by Theodora Liameti, Coordinator of the International Law Research Team

This paper will analyze the notions of “state responsibility” and “international liability”, which appear to have distinct meanings in legal English and are used in several senses in international treaties and judicial practice. Before discussing each notion in the context of international space law, which is considered as lex specialis, this paper will first focus on how public international law and especially on how the International Law Commission (ILC) has dealt with them.

State Responsibility in the context of International Space Law

Starting with the concept of state responsibility, it must be noted that it consists of secondary rules which designate the obligations of the wrongdoer, the legal consequences of an international wrongful act attributed to a State under international law (Shaw, 2014).

Specifically, under Articles 1, 2 and 12 of the ILC’s Articles on State Responsibility for Internationally Wrongful Acts (ARSIWA, A/RES/56/83, 2002), a State is internationally responsible for its wrongful acts -whether those acts consist of an action or omission- whose elements constitute a breach of an international obligation of whatever origin. It is obvious that neither damage nor subjective fault are decisive criteria for a state to be held responsible. On the contrary, the mere occurrence of an unlawful act is enough to incur state responsibility, without requiring intentional (dolus) or negligent (culpa) conduct.

Attribution is an important element that needs to be examined, as a state can only “act” through its organs and its authorized officials. Specifically, conduct undertaken by state organs, whatever their position and their character, is attributed to a state and so is the conduct of persons exercising elements of governmental authority. On the other hand, a State is not responsible for the acts of private individuals done in a private capacity, except for the case when such acts are directed or controlled by it or are later adopted as its own (U.S Diplomatic and Consular Staff in Tehran, 1980, para. 74). A further exception is provided by the principle of due diligence; when a state is required by a primary rule to prevent private acts from resulting in violations of international obligations and fails to do so, responsibility arises. This comes as a logical consequence of the state’s jurisdiction over its territory and its nationals (Nuclear Weapons Advisory, 1996, para. 241–42).

Moreover, when it comes to the legal consequences of state responsibility, the ARSIWA includes the duty to cease and not repeat the wrongful act and the duty to make reparation for the injury so as to “wipe out all the consequences of the illegal act and re-establish the situation which would have existed if that act had not been committed” (Gabčikovo-Nagymaros Judgement, 1997, para. 47). The first and most logical way to do so is that of restoration to the original condition (restitutio in integrum). If that is impossible, the payment of full compensation -usually in monetary form- can be an alternative, while satisfaction may be the most suitable way of reparation of no material damages.

In the context of international space law, the traditional concept of state responsibility is widened. The five UN Space Law Treaties do not regulate the issue extensively. Article VI of the 1967 Outer Space Treaty (OST) is the sole provision referring to the notion and it introduces a general responsibility for “national activities” in Outer Space, whether they are carried out by governmental or non-governmental entities, thus rendering the due care obligation irrelevant. In the absence of more specific provisions, the above mentioned rules of public international law apply, as per Article III OST. The term “national” must be deemed to encompass both activities carried out by nationals and activities undertaken from within the territory of the state in question, to the extent that those activities fall under its jurisdiction (Dunk, 1992). In addition, Article VI goes on to establish a duty for states to authorize and continuously supervise all private activities and ensure that they are carried out in conformity with the provisions of the OST, making them responsible to that effect. This article is a clear example of indirect state responsibility (Williams, 2015).

International Liability for damages caused by space objects 

Proceeding now with the analysis of the second concept, that of international liability, it is important to mention that it is generally seen as a primary obligation of a state to pay compensation or make reparations for the injurious consequences, arising out from acts of persons under its jurisdiction or out of activities within its territory or under its control, suffered by non-nationals, beyond that state’s boundaries (UN.Doc. A/CN.4/510, 2000).  

Especially under the ILC’s work, the concept is closely related to damage and does not stem from the prior violation of any obligation. This means that as soon as damage has occurred -whether that damage arose out of a state’s own “acts” or out of private acts- that State is considered liable and the only kind of legal redemption is compensation. Moreover, prevention of harm is seen as a primary obligation, stemming out of the principle of due diligence, which is imperative while undertaking activities in ultra-hazardous environments, activities otherwise not prohibited by international law (UN Doc. A/56/10, 2001). Consequently, even if maximum care and all reasonable measures have been taken to prevent it, as soon as damage occurs, the duty has been violated and the state in question is held liable and remains obliged to pay compensation.

It is without doubt that the exploration and use of Outer Space involves activities which are inherently “ultra-hazardous”, such as the launching and remote operation of space objects. Therefore, the need to establish a clear liability regime was early identified. Article VII of the OST stipulates that “launching states” are internationally liable for “damages caused by their space objects”. Based on said provision, the 1973 Liability Convention (LIAB) establishes “a victim-friendly” regime, which does not differentiate between lawful or unlawful acts.

According to Article I(a) LIAB the term “damage” should mean any “loss of life, personal injury or other impairment of health; or loss of or damage to property”, caused by a space object. Causation is also an indispensable (sine qua non) condition for the attribution of liability and requires the existence of an obvious, logic and uninterrupted causal link between the damage and the space object. Therefore, only damages emanating from the physical contact with a space object are recoverable, while consequential damages are excluded from compensation (Kayser, 2001).

