Toward the Sustainability of Outer Space: Addressing the Issue of Space Debris

Abstract

The legacy of >50 years of human space faring has brought impressive technical and scientific achievements; however, it has also led to the growing population of space debris. These objects serve no useful purpose in space, but instead place man, the Earth, and useful space objects at risk. This article examines the policy gaps associated with addressing the problem of space debris, including the absence of international legal framework, responsibility and liability for debris creation, and identification of debris as separate from space objects. It goes on to proffer solutions addressing this policy gap, which include the adaptation of environmental law principles, a definition of space debris under international law, and a workable remediation regime.

Introduction

“The importance of securing humanity's doorstep to outer space cannot be overstated and should indeed be a priority for all nations.”¹

The existence of space debris is a direct implication of human activities in outer space. These pieces of debris are uncontrollable man-made objects in space, useless and causing more harm than good.*^,2 They include items such as tools lost by astronauts during extravehicular missions, spent rocket stages, inoperative satellites, and pieces generated from satellite fragmentation events. Fragmentation events can be accidental—as in the case of nondeliberate in-orbit collisions—or intentional—as in the case of antisatellite weapons tests. Debris orbit Earth at dangerously high speeds,^†^,3 and their exponential growth threatens both the sustainability of outer space and safety on Earth. Responding to this problem opens up several legal and technical issues, ranging from responsibility and liability for debris creation to implementation and legality of remediation regimes. International law currently prohibits the harmful contamination of outer space.^‡ However, this fundamental principle of space law lacks specificity in the context of space debris. Besides, the current space treaties^§ do not define, address, or even mention space debris. Nevertheless, the extension of man's active environment from Earth to space indicates the prospects of adapting environmental law principles to fill certain voids in the current space law regime. This article, therefore, examines the policy gaps in addressing the issue of space debris, as well as recommendations on how the international community can go about fixing these gaps. The article examines orbital debris, the current legal framework, and policies concerning orbital debris and solutions to the highlighted problems of the current legal framework and policies.

Orbital Debris: Numbers and Historic Events

Since the rocket body from the launch of Sputnik 1 in 1957 became the first piece of space debris, the quantity of space debris has grown at a significant rate.⁴ On January 11, 2007, China deliberately destroyed one of its old weather satellites (Fengyun 1-C), and this test alone increased the number of trackable space objects by 25%.⁵ It also marked the largest new creation of debris in history up to that point.⁶ On March 27, 2019, India also conducted a similar test through its “mission Shakti.”⁷ This made India the fourth nation, after the United States, Russia, and China, to have conducted such a test.⁸

Collision is also a major source of space debris. One of the most remarkable of such events is the February 10, 2009, collision of one of Russia's old military satellites. The satellite collided with a then operating Iridium communications satellite. The collision created >200,000 pieces of debris and marked the first collision of 2 intact satellites in space.⁹

Currently, the European Space Agency (ESA) estimates space debris to include 34,000 objects >10 cm to 900,000 objects between 1 and 10 cm, and 128 million objects between 1 mm and 1 cm.¹⁰ Scientists have warned that these numbers and statistics will only increase, even if we do not put anything in orbit.^**

Orbital Debris: Access to Space Resources and Safety

Debris pose risks to both Earth and space. With respect to access to space and space resources, debris endangers both current and prospective space missions. NASA notes that most space debris can reach speeds ∼8,046.72 meter per second (almost 7 times faster than a bullet), fast enough for a relatively small piece of orbital debris to inflict severe damages on a spacecraft or satellite.³ Majority of the world's population rely on satellite technologies and applications every day.¹¹ Indeed, satellites have many essential uses, including communications, photograph and mapping, remote sensing and Geographic Information System (essential to geographical studies), weather forecast, global positioning system, and the defense industry.¹² When pieces of space debris increase, they pose a great threat not only to the orbital paths of these satellites, but also to their operational span, due to possible collisions.¹¹

