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Markkula Center for Applied Ethics

On the Pressing Issue of Space Debris

Generated image of debris in space. Photo credit: WikiImages/Pixabay

Generated image of debris in space. Photo credit: WikiImages/Pixabay

Alec Hattan '23

Alec Hattan '23 graduated from Santa Clara University with a major in English, a minor in music, and was a 2022-23 environmental ethics fellow with the Markkula Center for Applied Ethics. Views are his own.


On February 10, 2009, at approximately 4:56 UTC, two communications satellites, Kosmos 2251 and Iridium 33, collided high over the Siberian wilderness. Kosmos was a Russian defunct military communications satellite and Iridium a commercial satellite controlled by an American communications company in McLean, Virginia. Ten days after the collision, NASA estimated that 1,000 new pieces of space debris had been strewn across Low Earth orbit [1]. NASA defines orbital space debris as “any human-made object in orbit about the Earth that no longer serves a useful function. Such debris includes nonfunctional spacecraft, abandoned launch vehicle stages, mission-related debris, and fragmentation debris” [2]. As of today, NASA estimates that there are approximately 23,000 pieces of debris larger than ten centimeters, half a million pieces of debris larger than one centimeter, and approximately one hundred million pieces of debris larger than a millimeter. These objects travel at speeds of up to 17,500 miles per hour, which is fast enough for even tiny paint flecks to damage a spacecraft [1]. The proliferation of space debris poses an imminent threat to humanity’s space exploration endeavors and necessitates immediate action to mitigate its disastrous consequences.

Kessler Syndrome, named after the NASA scientist Donald J. Kessler, refers to the potential scenario where the density of space debris reaches a critical point and triggers a cascade of collisions in low Earth orbit, encircling the planet in a debris field. Proposed by Kessler with Burton G. Cour-Palais in 1978, they argue that when the Earth’s orbit becomes crowded enough, one chance collision could set off a chain reaction of collisions that will generate a thick cloud of hypervelocity particles around Earth [3]. Events like the 2009 satellite collision are not rare. In fact, just as Kessler and Cour-Palais theorized, these incidents are becoming more commonplace. Prior to Kessler and Cour-Palais proposing their theory in 1978, there had been only 73 events that generated significant debris since the first recorded debris-creating event in 1961 – a 23-year window. Since then – a 45-year window – there have been 319 incidents in Earth orbit causing significant amounts of space debris [4]. This is a catastrophe. As Kessler and Cour-Palais note in their conclusion, “the process which will produce these fragments are totally analogous to the processes that probably occurred in the formation of the asteroid belt but require a much shorter time” [3]. The creation of a debris belt would threaten humankind’s ability to access space or conduct any activities in space including having communications satellites, navigational satellites, and scientific satellites or probes, not to mention prevent further crewed missions into space.

Statistically speaking, the universe seems like it should be bubbling with extraterrestrial life. In just the past decade, astronomers have found thousands of exoplanets and roughly 200 planets comparable in size to Earth, and that’s just what we have seen in a small part of the sky [5]. How many life-supporting planets are there in the universe? It seems that in 13.8 billion years, some intelligent species out there certainly should have achieved a long-lasting interstellar civilization. However, with no current evidence of intelligent life in the observable universe, it perhaps might make us wonder if such civilizations are even possible. In 1996, American economist and author Robin Hanson published an online essay proposing the “Great Filter” hypothesis, which suggests that the lack of evidence for extraterrestrial life implies a failure for civilizations to evolve to a point of interstellar colonization [6]. No such civilization appears to exist in the Milky Way or else it should be visible. The implied question in Hanson’s theory is whether the Great Filter is behind us or ahead of us. Have we made it further than everyone else, or is extinction lying in wait just around the corner? The possibility for the creation of a debris belt suggests that perhaps an obstacle lies ahead of us, just as it has, perhaps, laid before innumerable previous civilizations at this stage in their histories. Perhaps we have yet to pass the Great Filter. If we allow space debris to completely encompass Earth and put an end to space exploration, we may well be trapped on Earth and possibly face extinction as we unsustainably destroy the planet’s resources and quarrel over our all-too-human borders. Mitigating this disastrous risk and ensuring long-lasting life is profoundly important.

