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date: 16 May 2021

Registration of Space Objectsfree

  • Bernhard Schmidt-TeddBernhard Schmidt-TeddGerman Aerospace Center (DLR)
  •  and Alexander SoucekAlexander SoucekProgram Coordinator, Earth Observation, European Space Agency


Space objects are subject to registration in order to allocate “jurisdiction and control” over those objects in the sovereign-free environment of outer space. This approach is similar to the registration of ships on the high seas and for aircraft in international airspace. Registration is one of the basic principles of space law, starting with the first space-related UN General Assembly (GA) Resolution 1721 B (XVI) of December 20, 1961, followed by UN GA Resolution 1962 (XVIII) of December 1963 then formulated in Article VIII of the Outer Space Treaty of 1967, and later specified in the Registration Convention of 1975. Registration of space objects has arguably grown into a principle of customary international law, relevant for each spacefaring state. Registration occurs at the national and international level in a two-step process. To enter and object into the UN Register of Space Objects, the state establishes a national registry for its space objects and notifies the UN Secretary General of all registered objects. The UN Register is handled by the UN Office for Outer Space Affaires (UNOOSA), which has created a searchable database as an open source of information for space objects worldwide. Registration is linked to the so-called launching state of the relevant space object. There may be more than one launching state for the specific launch event, but only one state can register a specific space object. The state of registry has jurisdiction and control over the space object and therefore no double-registration is admissible.

Registration practice has evolved in response to technical developments and legal challenges. After the privatization of major international satellite organizations, a number of nonregistrations had to be addressed. The result was the UN GA Registration Practice Resolution of 2007 as elaborated by the legal subcommittee of the UN Committee for the Peaceful Use of Outer Space.

The complexity of space activities and concepts such as megaconstellations present new challenges for the registration system. For example, the Registration Practice Resolution recommends that in cases of joint launches each space object should be registered separately. Registration of space objects is a legal instrument relevant for state responsibility and liability, but it is not an adequate instrument for space traffic management. The orbit-related information of the registration system is useful for identification purposes but not for real-time positioning information. Orbital data to allow positioning, tracking, and collision warnings need to respond to various requirements of accuracy.

Part I: Legal Framework and the Concept of Registration

Applicable Treaty Law and Its Basic Elements

Historical Development

The principle that space objects should be registered by states was initially formulated in the UN General Assembly (GA) Resolution 1721 (XVI) of December 20, 1961, the first of its kind. This resolution called upon states launching objects into orbit or beyond “to furnish information promptly to the Committee on the Peaceful Uses of Outer Space, through the Secretary-General, for the registration of launchings” and requested “The Secretary-General to maintain a public registry of information furnished in accordance with paragraph 1.”

At that time, the idea was to establish one central worldwide register maintained by the UN. But the UNGA Resolution 1962 (XVIII) of December 13,1963, turned this into a two-step approach with registration in a national registry and in the UN database. The 1963 resolution was the basis for the Outer Space Treaty (OST) of 1967.

The principle of registration of space objects was introduced by the UN shortly after the successful launch of the first satellites by the Soviet Union in 1957 and the United States in 1958 (Diederiks-Verschoor, 1984, p. 11). The procedural aspects and registration obligations were then formulated at the Convention on Registration of Objects Launched into Outer Space in 1975. As of 2018, this convention was ratified by 67 states). The OST had 107 ratifications.

The core of what is referred to as “international space law” is composed of five treaties and a numerous nonlegally binding principles, resolutions, and guidelines elaborated by the UN Committee on the Peaceful Uses of Outer Space (UNCOPUOS) and adopted as UN General Assembly resolutions. The binding treaty comprises the OST and four specialized treaties: the Rescue Agreement of 1968, the Liability Convention of 1972 (LIAB), the Registration Convention of 1975 (REG). and the Moon Agreement of 1979 (MOON). The related principles, resolutions and guidelines are so-called soft-law”; that is, they are not legally binding but are politically binding for the UN member states. They have been developed and adopted in UNCOPUOS and its subcommittees under the consensus principle (Hobe, Schmidt-Tedd, & Schrogl, 2015, p. xxxvi). The consensus principle avoids the necessity to proceed to a formal vote for decision-making. At the end of the negotiation process, consensus is reached when there is no declared opposition by a member of the committee. This procedure allows for a certain flexibility, as it enables those not affected by specific positions to refrain from an explicit committee decision. In principle, treaties are only binding for the parties. Therefore the number of ratifications is important. In contrast, customary international law is considered binding for all states under certain conditions. The basic principles of the OST have arguably reached the latter status after more than half a century of general acceptance. The practical relevance of this status is that the laws are binding even for states that are not party to the respective treaty. This is true for launching states’ obligation to register a space object.