In the same vein, debris also affect safety of humans in space. The prospects of more human presence in orbit are becoming more realistic every day. Organizations are planning space missions for tourism. For example, both SpaceX and Virgin Galactic intend to begin private passengers' flights to space in early 2020s decade.¹³ Moreover, current manned missions such as the International Space Station (ISS) are always considered to be at risk of debris situations. Unsurprisingly, NASA records that the ISS has made 3 collision avoidance maneuvers in 2020 alone.¹⁴

Asides the effects of debris in space, there is also direct danger to Earth. Large items from space can re-enter Earth successfully without totally burning up in the atmosphere, and this can result in nuclear contamination of Earth's surface.^††^,15 This danger was made apparent when a Soviet satellite fell to Earth in 1978, scattering radioactive particles over northern Canada; this crash required extensive cleanup of the area.¹⁶ There are other instances of debris falling onto Earth. On April 27, 2000, 3 different places in South Africa experienced space debris crashes.¹⁷ Similarly, on May 13, 2020, a Chinese rocket falling back to Earth uncontrollably may have dropped debris in 2 nearby Ivorian villages.¹⁸ These events force us to consider where the next debris drop will be, perhaps somebody's roof, or in a field of playing kids. There is no doubt that something needs to be done in light of the aforementioned risks.

Current Legal and Policy Framework

Current and Past Actions on Debris Mitigation and Remediation

In the past up until the extant period, multiple guidelines, policies, pieces of legislation, and regulations have been put in place to curb and, if possible, to eliminate space debris. A vivid illustration is Space Debris Mitigation Guidelines, which was developed by the Inter-Agency Space Debris Coordination Committee (IADC)^‡‡ in 2002. The guidelines contain preventative practices designed to control the increase of space congestion in popular orbital regions such as low Earth orbit (LEO) and geostationary orbit to preserve their commercial and scientific value, as well as use of and access to space by future space users.

In the same vein, the United Nations (UN) guidelines on space debris mitigation are also among the key international efforts engaged in a bid to curb this front burner atmospheric issue of space debris. The resolution, adopted in 2007 through resolution 62/117, has 7 guidelines that include: to limit debris released during nominal (spacecraft/orbital stages) operations, to minimize the potential for breakups during operational phases, to limit the probability of accidental collisions in orbit, to avoid intentional destruction and other harmful activities, to minimize the potential for postmission breakups resulting from stored energy and to limit the long-term presence of spacecraft and launch vehicle orbital stages in the LEO region and geosynchronous Earth orbit region after the end of the mission.¹⁹

Impediments to Addressing the Issue of Space Debris Effectively

Remediation of space debris opens up certain legal, technical, and political issues. To begin with, the existing space legal regime and treaties are perhaps the major roadblocks to making progress in sustaining the spatial environment. The treaties are outdated and, in many ways, unable to address the contemporary issues thrown up by space debris.²⁰

Significantly, space debris is not defined, mentioned, or adopted in any UN space treaty or agreement. All of the instruments directly addressing space debris constitute soft laws and do not create binding obligations for states per se. A working definition is essential if there is to be an effective remediation regime. This is because both the Outer Space Treaty and the Registration Convention do not recognize salvage rights in space.^§§ Hence, a space object remains the property of its launching state and it is illegal to move or remove such objects without permission from the launching state. However, with clear definitions as to what amounts to debris as distinguished from space objects, the international community may evolve a regime that supports space debris remediation.

Furthermore, all of the binding international space laws are far too vague to be adapted to address the issue of space debris. Notably, Article IX of the Outer Space Treaty mandates states to refrain from harmfully contaminating the outer space. It, however, does not provide for what amounts to harmful contamination, neither does it establish any mechanism to hold states responsible for a violation of the article.²¹ Furthermore, for dispute resolution under the Liability Convention, “decisions are final and binding only if agreed upon by the parties.”^*** The detrimental effects of the vagueness of international space laws played out in intentional debris creation events such as the Fengyun, with the international community feeling no compulsion to take legal steps.²⁰

The current international space law is also too state centered. It fails to consider the prominence of the private sector in space faring.²² Currently, national laws governing space activities appear to place the law at the call of entrepreneurial innovation.²³ This evolution is exemplified in the U.S. privatization of outer spaceflights through the establishment of public–private partnership contracts.^††† Hence, space-faring companies must be part of a regime that distributes the responsibilities of debris prevention and remediation fairly, and in a manner that reflects the role of the private sector in the space industry.

