Sanya D. Kishwar* and Shivansh Nangia**

This is a two-part blog. The authors discuss the ramifications of space debris as an environmental pollutant in the first part. The second part discusses the international legal framework with recommendations. 

Key Words: Cosmos 2251 – Iridium 33 – Liability Convention – Space station – Stray satellites 

Part I: Ramifications of Space Debris as an Environmental Pollutant


From the failed launch of the Thor-Ablestar that got dismantled over Cuba and ended up butchering the famous cow “Ruhina” to the relatively recent crash of a Chinese March 3B rocket Booster which crashed into a village, spreading toxic fumes and destroying homes, accidents caused by falling space debris are in abundance. These unfortunate events are not rare occurrences. In May 2020, debris from a Chinese Rocket’s failed re-entry fell into villages on the Ivory Coast. More recently, in July 2022, debris crashed into the Indian Ocean. Though the exact repercussions of the crash are yet to be quantified, subsequent pieces of said debris were found dangerously close to villages in Borneo. With over 630 explosions, collisions, and other unplanned events since 1957, more than 100 million objects have been categorised as space debris that can cause serious unforeseen damage.

The UN Space Debris Mitigation Guidelines of the Committee on the Peaceful Uses of Outer Space has set the first internationally accepted definition of space debris as “all man-made objects, including fragments and elements thereof, in Earth orbit or re-entering the atmosphere, that are non-functional”. Johnson argues that the definition also encompasses leaking fuel and coolant droplets since they can be extremely dangerous at such high speeds. We face a plethora of legal and social problems when it comes to space debris management. The lack of a universally agreed upon definition of environmental pollutant makes it difficult to classify which forms of space debris could be classified as a pollutant. The fact that we have not yet formed cohesive jurisprudence on debris management adds to the problem. As of now, a majority of the debris management task is left upon the Earth’s atmosphere, which naturally pulls orbiting debris downward and incinerates it into the thicker lower atmosphere. However, increasing carbon dioxide levels are lowering the density of the upper atmosphere, which may diminish this effect, creating an increased need for human intervention in space debris management.

Ramifications of Space Debris on the environment 

With an increasing quest for scientific breakthroughs, nations across the globe are constantly competing. Space research is one such area that attracts both developed and developing countries. Unlike earlier times, space research is being commercialised, and according to the Global Risks Report published in 2022, this has created crowding and competition in space. For comparison, one could understand the Low Earth Orbit (‘LEO’) as a market space and the satellites (communication, expeditionary or otherwise) as the product choices available for consumer consumption. Here, consumer consumption could be equated with the benefits satellites provide, such as communication, television and broadcasting, and weather prediction. The more satellites a country launches, its control over the space market grows stronger. With an increasing number of developing countries launching satellites successfully, developed countries have also resorted to competitive multi-satellite launches. With more than one satellite being launched at one time, the LEO is now heavily crowded. Many of these satellites fail to return to the Earth’s surface and stray in the LEO or the orbit and enter the non-LEO zones. In both cases, satellites are contaminants in space. The United States Space Surveillance Network has tracked more than 15,000 pieces of space debris measuring larger than 10 cm and 20,00,000 pieces measuring between 1 and 10 cm. As of 2021, they estimate a potential presence of a million debris pieces lesser than 1 cm in size. The Department of Defence’s Space Surveillance Network has tracked 27,000 particles of “spacejunk” till 2022. 

A 1 cm object can penetrate the pressurised crew module of a space station, kill the crew and cause the station to break up, pierce the window of a craft, and disable or destroy a satellite. In contrast, 0.5 mm fragment can puncture a suit and kill an astronaut. Given the threats such space debris particles pose, it is important to determine the scope and extent of the launching state’s liability. This is particularly important when such objects contribute to pollution in both space and Earth’s atmosphere. For instance, when the Russian navigation satellite Cosmos1934 collided with debris from another Russian rocket body, both objects belonged to the same state. The impact of the collision was such that it created thousands of new debris pieces in space. These debris pieces pose a potential collision threat to future objects launched by Russia as well as other countries. In this case, since the satellite that was destroyed and the object that caused its destruction belonged to the same country, the question of liability and compensation was in the backseat. In 2009, a US-owned satellite Iridium-33 collided with a defunct Russian military satellite, Cosmos 2251. This collision resulted in hundreds of pieces of larger, traceable debris and is considered the worst satellite breakup, the effects of which continue to be felt. Situations like this demand determination of liability of the launching state for harm sustained by space objects of other states. Internationally, this is governed by the Convention on International Liability for Damage Caused by Space Objects 1971 (Liability Convention). 

Article II of the Liability Convention recognises an absolute liability of the launching state to pay compensation for the “damage caused by its space object on the surface of the earth or to aircraft flight.” However, the Convention is silent on the liability of the launching state when it’s space object damage another natural space object, with resultant debris particles causing potential threats in both outer space and Earth’s atmosphere. The authors suggest that besides requiring one state to compensate the other, there should also be a determination of state responsibility and consequential liability for creating pollution. Closely investigating the reasons for such collisions would be helpful in concluding the proportion of each state’s contribution and resultant liability to clean up such pollution.  