State Parties/Applicability/General Principles

Registration of space objects should be viewed in the context of the core articles of the OST: Art. VI OST on international responsibility of state parties, Art. VII OST on international liability of state parties, and the registration system under Art. VIII OST. This triangle of obligations and rights is interrelated and has to be interpreted as a whole. It is based on the fundamental principle of Art. II OST, that “outer space, including the moon and other celestial bodies, is not subject to national appropriation by claim of sovereignty, by means of use or occupation, or by any other means.” Art. I OST declares that outer space shall be free for exploration and use by all states, irrespective of their degree of economic or scientific development.

Basic Rules of Art. VIII OST (Registration)

Launching State and State of Registry

Art. VII OST establishes a wide-ranging, victim-friendly liability regime in favor of non-space-faring states, or states not involved in launch events. Under the logic of this protective approach more than one state can be the launching state for a given launch event and therefore be liable under Art. VII OST and the Liability Convention. In case of damage, all of the launching states are liable under the principle of “joint and several liability.” This means that the victim can select one or more of the launching states for full reparation (Art. V, para. 1 LIAB). The internal apportioning of the compensation paid by one launching state for the group of launching states has to be dealt with in a second step internally (i.e., between the launching states). This can be based on an agreement between the launching states or on the respective share of responsibility/liability for the damage.

The situation is different for the registration of space objects. There can be only one state of registry. Registration allocates “jurisdiction and control,” which means the exercise of sovereign rights over the space object and, if applicable, any personnel thereof (Art. II, para. 2 REG). This is similar to situations involving ships or aircraft: only one flag is admissible. This exercise of sovereign rights over the object is in line with the principle that outer space is a sovereign-free area because the sovereign rights are limited to the object as such and do not extend to the space it takes up by its presence at a certain position.

The state of registry is selected from the group of launching states of the relevant launch event (Hobe et al., 2009, p. 151ff). This means that “jurisdiction and control” over the space object is focused on one single state out of the group of launching states.

The relevant starting point—the definition of the term “launching State”—is contained in Art. VII OST: “Each State Party to the Treaty that launches or procures the launching of an object into outer space, including the Moon and other celestial bodies, and each State Party from whose territory or facility an object is launched.” This formulation is reiterated by the Liability Convention (Art. I (c) LIAB) and the Registration Convention (Art. I (a) REG) and set out as a definition. There are four criteria that make a state a launching state. The first two criteria are action-oriented: “A State which launches or procures the launching of a space object.” The two other criteria are oriented toward territory and nationality: “A State from whose territory or facility a space object is launched.” For example, if a foreign customer contracts the launch of a satellite through the service of a Russian launch service from Baikonur, there are three launching states in respect to the same space object: Kazakhstan as the national territory, Russia as the party who leases the launch facility and executes the launch, and the state of the launch service customer (“procures the launching”).

In case of nongovernmental launch service customers, it is important to relate the criterion “procures the launching” to the state responsible for this nongovernmental entity. Under the space treaties, there are no space activities independent of any state responsibility. According to Art. VI OST, “States Parties to the Treaty shall bear international responsibility for national activities in outer space . . . whether such activities are carried on by governmental agencies or by non-governmental entities.” Furthermore, it is established that “the activities of non-governmental entities in outer space . . . shall require authorization and continuing supervision by the appropriate State Party.” In case of space activities carried out by an international organization, “responsibility for compliance with this Treaty shall be borne both by the international organization and by the States Parties to the Treaty participating in such organization.”

The application of three of the criteria of the definition of the launching state is straightforward, but the fourth criterion referring to the state that “procures the launching” is more complex in legal terms. The criterion is fulfilled if the launch would not have taken place without the action of the respective state procuring the launch. In case of nongovernmental space activities it does not matter if the state has explicitly authorized the activity or if it failed to authorize the activity according to Art. VI OST. In both cases, the space activity (“procures the launching”) is to be assigned to the appropriate state as defined in Art. VI OST.

