SPACE SUSTAINABILITY AS A GLOBAL CHALLENGE; THE
KESSLER APOCALYPSE – QUESTIONING THE ADEQUACY OF
INTERNATIONAL SPACE LAW TO REGULATE SPACE DEBRIS
I. WOOD
Corresponding Author: Space Sustainability as a Global Challenge; The Kessler Apocalyse – Questioning the Adequacy of International Space Law to Regulate Space Debris
Although some may argue that space debris has not consistently posed significant challenges during humanity’s time in outer space, the increasing frequency of both intentional and unintentional debris-generating events demonstrates that the risks to space sustainability are not only present but escalating. These incidents, ranging from satellite collision to anti-satellite (ASAT) tests, bring unprecedented dangers to the space environment. Therefore, preventing space debris accumulation from reaching a critical point in our orbital ecosystem is a pressing priority. This is especially true given the vast and growing number of space objects currently orbiting the Earth, each presenting new threats and complexities to the overall stability of the orbital environment.
With this understanding in mind, maintaining space sustainability largely hinges on preventing the onset of what is known as Kessler syndrome, a concept introduced by NASA scientist Donald Kessler. Kessler’s theory made us fundamentally reassess the sustainability of Earth’s orbit space. Essentially , his hypothetical predicts a scenario in which collisions in space trigger a chain reaction of further collisions, exponentially increasing debris and rending the orbital environment increasingly hazardous and ultimately unusable. The worst possible scenario, sometimes referred to as a ‘Kessler Apocalypse’, would have profound and devastating impacts on global society, incapacitating space-based infrastructure such as satellites and forcing human civilisation to revert to analogue methods of communication and navigation.
The principal reasons why we contend that current international space law remains inadequate stem from the fact that much of it was established before Donald J Kessler’s 1978 insights into space sustainability. Existing treaties, like the Outer Space Treaty of 1967 and the Liability Convention of 1972, focus more on jurisdictional and liability concerns than on long-term sustainability. With the exception of the Moon Treaty of 1979-which, while addressing sustainability, concentrates primarily on activities conducted on the Moon and other celestial bodies – there has been little substantive development in international law regarding the sustainability of Earth’s orbital space. This legal lag hinders our ability to manage risks effectively.
Recommendations
The three main recommendations to prevent a potential Kessler Apocalypse from occurring are as follows:
1) Creation of a new piece of soft international space law, tailored to space sustainability
2) Development of new, clearly differentiated definitions for “space debris” and “space object” inspired by maritime law principles
3) Implementation of an innovative cap-and-trade system for space debris regulation
Subsequently, these recommendations will be critically examined to explore how they could be effectively implemented. Further analysis will focus on how these initiatives could foster a coordinated international response aimed at promoting long-term sustainability in outer space activities.
Creation of a new piece of soft international space law
Binding international space law is unappealing in the current outer-space climate, as demonstrated by the recent agreements. For example, the Moon Treaty has failed to receive widespread acceptance. The trend of fewer signatories to binding international space law indicates that the international community desires autonomy in their outer space operations. Now, we believe that a binding international treaty for space debris could be possible, only if a massive space debris-related incident were to occur, which would create a global reactive response to bring signatories together for space sustainability; similar to how the Cold War influenced the Outer Space Treaty to prevent potential space wars.
Soft international law may be our only hope, especially as it gives autonomy to signatories . As seen with the recent adoption of the Zero Debris Charter, which aims to set a goal for every signatory to have no net addition of space debris in orbit by 2023, non-binding agreements are gaining traction and are seeming to be the way forward for debris governance. Fundamentally, the new soft international law must be more technical and comprehensive, as the IADC and UNCOPUOS have fallen short in terms of space sustainability. Merely repeating existing debris practices, which are already commonplace in the space industry. For example, both debris guidelines recommend outdated requirements, such as having a 25-year post-mission orbital lifetime limit in Low Earth Orbit, which is an expected requirement in the space industry. Moreover, these guidelines have already failed to foresee future developments such as mega satellite constellation, which have shorter lifespans.