What is now the legal definition of a space object? The LIAB merely states in Article I(d) that the term includes “component parts of a space object as well as its launch vehicle and parts thereof”. However, the notion should be taken to include any artificial man-made object launched into space or attempted to be launched, including among others space vehicles, facilities, stations, installations and other constructions. Consequently, damages caused by human activities or by man-made objects built in space, do not fall under the scope of the LIAB (Kerrest & Smith, 2009).

Moreover, according to Articles I(b) and I(c) LIAB, the term “launching” also includes attempted launching and refers to: i) a State which launches or procures the launching and ii) a State from whose territory or facility a space object is launched. Procurement can be viewed as referring to the existence of political or/and financial interests in the launching process on behalf of a State, which for example triggers or controls the launch by placing a contract. If one of these criteria applies, the State in question is considered liable with respect to a specific space object, even if built and operated exclusively by private entities. In space law, liability is not linked to ownership, operation or effective control and as required by the maxim “once a launching state, always a launching state”, liability remains forever (Soucek, 2016).

Proceeding now to a short analysis of the two most important Articles of the LIAB, Articles II and III. According to the former, absolute liability, triggered regardless of fault, is established “for damages caused on the surface of the Earth or to aircraft in flight”. The only exoneration is granted under Article VI if the damage has resulted from the wilful misconduct or gross negligence on the part of the claimant state (Mazaroff, 1968). On the other hand, Article III requires proof of fault “for damage caused elsewhere than on the surface of the Earth to a space object of one launching State or to persons or property on board such a space object”.

Lastly, under Article XII LIAB, States found liable have to pay full compensation for the damage suffered, so as to restore the claimant to the condition which would have existed if the damage had not occurred. Such provision is in line with the consequence of international liability as traditionally defined by general international law and analysed above. In practice however, states usually avoid paying compensation by requiring private parties to exhibit an insurance policy as a common condition for the grant of licences (Lyall & Larsen, 2018).


To conclude, liability in the context of international space law arises as a primary obligation to pay for damages caused by space objects, while the secondary rules of state responsibility may be activated when such obligation is not fulfilled. This demonstrates the link between the two concepts and makes clear that liability is closely related to damage, while responsibility arises only in case of space activities being in violation of applicable primary obligations. A further interesting remark is that, especially when it comes to private space activities, under Article VI and VII of the OST, the state to be held liable may differ from that to be held responsible, since the definition of “launching state” may not always coincide with that of “appropriate state”.



[1] Kayser, V. (2001). Launching Space Objects: Issues of Liability and future prospects. New York, Boston, Dordrecht, London, Moscow: Kluwer Academic Publishers.

[2] Kerrest, A. & Smith, L.J. (2009). “Article VII” in Hobe, S., Schmidt-Tedd, B., & Schrogl, K.U (eds.). II Cologne Commentary on Space Law. Carl Heymann’s Verlag.

[3] Lyall, F. & Larsen, P.B. (1018). Space Law A Treatise, 2nd edn. London, New York: Routledge, Taylor & Francis Group.

[4] Mazaroff, S. (1968). Exonerations from Liability for Damage Caused by Space Activities, 54 Cornell Law Review, pp. 71-96.

[5] Shaw, M.N. (2014) International Law. 7th edn. Cambridge: Cambridge University Press.

[6] Soucek, A. (2016). Space Law Essentials Volume I: Textbook. Wien, Graz: NWW.

[7] von der Dunk, F.G. (1992). Liability versus Responsibility in Space Law: Misconception or Misconstruction?, University of Nebraska – Lincoln.

[8] Williams, M. (2015). “Dispute resolution regarding space activities” in von der Dunk, F.G. & Tronchetti, F. (eds). Handbook of Space Law. Cheltenham-Northampton: Edward Elgar Publishing, pp. 995-1045.

International Acts

[1] Articles on State Responsibility for Internationally Wrongful Acts, G.A. Res. 56/83,   U.N. GAOR, 56th Sess., Annex, A/RES/56/83 (2002) [ARSIWA], available here.

[2] Case concerning United States diplomatic and Consular staff in Tehran (United States of America/Iran), Judgement, I.C.J. Reports 1980, available here.

[3] Case concerning the Gabčikovo-Nagymaros Project (Hungary/Slovakia), Judgment, I.C.J. Reports 1997, available here.

[4] Convention on International Liability for Damage Caused by Space Objects, entered into force Oct. 9, 1973, 24 U.S.T. 2389, 961 U.N.T.S. 187 [LIAB], available here.

[5] Report on international liability for injurious consequences arising out of acts not prohibited by international law (2000), UN.Doc. A/CN.4/510, ILC, 52nd Sess., available here.

[6] Draft Articles on Prevention of Transboundary Harm from Hazardous Activities, with commentaries (2001), UN Doc. A/56/10, ILC, 53rd Sess., 2 Y.B.I.L.C, available here.

[7] Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion, I.C.J. 1996, available here.

[8] Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and other Celestial Bodies, entered into force Oct. 10, 1967, 18 U.S.T. 2410, 610 U.N.T.S. 205 [OST], available here.