Also, the 1972 Liability Convention complicated the issue of liability in outer space. This convention was an attempt to define states' liability in outer space to encourage them to behave responsibly there.^‡‡‡ However, its tenets are not straightforward and are hardly enforceable. First and foremost, under the convention, for there to be liability for damages caused in space, the launching state or its agents must be at fault.^§§§ The convention makes no attempt to define what amounts to fault, negligence, and causation in the space context. Second, the major starting point for determining liability is the identification of what objects were involved in a given incident or event.²⁰ While today, governments such as the United States, Russia, and the ESA have the capability to track objects in space,²⁴ the individual abilities of these governments to do this is far from perfect and these tracking systems are not universally accessible.²⁴

Another issue that is closely related to that of salvage rights is that of states' security interests in their space objects and debris. Dual or alternative use is always an issue for both functional and nonfunctional space objects.^25,26 In the context of debris removal, there is the risk of militarization of technologies deployed to clear up debris, since the same technology deployed to remove debris can also be used to incapacitate functional space objects.²⁷ Furthermore, sates might need to provide sensitive information about its debris as part of the remediation process,²⁷ and certain debris may still contain classified industrial or military information of its launching authority.²⁸ These issues can breed suspicion and lack of confidence in removal programs among states, especially in instances of unilateral national implementation of removal technologies.²⁷

Funding of remediation steps is also an impediment that needs to be addressed. This is in recognition of the fact that there are levels to space faring and debris contribution. The justification for this concern is the fact that 3 space-faring nations played major roles in remarkable events leading to the concentration of debris in space. Accordingly, China, United States, and Russia contributed ∼42%, 27.5%, and 25.5%, respectively, of the debris in space.²⁹ The key question within this issue is how does the international community intend to fund debris remediation? Should it be space-faring nations alone? How should the costs be apportioned between states?

Whatever perspective is adopted, the major impediment to space debris removal and prevention is the absence of a binding and comprehensive international law to provide for this. Such a law should consider, among other things, a definition of space debris, the application of environmental law principles in space, a regime for both the removal and prevention of space debris, space traffic management, a clear notion of fault, negligence, and causation.

Addressing the Policy Gaps

Negotiating a Binding International Instrument

Given the uncertainty of the operation of the existing international space laws with respect to the issue of space debris, it is important to bring the debate back to an international forum, and negotiate a framework to govern this aspect. Until the notion of liability, ownership, causation, rules of the road, and negligence are clearly defined in the space context, and space debris is institutionally recognized, there will not be motivation for greater action. Hence, it is recommended that a binding international instrument is negotiated and promulgated to fill in the gaps in the current regime's outlook on space debris. Particularly, the instrument should consider the following.

First, a working, pragmatic, and unified definition of space debris as separate from the notion of space objects. This definition will determine whether states retain control over space debris, whether they are liable for damage caused by debris, and whether they can protest its removal by third parties or demand its return upon such removal.³⁰ Of the existing definitions of space debris, the definition in International Law Association (ILA) Draft Convention on Space Debris definition appears to be sufficiently broad, in that it includes man-made objects that are nonfunctional and not useful, and in whose condition no change is to be reasonably expected. Notably, most accepted definitions of both space objects and space debris are broad and, as such, overlap between them is inevitable. Hence the distinction between space objects and space debris should be limited only for the purpose of evolving a remediation regime. It should not apply to the question of liability, since the object and purpose of the Liability Convention are not debris reduction. Nevertheless, a responsibility to not create debris asides those considered incidental to a reasonable mission can be placed on states. This can be done by making Article IX of the Outer Space Treaty specific to deliberate acts, for example, antisatellite tests. It has also been argued that the creation of space debris itself can be viewed as “fault” within the context of the Liability Convention if the debris was created as a result of failure to comply with codes of conducts in space.

