Disclaimer: The views expressed in this work represent the personal views and conclusions of the authors writing in their personal capacity and do not reflect the official position of the Stanford Space Law Society.

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Public, commercial, and governmental interest in space has been skyrocketing over the past few decades, with current estimates of the space economy reaching a value worth $1.8 trillion by 2035 with the advancement of emerging new space technologies.[1] From the rise of commercial launch operators such as SpaceX, Blue Origin, and Rocket Lab, launch costs have decreased dramatically, allowing for a tremendous growth in the number of spacecrafts crowding the Lower Earth Orbit (LEO) regions.[2] In the past decade, the number of objects being launched into space has reached record highs, with the United Nations Office for Outer Space Affairs recording 2,849 objects sent into space in 2024.[3] SpaceX alone plans to increase their Starlink constellation and replace 42,000 satellites every 5 years.[4] This is roughly equivalent to a fourfold increase in the active satellite population as of 2024.[5]

However, the rise in the number of spacecrafts entering Earth’s orbits is not without consequences. In 2023, growing congestion in LEO led to over 600,000 daily Conjunction Data Messages (CDMs), indicating close encounters between satellites.[6] This is a 200% increase from three years prior.[7] With recent increases in LEO space traffic, the International Space Station performed two collision avoidance maneuvers in 2022 against several commercial Earth-imaging satellites.[8]

Space Trash Complicates Current Space Traffic Management Systems and Collision Avoidance Protocols

Any collision results in the creation of hundreds to thousands of pieces of new debris, which, in a cascading effect, further increases the risk of collisions and debris generation.[9] This is referred to as Kessler’s syndrome, and some scientists are already worried this phenomenon is already in progress.[10] One of the first satellite collisions recorded, which was between the Iridium 33 and Cosmos 2251 satellites in 2009, resulted in the addition of over two thousand pieces of new debris across multiple orbit regimes.[11] With no easy solutions for removing space debris in Earth’s orbits, NASA’s Orbital Debris Program Office estimates that debris resulting from collisions like Iridium 33 and Cosmos 2251 can stay in orbit for thousands of years in high orbits, posing long-term risks to critical infrastructure like GPS and broadcasting satellites.[12][13]

Today, there are estimates of over 128 million particles between one millimeter and one centimeter and 900,000 items between one and ten centimeters orbiting Earth.[14] For the 45,000-plus items larger than 10 cubic centimeters in Earth’s orbit, catalogs such as the U.S. Space Surveillance Network (SSN) provide both surveillance and foundational space situational awareness for the U.S. Department of Defense and other space entities.[15] However, this still leaves several questions unanswered: Who is responsible for the space debris that lands on Earth? What are the legal implications when these tracked and untracked objects collide with one another?

Established International Resolutions and Legal Frameworks Dedicated to Mitigating Space Object Concerns

The principles and laws governing damages incurred by space objects are derived from resolutions adopted by the United Nations in the 1960s and 70s: the “Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies” (the Outer Space Treaty) and the “Convention on International Liability for Damage Caused by Space Objects” (the Liability Convention).

Article VII of the Outer Space Treaty establishes that countries shall be held internationally liable for damage caused by the space objects they launched.[16] The Liability Convention, adopted five years later, further elaborates on this principle by holding launching countries absolutely liable for damage caused by their “space objects” on Earth’s surface or to aircraft, even if this damage was caused by a private company from that country.[17]

Space Debris Should Be Considered A “Space Object”

Article I(d) of the Liability Convention defines “space object” to include “component parts of a space object as well as its launch vehicle and parts thereof.”[18] The Space Debris Mitigation Guidelines published by the United Nations in 2007 defines space debris as “all man-made objects, including fragments and elements thereof, in Earth orbit or re-entering the atmosphere, that are non-functional.”[19] The guidelines also refer to component parts of a space object as space debris interchangeably. Therefore, the Liability Convention should equally apply to injuries involving space debris.

Minimal Legal Consequences for Noncompliance

By transferring these guidelines into national or international regulations, compliance in a joint effort to mitigate space debris could be improved. However, until then, there continue to be minimal to no legal consequences for noncompliance.