Article III of the Liability Convention stipulates liability determination on the basis of fault when the damage is caused by space object of one launching state to a space object of another launching State elsewhere than on the surface of the Earth or, to persons or property on board such a space object. However, it is important to note that the Convention does not clarify whether space debris pollution would be considered a fault in space for the purpose of liability determination. Moreover, the liability for damage is confined to space objects and person or property of other States. The consequential damage to outer space environment due to collision of space objects is not addressed under this provision.

In the absence of liability for abandoning the satellites after they become defunct, the number of stray satellites is increasing. This leads to an increased risk of their collision with active satellites, other stray satellites as well as natural space objects. Such collisions contribute not only to pollution in terms of emissions but also in terms of light pollution. Intense light is emitted by such collisions that would not have happened but for the stray satellites. This causes hindrances for scientists who are observing space from the Earth. 

Besides being a space contaminant, a stray satellite also acts as a creator of more such contaminants. Stray satellites without any way to steer onto a steadier orbital path have an increased chance of careening into other orbiting objects, be it another satellite or a piece of debris. This catalyses the cycle of debris generation. Furthermore, the remains of such objects, after a collision, might get accumulated in the lower space sphere, with the possibility of their escape into the upper atmosphere, resulting in reduced capacity of the upper atmosphere to absorb the harmful solar radiations. From a commercial perspective, such continued competitive launching by countries would result in a potential monopoly on the LEO, which would severely hamper the continuation of scientific research for the sole purpose of benefit of humankind. 

In summary, even though space debris has not been recognized as an environmental pollutant, its interaction with other objects could potentially lead to pollution in outer space as well as on the Earth surface. Therefore, it is important to have a legal regulation in place in this regard. In the next part, the authors will critically analyses the existing legal frameworks on outer space while presenting recommendations to reduce the impact of space debris pollution.

* Lecturer, Jindal Global Law School, O. P. Jindal Global University, Sonipat, India.

** Student, LL.B. (Hons.), Jindal Global Law School, O. P. Jindal Global University, Sonipat, India.


Dr. Atul Alexander*

Keywords:   ARSIWA – Chicago Convention – Countermeasure – Force Majeure – UN Charter

Recently the United States (U.S) shot down the Chinese High Altitude Balloon (HAB) in the sovereign airspace of the U.S. According to the U.S. Secretary of Defense Llyod Austin, the HAB was deployed to carry out surveillance activities in the continental U.S. The incident forced the Secretary of State Anthony Blinken to comment how China had breached the fundamental principles of international law and also postponed his diplomatic visit to China. 

In the aftermath of the incident, several scholars argued how China violated international law; this post explores how both U.S and China breached international law obligations. The Chinese claim that the balloon was used for civilian purposes for undertaking scientific research. Moreover, it contended that it could not prevent the balloon from drifting because the westerly wind movement influenced the balloon’s scheduled route. As China puts it, the infringement was a case of force majeure. It is without a doubt that the incursion of the balloon tested the boundaries of international law. 

Force Majeure Exception

The initial Chinese statement claims that as the balloon was in distress, it was entitled to enter the U.S. sovereign airspace. Since the balloon was used for civilian purpose (as per Chinese reports) it does not enjoy sovereign immunity.  In terms of distress, Art. 23(1) of Articles on Responsibility of States for Internationally Wrongful Acts states (ARSIWA) states in substance that- the wrongfulness of the act committed by a State is precluded, if the act is due to force majeure, that is, the occurrence was because of irresistible force or unforeseen event, which is beyond the control of the State. This is a scenario wherein the State is compelled to act in a way inconsistent with the international law obligation incumbent upon it. To invoke force majeure, there are three fundamental requirements; (a) the act must be brought because of the irresistible force of nature, (b) it has to be beyond the control of the State, and (c) it becomes materially impossible in the circumstances to perform the obligation. Assuming that the balloon drifted because of the westerly winds, it certainly fits into the first requirement. It can be said that the movement of the balloon is beyond the control of the Chinese authorities, and hence, it became materially impossible for China to fulfil the international law obligation. 

The U.S. could assert that China was in breach of the principles under the general international lawand the Convention on International Civil Aviation 1944 (Chicago Convention). State practice reveals that force majeure applies in situations of actual impossibility and not difficulty of performance plea. The International Law Commission (ILC) commentary provided examples of distress to include cases of aircraft entering the airspace of other states because of loss of control or weather. The exception to the said rule is when the State invoking the exception has actively contributed to the material impossibility and thereby accepted the risk of the occurrence of force majeure. As Michel Bourbonniere and Louis Haeck point out, “The overflight of sovereign territory by a state aircraft can be justified by reasons of distress or force majeure as an exception to the principle [that state aircraft cannot flyover the territory of another State…without authorisation.” However, according to Article 8of the Chicago Convention, pilotless aircraft are required to get special authorisation from the contracting State over which the aircraft is flown, this is also espoused by the U.S. statute wherein the federal government maintains exclusive sovereignty over U.S. airspace, and foreign aircraft require permission to navigate.