Second, the instrument must also consider improving the Responsibility and Liability Regime under international space law. It should, in particular, elucidate the notion of fault, negligence, and causation with respect to the Liability Convention. Many argue that these notions should be construed in the light of adherence to codes of conduct and space traffic rules.^20,31 Hence, within the framework of the instrument, certain unified codes of conduct and orbital traffic rules should be negotiated as well. Particularly, mitigation regimes, efforts at tracking objects and debris, and guidelines for satellite specifications should be unified.

With respect to space traffic rules, there are unfortunately no such “rules of the road” in outer space. And the adaptation of aerospace regimes is difficult because of the extreme speed with which objects move in space.²⁴ However, international standards for spaceflight also provide one way to reduce the risks of space debris. Collision risk can be minimized if all navigable space objects adhere to the same uniform traffic laws in accessing outer space. The advantage of such a joint international strategy like unified spaceflight standards is that all space objects apply the same rules for avoiding other navigable space objects and non-navigable space objects.²⁴ The instrument should also consider the unification of global objects and debris tracking programs. This is evidently essential to both collision avoidance and the proper administration of the liability regime. Hence, it is suggested that existing and prospective tracking programs should be unified and be made globally accessible.

This standardization should also be extended to technical requirements of satellites and their operation (just like the International Civil Aviation Organization flight standards). Particularly, launches should include both collision avoidance mechanisms and a workable postmission disposal plan. Mc Knight suggests that all satellites >400 km must have propulsive collision avoidance capability.³² Furthermore, although it has been argued that the soft law threshold of 25-year post-mission orbital time should be reduced to 5 years, Mc Knight notes that reducing the 25-year rule to, for example, a 5-year rule, only leads to another 10% reduction over 200 years, which is statistically insignificant.³² Hence, the requirement of postmission disposal plan ought to be mandatory if there is to be a serious mitigation regime. All of these codes of conducts and standardizations can be negotiated through joint efforts of bodies such as the United Nations Committee on the Peaceful Uses of Outer Space (UNCOUPUOS), International Telecommunications Union (ITU), and IADC. And to avoid freezing the suggested regimes, the rules should be subject to periodic revisions.¹⁵

Third, there should be increased adherence to the Registration Convention. The convention allows governmental and nongovernmental operators to report their orbital parameters with their launching states, such that their locations are identified, so that collisions with them and new satellites placed in nonconflicting orbital locations can be prevented.^**** The registration process is a potential path to prevent dangerous practices in outer space. Hence, states should review their registers and provide information on the status of their past and current space missions.

Fourth, the negotiations should also consider the revision of the dispute resolution mechanism under the Liability Convention. Notably, one of the major issues in the settlement of disputes under the current regime is that under the Liability Convention, “decisions are final and binding only if agreed upon by the parties.”^†††† This may be more of an impediment to compliance with whatever binding instrument is introduced. To overcome this issue, the ILA Draft Convention on the Settlement of Disputes in Space provides a variety of nonbinding and binding procedures for the disputing parties to use, and ultimately provides for compulsory third-party dispute settlement and prescribe arbitration as the preferred subsidiary method.³³ Ultimately, it is suggested that the arbitral awards relating to space matters be considered binding and such dispute resolution mechanism should also be accessible to private parties in recognition of their current prominence in the present space industry.

In addition to the above, the instrument must take into consideration the participation of private corporations and individuals in the exploration and exploitation of space. Space-faring companies must be part of a regime that distributes the responsibilities of debris prevention and remediation fairly, and in a manner that reflects the role of the private sector in the space industry.