At the time of writing, in order to obtain compensation from an event where a space object damaged someone’s property back on Earth, the government of the damaged party’s country would need to make a claim for compensation to the launching country through diplomatic channels. There has only been one successful invocation of the Liability Convention, when the Soviet Union’s Cosmos 954 satellite fell into Canada in 1978.[20] This settlement set certain precedents for mitigating crises involving space objects falling back to Earth, but currently, there are no guidelines for resolving issues that arise from space debris damaging someone else’s space object in space. Furthermore, it would be difficult for anyone to prove who is responsible for the damage resulting from the debris. Even if the responsible party of the space debris is identified, the injured party needs to prove that this company or institution was negligent.[21] What qualifies as negligence, however, is not defined because the Liability Convention does not list how a space object could cause damages. Not only is the standard of apportioning liability unclear for the initial collision, but the assignment of liability for subsequent collisions by a spacecraft’s debris is functionally difficult. Article IV 1(b) of the Liability Convention states that the liability for a space debris collision to a third party is assigned to the party responsible for the initial collision.[22] If the initial collision’s liability remains uncertain, tracing the full chain of cascading debris impacts becomes nearly impossible.

Currently, there have been no cases of any party being held liable for space debris collisions in space. However, this lack of precedent and clarity in applying liability for debris collisions is concerning, considering how space debris will continue to increase in our orbits and collisions will become more common. Even if an entity is found liable for a collision resulting from debris of their space object, it is difficult to envision a remedy that goes beyond monetary damages. The ability of legal remedies to prevent future collisions or adequately respond to a potential Kessler’s syndrome is also questionable.

Inspiration from Maritime Law

Cognizant of the irreversible damage of oversaturating our orbits with space debris, the space industry could draw inspiration from maritime regulations put in place to prevent pollution in Earth’s oceans.

Article IX of the Outer Space Treaty states that countries must “avoid harmful contamination” of outer space and conduct activities in outer space with due regard to the corresponding interests of other countries.[23] Similar to the Outer Space Treaty, the International Convention for the Prevention of Pollution from Ships (MARPOL), includes measures for preventing marine pollution before the harm becomes irreparable.[24]

In 2021, Diana Wilhelmsen Management Limited, a Cyprus-based shipping company, was fined $2 million for violating the Act to Prevent Pollution from Ships and neglecting its professional and legal obligations to the environment.[25] Both MARPOL and the Outer Space Treaty share similar principles of preventing further pollution by facilitating responsible operations in their respective domains. Relevant case precedents in maritime law can further shed light on how private parties could be held liable for not abiding by these principles in space.

Space Debris Reduction in the United States

In the United States, the main preventative measures to reduce space debris are launch and reentry licenses. In 2020, the Federal Aviation Administration (FAA) released Part 450, “Launch and Reentry License Requirements” as a way to streamline the licensing process for commercial space launches as well as reentries.[26] The license can support multiple launches and re-entries at multiple locations, and Part 450 outlines the critical safety assessments that need to be made for commercial space operations before proper licenses can be distributed.

However, Part 450 is subject to possible changes in regulations in the near future.[27] The FAA announced the development of a new industry collaboration aerospace committee known as the Launch and Reentry License Requirements Improvement Aerospace Rulemaking Committee (SpARC) to examine potential changes to FAA’s current Part 450 licensing procedures.[28] Internationally, regulations differ based on the existing national space agency or regulatory body in the specific country. Operators may need to obtain licenses from each relevant country depending on their operational scope.[29] This creates difficulties with unstandardized international regulations for space launch and reentry protocols.

In a proactive effort to address orbital debris, the FAA introduced several new preventative measures in 2023 aimed at reducing the long-term impact of upper stage launch vehicles on the space environment.[30] These measures include

1. Orbital Debris Assessment Plan: For any launches with an altitude greater than 150 kilometers, an operator must provide analyses on: what debris is generated, the associated risks for populations, and appropriate processes for debris removal prior to the operation of the spacecraft.[31]
2. Five Millimeter Threshold Size for Orbital Debris: A threshold for orbital debris size is set to five millimeters in any dimension, recommended to encompass descriptions of “all human-generated debris in Earth orbit.”[32]

• Post Launch Debris Disposal: Launch vehicle stages and components have specific timeframes for disposal, with specific categories such as controlled atmospheric disposal (30 days after mission completion), direct retrieval (5 years after mission completion), and uncontrolled atmospheric disposal (25 years after launch).[33]