Limitations to Launching States

Registration is linked to launching states. Art. II para. 1 REG states: “When a space object is launched into earth orbit or beyond, the launching State shall register the space object by means of an entry in an appropriate registry which it shall maintain.” For cases of two or more launching states, paragraph 2 REG clarifies that “they shall jointly determine which one of them shall register the object.” This limitation to launching states is also relevant for any transfer of registration. In case of a cross-border transfer of ownership of the space object there may be an interest in a corresponding transfer of registration. But the transfer of registration is only admitted between various launching states of the same launch event. In case of a second-hand transfer of the space object to a nonlaunching state, the original launching state remains the state of registry (no legally valid possibility to transfer the registration), but the new owner state is also responsible under Art. VI OST.

A clear distinction has to be made between a delivery in orbit and a second-hand transfer or sale of a space object (e.g., a satellite). In case of a delivery in orbit, the customer fulfills the criterion “procures the launching.” Without the launch contract, by means of which the customer orders and pays for the launch, the space object would not be in orbit in the first place. Therefore this state is a launching state from the very beginning and remains so even if the object is nonfunctional. In case of a second-hand purchase of the object, the buyer does not fulfill the criterion of “procures the launching.” A transfer of registration is only possible in the exceptional case that another of the original launching states acquires ownership of this object.

The law of the sea uses a different criterion for the determination of a link to the registering state, called the “genuine link.” According to Art. 5 (1) of the 1958 Convention on the High Seas, a state “must effectively exercise its jurisdiction and control in administrative, technical and social matters over ships flying its flag.” The 1958 convention was superseded by the 1982 UN Convention on the Law of the Sea (UNCLOS), which requires the existence of a “genuine link” between the state and the ship (Art. 91). In practice this link is more open to interpretation than the definition of “launching state,” which has led to the phenomenon of a “flag of convenience,” which is avoided in space law.

Registration according to OST Article VIII does not establish liability for damage caused by a space object; it is rather the opposite: a state of registry is always a launching state and therefore bears international liability under Article VII.

“Jurisdiction and Control”

“Jurisdiction and control” is a comprehensive legal concept related to state sovereignty and resulting from the act of registration. It has to be used as a whole and may not be split up into its two constituent elements. “Jurisdiction should induce control and control should be based on the jurisdiction” (Lafferranderie, 2005, p. 231). Jurisdiction and control determines the applicable law over the space object and over any personnel thereof. It is important for intellectual property rights, data policy, and the status of persons on board a space object. Practical aspects, such as access to the control center of the space object or technical functions, are only a partial aspect, but not decisive for determining the state having jurisdiction and control. Control in this legal connotation means that the state of registry has “the competence to direct, to stop, modify and correct the elements of the space object and its mission” (Lafferranderie, 2005, p. 230). In view of these practical aspects, states should be motivated to register their space objects to gain the benefits of registration. The relevant legal act in the twofold registration system is being added to the national registry. Inclusion in the UN Register is a public announcement of this act.

UN Register and National Registries

Art. VIII OST assumes that space-faring nations with national space objects will establish a national registry. The binding obligation to establish a national registry is only formulated in the subsequent Registration Convention, namely in Art. II para. 1 REG (Hobe, Schmidt-Tedd, & Schrogl, 2013, p. 251). The general obligation to inform the United Nations, the public, and the international scientific community about space activities is formulated in Art. XI OST. The UN Register provides the basis for sharing the information on the different national registries in a comprehensive database. A few states still deliver registration information according to the earlier UN GA Registration Resolution and not the REG, so the UN Register is structured in two parts, the Resolution Register and the Convention Register.

Registrations according to the UN GA Resolution 1721 B (XVI) of December 20, 1961, are contained in the UN document series with the designation “A/AC.105/INF.-.” Following implementation of the REG, as of April 14, 1977, registration information according has been collected under the designation “ST/SG/SER.E/-.” The UN Register in the formal, legal sense is the collection of the notifications of member states transmitted via diplomatic channels to the UN (Kopal, 2001, p. 373). On this basis, UNOOSA developed a well-structured, efficient online database: “Online Index of Objects Launched into Outer Space.”

Registration Convention of 1975 (REG)

National and International Registries

Art. II REG obliges states launching a space object into Earth’s orbit or beyond to register the space object in an appropriate (national) registry. The UN has to be alerted to the establishment the registry. A failed launch attempt, where the object does not reach Earth’s orbit, does not have to be registered. This is also true for objects reaching considerable altitudes (above orbiting space objects) but not entering into orbit around Earth, such as rockets on ballistic trajectories with their peak altitude hundreds or thousands of kilometers above Earth’s mean sea level.