Adaptation of Environmental Law Principles

Very often, in advocating the importance of the protection of the environment, parts of the environment being a common heritage of mankind have been advocated. Some of such are the oceans of the world. Regarding the oceans, Article XXXVI of the UN Convention on the Law of the Seas states that the seabed, subsoil, and its resources beyond the territorial jurisdiction of states are the common heritage of mankind. This means that such areas are jointly owned by all of mankind, and should be used in a sustainable manner to protect them for the future generations. In this same vein, space is a common heritage of mankind, or it should at least be regarded as such.

In recognition of the importance of space being a common heritage of mankind, a proper legal regime should extend the environmental law principles applicable on Earth to space. This should include the precautionary principle, the polluters-pay principle, the transboundary harm principle, environmental impact assessment, among others. It should be borne in mind that space is a finite resource—at least the part of space that surrounds the Earth.³⁴ For this reason, the clutter of space with debris limits the resources and space available to the use of mankind, while only bringing negative effects.

The precautionary principle

It is the nature of man to use surrounding resources for his own exclusive purposes, without consideration of the effects. However, in realization of the fact that the environment affects mankind as a whole, a culture of sustainable use has been developed. An aspect of such sustainable use is the precautionary principle. In the face of uncertainty regarding the environment or the effects of an activity on the environment, a precautionary approach is to be adopted.

There is a need for this principle to be applied in outer space, just as it is in customary international law. In its simplest form, the precautionary principle requires that “when an activity raises threats of harm to human health or the environment, precautionary measures should be taken even if some cause-and-effect relationships are not fully established scientifically.”^‡‡‡‡ The principle recognizes that prevention is much better than cure, and it is better to act before compelling scientific evidence is available.³⁵ The principle functions to prevent the introduction of a new activity into the environment even in the absence of evidence of the adverse effects it shall have on the environment. Once there is a real possibility of the activity having a negative effect on the environment, then the burden is to be shifted onto whoever seeks to introduce the new activity to show that it shall have no serious effects upon the environment.

It is necessary for the threat to be serious or irreversible for the precautionary principle to apply.³⁶ Although the precautionary principle has been established to form a part of international customary law,³⁷ the application of the principle to outer space is not as direct as in conventional environmental law. At this point, it is important to note that every state involved in space exploration creates debris. Space exploration is impossible without creating an extent of debris.

What is needed is a benchmark of permissible space debris. Therefore, the creation of space debris beyond the permissible extent shall be a violation of the principle once properly recognized and established in an international instrument.

The polluter-pays principle

The polluters-pay principle has been described as “an economic policy for allocating the costs of pollution or environmental damage borne by public authorities” with “implications for the development of international and national law on liability for damage.”³⁸ This principle is contained in Article 16 of the Rio Declaration. However, there is a need to extend this principle to outer space.

In general, whoever causes the creation of space debris should bear the liability of clearing such debris. There is the need for an international instrument that properly allocates liability for the creation of space debris to whoever creates such space debris. This shall serve for a better space environment in 2 ways. First, it shall create a form of deterrence structure, making space farers more conscious of the debris being created. Also, it shall create a veritable avenue to create funds to address whatever space debris are created in an equitable manner.

The need for environmental impact assessment

The requirement of environmental impact assessment is contained in Principle 17 of the Rio Declaration. The principle provides:

Environmental impact assessment, as a national instrument, shall be undertaken for proposed activities that are likely to have a significant adverse impact on the environment and are subject to a decision of a competent national authority.

Before any activity is carried out that is likely to affect the environment, an assessment is to be carried out to know the exact nature of the effect it would have on the environment. The assessment allows the proper consideration of the environment while decisions are being made.³⁹ EC Directive 85/337/EEC⁴⁰ was the first international instrument to grant the principle recognition.

In the space context, any activity that is to be undertaken should necessarily require an environmental impact assessment, to know the exact effects of such an activity on outer space. After such assessments have been made, decisions should then be made in line with the assessments. In the case of the launching of spacecrafts into outer space, the trajectory of the spacecraft and the possible effects must be well considered. In addition, in a bid to prevent the increase of space debris, a disposal regime must be created for the spacecraft. Such a disposal regime shall allow the removal of the craft from outer space after it has served its purpose, or at least to have it moved to a safer part of outer space, to prevent the vicious increase of space debris.

