The increasing presence of space junk in Earth’s orbit is posing an escalating threat to air travel, with new research highlighting the risks associated with uncontrolled rocket debris re-entering the atmosphere.
A recent study from the University of British Columbia (UBC) estimates a 26% annual probability that rocket debris will descend into busy flight paths, creating potential disruptions for airlines and passengers alike.
While the likelihood of space junk striking an aircraft remains low, the economic and logistical impact of airspace closures due to falling debris is significant.
Authorities have already had to shut down airspace due to uncontrolled rocket re-entries, disrupting commercial flights and causing financial burdens on airlines and travellers.
Rocket launches and flights on the rise
As the global space industry continues its rapid expansion, so too does the frequency of rocket launches.
In 2024 alone, there were 258 successful launches, contributing to a record-breaking 120 uncontrolled rocket debris re-entries.
With more than 2,300 spent rocket bodies still orbiting Earth, the issue of uncontrolled re-entry is only expected to grow.
At the same time, air travel is also on the rise. The International Air Transport Association predicts air passenger numbers will increase by nearly 7% in 2025, leading to even more aircraft in the skies and a higher likelihood of space debris intersecting with commercial airspace.
The impact of space debris on aviation safety
Researchers at UBC analysed air traffic data and found that on the busiest day of 2023, Denver, Colorado, had the highest air traffic density, with one aircraft for every 18 km².
Using this as a reference point, they calculated the probability of rocket debris re-entering over high-traffic airspace.
Their findings were concerning:
- A 26% annual chance of space junk re-entering over airspace similar in traffic density to the Vancouver-Seattle corridor.
- A 75% global chance of debris re-entering over areas with air traffic density comparable to southern Europe, where airspace was temporarily closed in 2022 due to falling rocket debris.
The estimated annual probability of space debris actually colliding with an aircraft is 1 in 430,000 – a low but non-negligible risk that aviation authorities cannot ignore.
Space industry shifting risk to airlines
The core issue lies in how modern rockets are designed. Many rocket stages that propel satellites into orbit remain in space and eventually fall back to Earth in an uncontrolled manner.
This means aviation authorities are forced to either reroute flights, close airspace or take the risk of allowing flights to continue under uncertain conditions.
Experts argue that uncontrolled rocket body re-entry is an avoidable design flaw, not an inevitability.
The space industry could implement safer designs, such as rockets capable of controlled re-entry into designated ocean zones after deployment.
However, such changes require global cooperation and regulation, as no single country or company wants to bear the cost alone.
A call for international action
UBC researchers stress that governments must set international standards to mandate controlled re-entries for rocket stages.
Without such regulations, private companies and nations launching satellites will have little incentive to adopt safer designs.
As space activity continues to grow, failure to address the space junk crisis could result in more frequent airspace disruptions, increased costs for airlines, and heightened risks for passengers.
With both the aviation and space industries at a critical crossroads, policymakers must act swiftly to ensure that the skies remain safe – not just for aircraft but for everyone who relies on them.