One of the annexing agreements under the Chicago Convention is the International Air Services Transit Agreement, the agreement provides for multilateral exchanges with regard to the first two freedoms of the air with regard to schedule air services. The Convention and the annexing agreement meant that each State recognized the other’s right to fly through national air space. Although China has denounced the agreement on 11 December 1946, through its note of 3 June  1997, the Chinese Ambassador, stated that the agreement ‘applies to Hong Kong at present, will continue to apply to the Hong Kong Special Administrative Region with effect from July 1997.’ Also, by the note dated 8 December 1999, it applied to the Macau region. Moreover, the freedoms mentioned in the Transit Agreement are with respect to scheduled air services. Accordingly, the applicability of rights under the Transit Agreement in this case becomes questionable.

The Legality of United States Actions

As per Article 1 of the Chicago Convention, every State has complete and exclusive sovereignty over airspace above its territory. Annex VII of the said convention defines an aircraft as “any machine that can derive support in the atmosphere from the reactions of the air other than the reactions of the air against the earth’s surface.” The definition under the Chicago Convention’s Annex VII includes object lighter or heavier than air and powered or unpowered balloons. Further, paragraph 2.2 of Appendix 5(Annex II) of the Chicago Convention states how an unmanned free balloon used exclusively for meteorological purposes shall not be operated across the territory of another State without appropriate authorisation. Further, paragraph 2.3 provides that authorisation is to be taken prior to launching the balloon if there is a reasonable expectation…that the balloon may drift over the airspace of another State. It is evident from the existing fact that China didn’t get prior authorisation from the U.S.

After the downing of the KAL 007 on 1 September 1983, members of the ICAO assembly adopted Art 3 bis to the Chicago Convention, wherein, if there are reasonable grounds to conclude that an aircraft is being used for any purpose inconsistent with the purpose of the Convention, instructions are to be given to the aircraft to end the violation. In doing so, a State may resort to appropriate means according to relevant rules of international law. In essence, Article 3 bis precludes States from using weapons against intruding aircraft. It is widely agreed that Art 3 bis is a codification of customary international law. Also, the point to be noted is that Art. 3 bis does not intend to modify the rights and obligations of the State under the UN Charter. Therefore, the U.S could attempt to make a valid justification for the use of force under Art. 51 of the UN Charter.

Article 51 permits States to use force for self-defence in case of an armed attack against it.  In the Oil Platforms Case (2003) between Iran and U.S, the International Court of Justice (ICJ) articulated the jurisprudence on ‘armed attack’; accordingly,  it expressed, in exercise of the right of individual self-defence, States have to prove that attack against it is of such a nature to be qualified as an ‘armed attack’ within the meaning of Art. 51. Literal reading of Art. 51 would indicate that an armed attack has to be essentially kinetic in nature. Hence, self-defence taken devoid of a previous act of an armed attack (in a kinetic sense) is untenable. 

Further, to trigger Article. 51, the requirement of proportionality, necessity and immediacy are to be fulfilled. Even if the Chinese Balloon entered U.S. airspace, it did not use force, a prerequisite to trigger Article 51 and to press into application the proportionality and necessity threshold. The ICJ has shed light on the nature of self-defence in the NicaraguaCase (1986); in para 74, the ICJ observed, ‘whether the response to the [armed] attack is lawful depends on observance of the criteria of the necessity and the proportionality of the measures taken in self-defence’. 

The other reasoning which the U.S may place is anticipatory self-defence, which came into the limelight after the famous Caroline Incident (1837). If the U.S asserts anticipatory self-defence, the defence is shaky because as per Pentagon’s admission, the HAB was “traveling at an altitude well above commercial air traffic and [did] not present a military or physical threat to people on the ground.” If the U.S claims are unjustifiable, this may amount to a blatant breach of a jus cogens norm of prohibition of the use of force; wherein the U.S could incur state responsibility under international law.  At most, this incident could be a case of espionage at par with States deploying submarines conducting spying in the territorial waters. As I have argued previously, espionage per se doesn’t violate international law obligations. In a diplomatic sense, it is implied that States spy on one other. The absence of legal justification under international law can characterise the U.S action as a countermeasure. Countermeasures are justified under certain circumstances, if carried out to make other States cease the violation of international law. However, for invoking countermeasures, there are a plethora of strict requirements like a prior internationally wrongful act of the responsible State against the injured State, notification and offer to negotiate with the responsible State etc. Therefore, the purpose of countermeasure is restoration and not retributive. But the U.S. is yet to make any unambiguous statement on countermeasure. 

* Assistant Professor, The West Bengal National University of Juridical Sciences (WBNUJS). The author would like to thank Prof. (Dr.) Sandeepa Bhat B. for his valuable comments.