under a reentry path carries a small but real risk of catastrophe. On the other hand, closing airspace disrupts flight schedules, burdens airlines with unexpected costs, and frustrates passengers.

Each delayed or diverted flight results in increased fuel expenses, crew rescheduling complications, and financial losses for airlines. In severe cases, airspace shutdowns could cost the industry tens of millions of dollars. However, these costs are not borne by space agencies or companies responsible for launching rockets. Instead, airlines, passengers, and taxpayers absorb the financial burden.

This has led experts to argue that the space industry is unfairly shifting its risks onto the aviation sector. According to legal scholars, under international law, the country that launches a satellite or rocket could be held liable not just for physical damage but also for economic losses resulting from precautionary airspace closures.

The problem isn’t just theoretical. A recent study from the University of British Columbia and published in the journal Scientific Reports found a 26% annual probability that space debris will reenter Earth’s atmosphere over a busy flight corridor. In regions with moderate air traffic, such as the airspace between Vancouver and Seattle, there’s a 26% chance per year of a rocket reentry occurring overhead. In areas with even lower traffic, such as southern Europe, the probability jumps to 75% per year.

Space industry growth is only making the situation worse. In 2024, a record-breaking 258 rockets were launched into space. More than 120 of these missions left uncontrolled debris in orbit. Meanwhile, global air travel continues to expand, with passenger numbers projected to increase by nearly 7% in 2025.

Aviation regulators currently have only two choices: take the risk and allow flights to continue, or close airspace and deal with the consequences. But experts argue that this shouldn’t be a decision for aviation authorities at all. Instead, the space industry must take responsibility.

"Uncontrolled rocket body reentries are a design choice, not a necessity," said Dr. Aaron Boley, a professor of physics and astronomy. "The space industry is effectively exporting its risk to airlines and passengers."

There is a straightforward solution: rockets could be designed to reenter Earth’s atmosphere in a controlled manner, steering their descent into the ocean rather than populated areas or busy flight paths. However, this approach comes with additional costs, which most companies are reluctant to absorb unless regulations force them to do so.

"Countries and companies that launch satellites won’t spend the money to improve their rocket designs unless all of them are required to do so," said Dr. Michael Byers, a professor of political science. "So, we need governments to come together and adopt some new standards."

Without coordinated international action, the problem will only grow. More space launches mean more abandoned rocket bodies, more debris, and a higher probability of dangerous reentries. As space becomes increasingly crowded, the need for stricter regulations becomes urgent.

If no action is taken, uncontrolled rocket debris will continue to rain down unpredictably, forcing aviation authorities into impossible decisions. In a world where both space travel and commercial aviation are expanding, ensuring their coexistence without endangering lives will require global cooperation and responsible policies.

Note: Materials provided above by The Brighter Side of News. Content may be edited for style and length.

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