Space debris is all the ‘junk’ that is floating around the Earth and in space. Over the past decade, the amount of space debris has increased significantly, which can lead to several problems. This article addresses the problem of space debris and discusses the international liability for the damage that it causes.


The launch of the first-ever satellite Sputnik 1, on the fourth of October 1957, marks the beginning of the Space Age. From this moment onward, thousands of satellites and space missions followed. When objects are sent to space – with the exception of spacecrafts – they remain there even when they do not serve a useful purpose anymore. All these ‘useless’ objects that revolve around the Earth are referred to as ‘space debris’. Space debris can be old satellites, rocket stages (used in missile launches), or materials that got lost during space missions. As a result of explosions, collisions and ongoing launches, the amount of space debris has grown considerably. In fact, from the late twentieth century onward more than 29,000 large objects (10 cm and larger), 750,000 medium-sized objects (1cm-10cm) and over 166 million small debris objects (1 mm-1 cm), have materialized from more than 5400 space launches.[1]


While we tend to think that space is enormous, most space junk is located in the Low Earth-orbit, which is approximately between 350 and 1400 km above the surface of the Earth. The objects travel around the Earth with a speed up to 29,000 km per hour.[2] Therefore, space debris poses a major threat not only to the sustainability of the space environment, but also to the functioning of satellites, human spacecraft and the International Space Station.[3] In 2015 for example, three astronauts had to seek shelter as a piece of space debris threatened to crash into the International Space Station. In addition, space debris objects eventually return to Earth. A large number of these objects will burn in the atmosphere, but some larger objects may survive this trip and become a threat to citizens. With regard to the possible accidents that can be caused by space debris, the following legal questions may arise: (1) Who can file a claim for compensation? (2) Who can be held liable in case an astronaut gets injured by space debris? And (3) What is the burden of proof in a space debris accident?


Image 1: The International Space Station (ISS)


The Legal framework of Space Activities: The Outer Space Treaty and Liability Convention
The General Assembly of the United Nations adopted the Outer Space Treaty (OST) in 1967.[4] The aim of the OST was to maintain international peace and preserve space for peaceful exploration and for the benefit of all mankind. The articles in the OST regarding liability are explained in detail in the Liability Convention (LC).[5] The Treaties are legally binding for the state parties under international law, which means that states are bound to act in accordance with their treaty-based obligations.


The scope of parties that wish to make a claim for the damage they suffered is limited to states that are party to the treaties. In addition, nationals of the specific launching state and foreign nationals that were participating in the operation of that space object are both excluded from the scope of eligible claimants.[6] Thus, on the basis of the LC, neither an injured Russian astronaut can file a claim against Russia nor can an injured French astronaut in a United States spaceship file a claim against the United States.


The LC defines who is internationally liable for space objects with the term ‘launching state’, which means: ‘(i) a State that launches or procures the launching of a space object, or (ii) a State from whose territory or facility a space object is launched’.[7] According to this terminology, even if a state has played a very modest role in the space mission – for example, by simply facilitating the launch pad – that state can be held liable. In addition, the LC distinguishes two types of liability, depending on where the damage occurs: absolute and fault liability. Both types will now be examined in the context of space debris.


Absolute liability
Article II of the LC provides a definition of absolute liability:


A launching State shall be absolutely liable to pay compensation for damage caused by its space object on the surface of the Earth or to aircraft in flight.’[8]

In this situation, the injured state will have to prove the national origin of the debris object; consequently, the owner of the space-object.[9] In addition, the injured state must prove that the damage which occurred is a result of the debris object in question.[10] The term ‘damage’ entails direct damages, thus damage caused directly by one space object to another. Nonetheless, since the line of causation is unclear, it is uncertain if indirect damages are included.[11] For example, it may occur that a Dutch debris object collides with an Italian satellite and the latter causes damage to a German space craft. Which state is then responsible?


Fault liability
Article III of the LC concerns fault liability:


In the event of damage being caused elsewhere than on the surface of the Earth to a space object of one launching State or to persons on board by a space object of another launching State, the latter shall be liable only if the damage is due to its fault or to the fault of persons for whom it is responsible.’[12]

Image 2: ‘An artist’s impression of Earth surrounded by space junk.’ Getty Images.