New ‘Space debris’ definition inspired from maritime law
A new space debris definition inspired by maritime law is essential to ensure long-termspace sustainability. This becomes especially critical when examining the confusion of Inter-Agencu Space Debris Coordination Committee (IADC) debris guidelines. The IADC defines space debris as ‘all man-made objects, including fragments and elements thereof, in Earth’s orbit or re-entering the atmosphere that are non-functional ‘. This definition is often viewed as problematic due to its striking similarity to the Liability Convention’s definition of space object , which states that a space objects ‘includes component part of a space object as well its launch vehicle and parts thereof’. These definitions overlap by focusing heavily on component parts and man-made objects, leading to an ambiguous distinction between space object and space debris.
Scholars have often likened outer space to international waters, providing a strong rationale to draw inspiration from maritime law to resolve this ambiguity. In particular, space debris can be conceptually compared to maritime shipwrecks. A significant observation is that, similar to space debris, shipwrecks have never been defined at the international level, including in the UN Convention on the Law of the Sea or the International Convention on Salvage.
One notable aspect of international maritime law is that it distinctly defines ships and vessels separately from shipwrecks. This distinction is largely based on functionality. For example, a vessel is defined as ‘any structure capable of navigation’, whereas, shipwrecks, as seen in the French Maritime Code, are defined by a three-criteria system: (i) the vessel cannot stay afloat (ii) it has no crew on board, and (iii) no measures have been taken to keep it safe.
Drawing inspiration from the French Maritime Code, we propose a new criteria-based definition for space debris that can clearly differentiate it from space objects. Under this definition, space debris must (a) be non-functional (b) unresponsive (c) uncontrollable, and (d) unidentifiable. This proposed framework ensures that each space object is evaluated based on these criteria and must meet at least three of the four criteria to be classified as debris. For example, Cosmos 2251 satisfies three out of the four criteria: the Russian government reported the satellite had ceasing function in 1995, making it non-functional and uncontrollable and unresponsive, but it remains identifiable, as it continues to be under Russia jurisdiction and ownership.
Inventive Cap and Trade space debris system
The potential Kessler cap-and-trade system could foster a comprehensive global response to space sustainability challenges. However, a key concern with such a system is that if we were to focus on allocating existing debris responsibilities to spacefaring states, this system would likely place an overwhelming financial burden on nations such as the United States and Russia. These two countries, being the largest contributors to space debris, could find themselves disproportionately accountable under the system, thereby risking their disengagement from the framework
Isolating such critical players from a Kessler cap-and-trade system would significantly undermine its overall efficacy. Nonetheless, the existence of the Paris Agreement illustrates that there is global willingness to embrace international cap-and-trade systems. As seen in the Agreement, various nations have incorporated carbon pricing mechanisms into their national environmental strategies, showcasing the feasibility of such an approach for space sustainability
The paper proposes the implementation of a Kessler credit system, which would operate as a space-specific cap and trade model. This system would ensure that each spacefaring state, as a signatory, commits to an annual target for space debris removal or prevention, customised to reflect its stage of space development. The establishment of debris caps would be determined on a case-by-case basis, reflecting each state’s unique circumstances. Moreover, spacefaring nations would be able to trade credits among themselves, depending on whether they exceed or meet their predetermined space debris removal target, thereby incentivising collective global action.
Conclusion
In summary, the current framework of international space law has considerable room for expansion, with valuable lessons to be drawn from environmental and maritime law. These lessons can be developed into more technical and robust legal frameworks to enhance the state of international space law and promote sustainable practices in space. Initiatives such as the Zero Debris Charter represent meaningful steps forward in the pursuit of more sustainable space policies, but there remain significant gaps that must be addressed. Undoubtedly, there are still giant leaps to be made, requiring the international community to take decisive actions in the near future.