Conclusion

Without clear insight into how space debris will be removed from our orbits, it is crucial that launching countries share the same conviction in minimizing the amount of debris in their launches and re­‑entries. These efforts, however, must be made jointly between countries, both in the preventive and reparative stages, for managing space debris in and out of orbit. In addition to the existing SSN, implementing a worldwide system of tracking space debris internationally could aid in preventing collisions from space debris and identify parties to hold liable for legal remedies back on Earth.[34] By developing further advanced monitoring and tracking systems, standardized tools for assessing ground casualty risks from possible reentrance of objects back to Earth could be developed to mitigate damage from space debris on Earth.[35]

For reparative measures, further development on the existing Liability Convention is needed to establish proper frameworks for handling responsibility for damage incurred from space debris on Earth and in orbit. The limitations with fault-based liability of proving negligence must be addressed, with the increasing complexity of space operations. Liability should also be expanded to express obligations from commercial entities, especially with the increasing involvement of private companies in space activities. The space industry could look to the enforcement of international maritime law for guidance in demanding accountability by private entities.

It seems the question of who takes out the trash in space is still orbiting around us. However, one thing is clear: this trash will not go away unless we all do it together.

* Grace Kim is pursuing a Doctorate degree in Aeronautics and Astronautics (expected graduation in 2028) at Stanford University; Laurel Kim is pursuing a joint degree of Doctor of Jurisprudence (JD) and Master’s in Public Policy (expected graduation in 2026) at Stanford University.

[1] World Economic Forum, “Space Is Booming. Here’s How to Embrace the $1.8 Trillion Opportunity,” World Economic Forum, April 8, 2024, https://www.weforum.org/stories/2024/04/space-economy-technology-invest-rocket-opportunity/.

[2] Denise Chow, “To Cheaply Go: How Falling Launch Costs Fueled a Thriving Economy in Orbit,” NBC News, April 8, 2022, https://www.nbcnews.com/science/space/space-launch-costs-growing-business-industry-rcna23488.

[3] Edouard Mathieu, Pablo Rosado, and Max Roser, “Annual Number of Objects Launched into Space,” Our World in Data, 2025, https://archive.ourworldindata.org/20250624-125417/grapher/yearly-number-of-objects-launched-into-outer-space.html.

[4] Federal Communications Commission, Space Exploration Holdings, LLC Request for Orbital Deployment and Operating Authority for the SpaceX Gen2 NGSO Satellite System, 37 Federal Communications Commission Record 14882 (16) 14940, note 437 (November 29, 2022).

[5] ABI Research, “Over 480 Orbital Launches and 43,000 Active Satellites Expected by 2032,” ABI Research, December 19, 2024, https://www.abiresearch.com/press/over-480-orbital-launches-and-43000-active-satellites-expected-by-2032.

[6] Christian Ramos et al, Lessons Learned on Mega-Constellation Deployments and Impact to Space Domain Awareness (National Aeronautics and Space Administration, 2023), https://ntrs.nasa.gov/api/citations/20230012741/downloads/AMOS_2023_Paper_Final.pdf.

[7] Id.

[8] Brett Tingley, “International Space Station Fires Thrusters to Dodge Space Junk,” Space.Com, March 14, 2023, https://www.space.com/international-space-station-dodge-space-junk-march-2023.

[9] Hugh G. Lewis, “Understanding Long-term Orbital Debris Population Dynamics,” Journal of Space Safety Engineering 7, no. 3 (September 2020): 164–70, https://doi.org/10.1016/j.jsse.2020.06.006.

[10] Jackie Wattles, “What Is ‘Kessler Syndrome’ — and Why Do Some Scientists Think the Space Disaster Scenario Has Already Started?,” CNN, December 27, 2024, https://edition.cnn.com/2024/12/27/science/space-junk-earth-kessler-syndrome.

[11] Brian Weeden, 2009 Iridium-Cosmos Collision Fact Sheet (Secure World Foundation, November 10, 2010), https://www.swfound.org/publications-and-reports/2009-iridium-cosmos-collision-fact-sheet.

[12] “Space Debris 101,” Aerospace Corporation, accessed August 20, 2025, https://aerospace.org/article/space-debris-101#:~:text=There%20is%20no%20easy%20or,heavy%20and%20difficult%20to%20move.