A Removal Regime for Space Debris

With the growing awareness that outer space must be kept clean and safe for future generations, a remediation regime is a step that will be inevitable. This is not limited to mitigation alone, as mitigation will not affect the current amount of debris and will instead only try to manage its progression. Furthermore, due to the predicted Kessler Syndrome, the number of debris will still increase even if nothing is launched. It is, therefore, timely to evolve an orbital remediation plan that takes into consideration active debris removal. And such regime as exemplified in Appendix A1 should consider the following.

First, reregistration of space objects. It is essential for the international community to be aware of the status of past launches—whether the launched objects are still functional or not, and whether any changes can be made to make them functional. Such a review of existing registers will enable the removing authority determine what would qualify as debris and thus can be removed. Such registration will also determine whether states can protest the removal of their launched object by third parties or demand its return upon such removal. By terming any of their objects to be debris, it can also translate to giving consent for the removal of such object, thereby crossing the hurdle of Article VIII of the Outer Space Treaty and Article II of the Registration Convention.

Second, the approach to removal should be agreed upon. The regime must consider which bodies or organizations will carry out debris removal. This requirement is added in recognition of the various interests states have in their debris and space objects, ranging from prospects of alternative use to military secrets that some debris may carry. Although international joint efforts of states in debris removal offer prospects of adequate supervision, the private sector might also have a large role to play. Hence, to provide incentives for private actors in space debris removal, salvage rights can be evolved, such that debris removal may also be open to commercialization. Furthermore, debris removal should follow a planning approach. Particular number of debris should be targeted for removal over a period of time, and these plans should be made taking into consideration the level of risks posed by each part of debris. A commendable step is the list of 50 items that must be removed from orbit. This can be built upon and consolidated in a removal plan.

Lastly, funding is another important issue that must be considered. This is in recognition of the fact that there are levels to space faring and debris contribution. Although the prospects of commercializing debris removal have already been mentioned, the key question within this issue is how the international community will fund debris remediation. Should it be space-faring nations alone? How should the costs be apportioned between states? It is suggested that various methods can be adopted to solve these issues, and these methods should stem from the commercialization of outer space.

To begin with, it is near impossible that a mission will not generate any debris at all. Hence, going by the polluters-pay principle, every launch ought to pay a particular amount for this debris creation. Such a regime can be made possible through ensuring that every launch pays particular amounts in the form of solidarity contribution to the funding of space debris removal. Furthermore, with the prospects of space mining, it is suggested that the UN is placed in a position to be evinced as holding the outer space in common for the benefit of all, thereby encouraging states to empower the UNCOUPUOS^§§§§ in mining matters just as they did in the ITU in orbital space. Therefore, the UNCOUPUOS may now evolve a form of licensing system under which states may acquire licenses to mine particular amounts of land mass on celestial bodies for a particular number of years. Although the first few years of these licenses should be free, at least to give the industry time to attain its balance, subsequent licenses should be acquired for a consideration determined by UNCOUPUOS.^***** The proceeds from these licenses may then be split between footing the running costs of the framework and beneficial projects in outer space.

Conclusion

The problems space debris pose to both Earth and space become more pertinent every day. The current international legal regime regulating space activities has proven to be incapable of handling this issue progressively. The international community needs to come together and undertake certain responsibilities to solve this issue and evolve future plans to prevent the creation of large amounts of debris. Existing efforts at debris mitigation and regime should be unified and standardized, and states should evolve a regime that recognizes space debris as a problem and under which they can be held accountable for the harmful contamination of outer space. The sustainability of outer space is essential to both present and future generations, and if we do not begin to act now, one day we shall be forced to do so, else we lose our gateway to the many possibilities outer space provides to humankind.

Footnotes

Author Disclosure Statement

The authors declare that they have no conflict of interest.

Funding Information

This work was not funded by any organization or person.

APPENDIX

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