With our species’ future in mind (and all Earthly life – which might, after all, die with us), we should seek the common good for humanity and the environment [7]. The common good refers to actions that benefit the well-being of all society and the planet. Cooperating on such a scale will be a challenge unlike any other humanity has ever before faced, but it is also an opportunity to protect our access to a bright future. And hope is not lost, we’ve come together in times of dire need before. Following World War II, the UN was founded by fifty nations to “practice tolerance and live together in peace with one another as good neighbors, and to unite our strength to maintain international peace and security… and to employ international machinery for the promotion of the economic and social advancement of all peoples” [8].  Unfortunately, political tensions have been encouraging nations to develop and test anti-satellite weaponry, which is actively creating more space debris. In 2007, China caused an international uproar when it “destroyed one if its own satellites, an action that left hundreds of pieces of debris in space” [9]. Even more egregious was Russia’s anti-satellite test in November of 2021 which forced crew members of the International Space Station to “scramble into their spacecraft for safety” [10]. Western countries seem aligned on their goals for space debris mitigation, with the Pentagon even seeding money to companies developing space debris removal spacecraft [11]. Now, the light turns towards countries like China and Russia to join the fight against space debris. Perhaps, as members of the UN, they will be inclined to participate if this becomes a serious focal point of continued international discussion.

The Markkula Center for Applied Ethics at Santa Clara University cites ethicist John Rawls, who defines the common good as “certain general conditions that are…equally to everyone’s advantage” [12]. They give examples of the common good like affordable public health care, effective systems for public safety, peace among nations, a just government, an unpolluted natural environment, and a flourishing economy. These things demonstrate actions that lift everyone in society up. Preventing and cleaning up space debris is also one of these things. Uniting through the common good to prevent becoming trapped on Earth, thus risking extinction is tremendously important. From an ethical perspective, there is a moral imperative to guarantee that human civilization endures and grows in prosperity. It’s not too late to choose the common good.


Works Cited

[1] Oleksyn, Veronika. "What a mess! Experts ponder space junk problem." USA Today, February 19, 2009. 

[2] Garcia, Mark. “Space Debris and Human Spacecraft.” NASA website, 14 Apr. 2015.

[3] Kessler, Donald J., and Burton G. Cour-Palais. "Collision Frequency of Artificial Satellites: The Creation of a Debris Belt." Journal of Geophysical Research, vol. 83, no. A6, 1978, pp. 2637-2646. doi: 10.1029/JA083iA06p02637

[4] McDowell, Jonathan. "Space Debris Clouds." Planet 4589, 18 May 2023.

[5] NASA, “Exoplanet Exploration: Planets beyond Our Solar System,” NASA website, August 11, 2023.

[6] Hanson, Robin. "The Great Filter – Are We Almost Past It?" 15 Sep. 1998.

[7] The ITEC “Anchoring Principle.” In José Roger Flahaux, Brian Patrick Green, and Ann Gregg Skeet, Ethics in the Age of Disruptive Technologies: An Operational Roadmap (The ITEC Handbook), Markkula Center website, 2023. 

[8] United Nations. “The UN Charter.” United Nations website.

[9] Zissis, Carin. "China’s Anti-Satellite Test.” CFR, 22 Feb. 2007.

[10] Atwood, Kylie, et al. "US says it ‘won’t tolerate’ Russia’s ‘reckless and dangerous’ anti-satellite missile test." CNN website, 16 Nov. 2021. 

[11] Davenport, Christian. "The Pentagon is looking for garbage collectors in space." The Washington Post, 27 Jan. 2022. 

[12] Vasquez, Manuel, et al. “The Common Good.” Markkula Center website. 14 August, 2014.


Aug 17, 2023