In this situation, the injured state will have to prove the fault of the responsible person of the space debris object. However, there are neither standards for ‘fault’ nor are there ‘standards of care’ or traffic rules for space objects.[13] As a matter of fact, the creation of debris is not forbidden and can be seen as a consequence of the exploration of space.[14] Nonetheless, in recent years the international community has adopted a considerable number of international policies and guidelines with regard to the mitigation of space debris in order to safeguard space and future space missions. The widely supported Space Debris Mitigation Guidelines, created by the UN Committee on the Peaceful Uses of Outer Space, contain measures to avoid and limit the release of debris during space missions and prevent potential break-ups and collisions. Unfortunately, the guidelines are not binding under international law and therefore cannot be enforced before a court. Nevertheless, they could imply a certain standard of care for states in relation to accidents with space debris, namely, a responsibility to control their space objects.[15]


The claim from Canada for the crash of the Kosmos-954 is the only claim that has even been presented on the basis of the LC. In 1978, the Soviet Union satellite Kosmos-954 crashed in an unpopulated area in northwestern Canada. The satellite contained 50 kilograms of uranium 235, which contaminated a piece of land the size of Austria with radioactive waste. However, the case was eventually not settled under the Convention but by diplomatic means according to a protocol between the two states.[16] As described in this article, the terminology of the LC articles is vague and therefore it is ambiguous when a claim can be done successfully. As such, it seems that injured states are hesitant in invoking the LC and will attempt to solve their dispute through different mechanisms.


In the need for internet all over the world, it seems a new space competition has begun. Amazon is planning to bring 3,200 communication satellites into space. In addition, the ambitions of Elon Musk’s company extend even further because his company eventually wants to send more than 12,000 satellites into space.[17] These developments will obviously increase the risk of possible accidents between space objects. In this regard, it seems a matter of time before liability issues will need to be addressed. In order to deal with future disputes regarding the liability in debris accidents, the terminology in the LC’s liability articles will need to be refined by the international community.


Editor: Sophie Horsman



[1] European Space Agency. “Space debris by number.” (January 2018)
[2] NASA. “Space Debris and Human Spacecraft.” (September 27, 2013)
[3] In addition, NASA-scientist J. Kesller, observed that with the increasing amount of space debris, a collision between major debris objects can create a chain reaction with the result that the Earth would be surrounded by a layer of debris. See: D.J. Kessler and B.G. Cour-Palais. “Collision Frequency of Artificial Satellites: The Creation of a Debris Belt.” Journal of Geophysical Research, 83 (1978), p. 2673-2646.
[4] Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies Adopted by the General Assembly in its resolution 2222 (XXI), opened for signature on 27 January 1967, entered into force on 10 October 1967.
[5] Convention on International Liability for Damage Caused by Space Objects Adopted by the General Assembly in its resolution 2777 (XXVI), opened for signature on 29 March 1972, entered into force on 1 September 1972.
[6] Article VII LC.
[7] Article I (b) LC: “The term “launching” includes attempted launching”, and see article I (d) LC: “The term “space object” includes component parts of a space object as well as its launch vehicle and parts thereof.”
[8] Article II LC.
[9] Article VIII OST: “A State Party to the Treaty on whose registry an object launched into outer space is carried shall retain jurisdiction and control over such object, and over any personnel thereof, while in outer space or on a celestial body. Ownership of objects launched into outer space, including objects landed or constructed on a celestial body, and of their component parts, is not affected by their presence in outer space or on a celestial body or by their return to the Earth. Such objects or component parts found beyond the limits of the State Party to the Treaty on whose registry they are carried shall be returned to that State Party, which shall, upon request, furnish identifying data prior to their return.”
[10] Hacket, George T. Space Debris and the Corpus Iuris Spatialis. Editions Frontièrs, Vol 2, 1994. P. 178.
[11] See C. Christol, “International Liability for Damage Caused by Space Objects.” The American Journal of International Law, 74 (1980), p. 362: “(…) it may be anticipated that the convention will interpreted as covering both direct and indirect damage resulting from the malfunctioning of a space object and its components parts.”
[12] Article 11 LC.
[13] Viikari, Lotta. The Environmental Element of Space Law. Martinus Nijhoff Publishers, 2008. P. 72.
[14] Hacket, George T. Space Debris and the Corpus Iuris Spatialis. Editions Frontièrs, Vol 2, 1994. P. 181.
[15] See Joel a. Dennerley. “State liability for Space Object Collisions: The Proper interpretation of ‘Fault’ for the purposes of International Space Law.” EJIL 29.1 (2018), p. 300: these measures may be seen as a certain ‘fault’ standard.
[16] Von den Dunk, F. “Too-Close Encounters of the Third Party Kind: Will the Liability Convention Stand the Test of the Cosmos 2251-Iridium 33 Collision 2010.” University of Nebraska 2010, p. 200, and see articles IX and XIV of the LC in which it is stated that prior to the dispute settlement, states have to find a solution through diplomatic negotiations.
[17] Nederlandse Omroep Stichting. “Amazon wil 32000 satellieten lanceren voor breedbandinternet.” (April 4, 2019), and see VPRO Tegenlicht ‘Ruimtepuiner.’ (March 31, 2019)


Cover Photo: Getty Images.
Image 1:
Image 2: An artist’s impression of Earth surrounded by space junk. Getty Images.

Anne Klein Entink

Anne Klein Entink (1989) is a University Lecturer of International and European Union Law at Erasmus University in Rotterdam. She obtained her master’s degree in International and European Union law at Radboud University in Nijmegen. In addition, she has a special interest in Public International Law and International Space Law.