[13] “Frequently Asked Questions,” Astromaterials Research and Exploration Science, accessed August 20, 2025, https://orbitaldebris.jsc.nasa.gov/faq/#:~:text=Above%201%2C000%20km%2C%20orbital%20debris,a%20thousand%20years%20or%20more.

[14] Lewis, supra note 9.

[15] National Aeronautics and Space Administration, “Chapter 12 Identification and Tracking Systems,” in State-of-the-Art of Small Spacecraft Technology (National Aeronautics and Space Administration, February 5, 2025), https://www.nasa.gov/smallsat-institute/sst-soa/identification-and-tracking-systems/.

[16] Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, Including the Moon and Other Celestial Bodies article VII, opened for signature January 27, 1967, 610 United Nations Treaty Series 8843 (entered into force October 10, 1967), https://treaties.un.org/doc/Publication/UNTS/Volume%20610/volume-610-I-8843-English.pdf.

[17] Convention on the International Liability for Damage Caused by Space Objects article I(d), opened for signature March 29, 1972), 961 United Nations Treaty Series 13810 (entered into force September 1, 1972), https://treaties.un.org/doc/Publication/UNTS/Volume%20961/volume-961-I-13810-English.pdf.

[18] Id.

[19] Space Debris Mitigation Guidelines of the Committee on the Peaceful Uses of Outer Space (United Nations Office for Outer Space Affairs, 2010), 1, https://www.unoosa.org/pdf/publications/st_space_49E.pdf.

[20] Bryan Schwartz and Mark L. Berlin, “After the Fall: An Analysis of Canadian Legal Claims for Damage Caused by Cosmos 954,” McGill Law Journal 27, no. 4 (September 1982): 677.

[21] “Space Law: Liability for Space Debris,” Panish Shea Ravipudi LLP, accessed August 20, 2025, https://www.aviationdisasterlaw.com/liability-for-space-debris/#:~:text=Who%20might%20be%20liable%20for%20damages%20that%20space,in%20which%20a%20space%20object%20might%20cause%20damages.

[22] Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, Including the Moon and Other Celestial Bodies article IV 1(b), supra note 17.

[23] Convention on the International Liability for Damage Caused by Space Objects article IX, supra note 16.

[24] Protocol of 1978 Relating to the International Convention for the Prevention of Pollution from Ships, 1973 (with Annexes, Final Act and International Convention of 1973), concluded on February 17, 1978, 1340 United Nations Treaty Series 22484 (entered into force October 2, 1983), https://treaties.un.org/doc/Publication/UNTS/Volume%201340/volume-1340-A-22484-English.pdf.

[25] United States Department of Justice Office of Public Affairs, “Shipping Company Fined $2 Million in a Multi-District Case for Concealing Illegal Discharges of Oily Water into the Atlantic Ocean,” Press release, September 23, 2021, https://www.justice.gov/archives/opa/pr/shipping-company-fined-2-million-multi-district-case-concealing-illegal-discharges-oily-water.

[26] 14 Code of Federal Regulations § 450 (2025).

[27] Jeff Foust, “FAA Optimistic Launch Companies Will Switch to New Regulations by 2026 Deadline,” SpaceNews, January 29, 2025, https://spacenews.com/faa-optimistic-launch-companies-will-switch-to-new-regulations-by-2026-deadline/#:~:text=The%20transition%20to%20Part%20450,for%20licensing%20launches%20and%20reentries.

[28] Federal Aviation Administration, Launch and Reentry License Requirements Improvement Aerospace Rulemaking Committee, November 14, 2024, https://www.faa.gov/regulationspolicies/rulemaking/committees/documents/launch-and-reentry-license-requirements.

[29] “Space Licensing in the United States,” ANGELS, accessed August 20, 2025, https://spacelaws.com/articles/space-licensing-in-the-united-states/.

[30] Mitigation Methods for Launch Vehicle Upper Stages on the Creation of Orbital Debris, 88 Federal Register 65835 (proposed September 26, 2023).

[31] Id. at 65836.

[32] Id. at 65844.

[33] Id. at 65847.

[34] “Space Debris 101,” supra note 12.

[35] “Mitigating Space Debris Generation,” European Space Agency, accessed August 20, 2025, https://www.esa.int/Space_Safety/Space_Debris/Mitigating_space_debris_generation.