25% Annual Probability of Rocket Debris Intruding on Congested Airspace

Researchers at the University of British Columbia (UBC) have recently released a compelling study that emphasizes the potential hazards posed by re-entering space debris, particularly regarding the aviation sector. The study reveals a startling 26 percent annual chance of uncontrolled space rocket debris re-entering the atmosphere and traversing busy air traffic zones. While the probability of such debris colliding with an aircraft remains exceptionally low, the broader implications of potential disruptions to flights and associated costs for airlines and travelers merit serious attention.

The growing concern regarding space debris is not just theoretical. The findings are underscored by past incidents, such as the 2022 episode involving a hefty 20-tonne section of a rocket that led to the temporary closure of airspace over Spain and France. Events like this underscore how space junk can create unanticipated challenges for commercial aviation, prompting authorities to take preemptive action to protect civilian flights.

As the frequency of rocket launches continues to rise, researchers advocate for prompt action from policymakers. First author Ewan Wright, an interdisciplinary studies doctoral student at UBC, highlights a recent SpaceX Starship explosion shortly after launch that necessitated a rapid airspace closure. In that instance, authorities were equipped with precise data regarding the trajectory of the debris, allowing them to establish exclusion zones for air traffic. However, uncontrolled debris re-entries present a much higher degree of uncertainty, compelling air traffic controllers to make difficult decisions without sufficient information.

When rockets deliver satellites into orbit, substantial portions—often including entire stages of the launch vehicle—are frequently abandoned in space. Should these remnants descend from orbit at a low enough altitude, they can re-enter the Earth’s atmosphere in a manner that is far from controlled. Although the majority of these materials incinerate upon re-entry, a significant number of fragments may still survive the descent and land anywhere on Earth, including heavily trafficked airspaces.

To contextualize the risks, the UBC researchers conducted a thorough analysis based on air traffic patterns observed on the busiest flying day in 2023. They correlated this data with the historical probability of rocket debris re-entering various air traffic zones, spanning a decade’s worth of information. Their analysis revealed that the highest air traffic density occurred over Denver, Colorado, where an aircraft operates on average every 18 square kilometers. Using this data point, the researchers extrapolated the probabilities of rocket junk re-entering active airspace. Particularly concerning were zones with 10 percent or greater air traffic density, such as the highly trafficked corridor between Vancouver and Seattle, which revealed the alarming 26 percent chance of re-entries occurring annually.

Notably, the regions over southern Europe that mandated airspace closure in 2022 were determined to represent only five percent of the peak traffic density. Alarmingly, the researchers’ findings indicate a 75 percent annual chance of rocket debris re-entering such low-density areas across the globe. The statistical likelihood of rocket debris colliding with an aircraft is also notable, estimated at approximately one in 430,000 annually, highlighting the necessity for preventative measures despite seemingly favorable odds.

When faced with the threat of encroaching space debris, aviation authorities are often placed in precarious positions of decision-making. They can either permit flights to continue, subject to risk, or opt to divert routes or even close airspace entirely. Wright and his colleagues challenge this current state of affairs and propose that the space industry must take greater responsibility for its impact on air travel. This is not merely an operational concern; it is a question of risk management and shared responsibility across industries.

Presently, the space industry tends to operate with little regard for the potential downstream ramifications its operations have on commercial aviation. According to co-author Dr. Aaron Boley, an associate professor in UBC’s physics and astronomy department, these uncontrolled re-entry scenarios are more a matter of design choice than an inherent requirement of space launches. Thus, the contention arises that the space sector is inadvertently passing its associated risks onto airlines and their passengers.

The study also highlights that substantial solutions exist. Instead of leaving rocket stages adrift in space to eventually fall back to Earth uncontrolled, there are feasible alternatives. By designing rockets capable of controlled re-entry, which would ideally self-destruct over unpopulated areas like the ocean, the threats posed to civilian air travel could be significantly mitigated. However, achieving such reforms necessitates an international commitment to standardization in rocket designs and operational protocols.

As the space sector continues to witness unprecedented regulatory and operational challenges, industry stakeholders and government entities must unite in order to establish a collective framework. Dr. Michael Byers, a UBC political science professor and co-author on the study, asserts that absent a collaborative approach, individuals and organizations producing rockets are unlikely to invest the requisite resources into improving safety and design unless compelled by collective international standards. Therefore, the responsibility lies with nations to engage in dialogue and action to elevate safety measures for both airborne passengers and those impacted by space operations.

In conclusion, the UBC study not only underscores the tangible risks associated with space debris on busy flight paths but also emphasizes the need for intervention by policymakers to redefine safety protocols in both the aviation and aerospace industries. The time for collaborative effort is now; the increasing trajectory of rocket launches and air traffic necessitates an urgent reevaluation of how these systems coexist. Without decisive action, the harmonious operation of aviation and space exploration may be placed in jeopardy, raising questions about safety, risk management, and the responsibilities inherent in progressing toward an even more interconnected future.

Subject of Research: Risks of space debris re-entry on commercial aviation
Article Title: The Perils of Space Junk: Risk Factors for Civilian Air Travel
News Publication Date: October 2024
Web References: Nature Study Link, IATA Press Release
References: UBC study in Scientific Reports; DOI – 10.1038/s41598-024-84001-2
Image Credits: University of British Columbia

Keywords

Space debris, aviation safety, uncontrolled re-entry, rocket launches, air traffic management, collision risk, aerospace industry, environmental standards, international cooperation, risk management.