The contents of each registry and the conditions under which they are maintained are under the discretion of the member states (Art. II, para. 3 REG). However, there is mandatory information that member states must deliver to the UN Register: inter alia name(s) of launching state(s), date and territory/location of launch, the basic orbital parameters, and the general function of the space object. There is no distinction between civil and military objects and registration is also mandatory for the latter. The orbital parameters are indicative for identification purposes. The orbital information is not dedicated to a real-time tracking. For traffic control purposes different tools are necessary. The UN GA Registration Practice Resolution of 2007 has added a number of useful information items to be delivered in addition to the minimum standard of Art. IV REG (Hobe et al., 2015, pp. 401–481).

International intergovernmental organizations (IGOs) have the right to declare acceptance of rights and obligations of the Registration Convention, if a majority of member states are parties to the Registration Convention and the Outer Space Treaty. As a consequence, they can establish a registry for space objects of the organization. Jurisdiction and control in the strict sense is related to state sovereignty, but IGOs can exercise jurisdiction and control to the extent that their member states have transferred rights to the organization. The rule stated in Art. VI, sentence 3, OST, according to which international organizations are the responsibility of their member states, remains untouched.

Elements of Registration and Objects Covered by the Registration

Space objects are subject to registration (Art. II, para. 1 REG). The definition of space objects is contained in Art. I (b) REG: “The term ‘space object’ includes component parts of a space object as well as its launch vehicle and parts thereof.” At first glance, it seems that a launch vehicle can be part of a space object and vice versa. The reason behind this that the state of registry is accountable for everything launched into Earth’s orbit or beyond and that all elements are covered by its jurisdiction and control. The state of registry, being a launching state, cannot deny responsibility for elements that are not useful (e.g., the remaining upper stage reaching an orbit, fairings, and break-ups). On the contrary, a separate registration of an independent element of the launch event is possible (see Zhukov, 1999. p. 75ff, with the example of ISS). The UN GA Registration Practice Resolution even recommends that “in case of joint launches of space objects, each space object should be registered separately” (Recommendation 3. (c)). If a launch service provider launches two satellites for two different clients of two different states, it seems appropriate that each state should gain jurisdiction and control over its space object. This means that, in this case, there would be three registrations: the upper stage by the state of the launch service provider and one registration for each of the satellites. If one of the satellites stems from the same state as the launch service provider, it is nevertheless—for the sake of clarity—recommended that both objects are registered separately.

In the context of registration it is essential to note the responsible state behind the respective space activity (effectively carried out by the owner or operator of the space object). In case of a governmental launch the situation is evident, but in case of nongovernmental actors it has to be specified which state is responsible. In any case, there are no private space activities independent of an appropriate responsible state (Art. VI OST).

Designator or Registration Number

Consensus about mandatory marking of space objects was not reached during Registration Convention negotiations. The usefulness of such markings for better identification after re-entry or in case of loss remained unclear. Nevertheless, the Registration Convention established that if a space object is marked with a designator or registration number, the state of registry must provide the information to the secretary-general of the United Nations (Art. V REG). In practice, a designator widely and commonly used is the reference number given by the Committee on Space Research (COSPAR) to each space object upon launch. This COSPAR designator is regularly included in the information provided to the United Nations under the Registration Convention.

Joint Determination

“Launches involving more than one launching State are no longer the exception; rather, they have become the rule” (Soucek, 2016, p. 32). The Registration Convention, Article II, para. 2, addresses this: “Where there are two or more launching States in respect of any such space object, they shall jointly determine which one of them shall register the object.” Launching states are therefore under obligation to clarify which of them is to exercise jurisdiction and control over the space object because, as noted previously, jurisdiction cannot be conferred upon and exercised by two or more states simultaneously. While the Registration Convention is silent on the question of what such a “joint determination” looks like, practice has shown that there are many ways to reach clarity, the most obvious being the conclusion of an agreement between the launching states. However, sometimes no specific act of determination is concluded and the states in question assume each of them knows and fulfills its respective role.

To give a practical example, joint determination of the state of registry occurs, or should occur, in the case of launch services provided for a customer satellite. The state of the launch service provider and the state of the satellite operator are both jointly and severally liable for any damages caused by the satellite, but only one of them will register the satellite and thus be given jurisdiction and control over the space object. In the example chosen, it will most likely be the state behind the operator that assumes the role of the state of registry for the payload, while the state behind the launch service provider may become the state of registry for the upper stage of the launch vehicle should the latter remain in orbit.

The possibility of joint determination of the state of registry also plays an important role for international intergovernmental organizations such as the European Space Agency (ESA). Such organizations, by virtue of Article VII REG, may under given circumstances declare acceptance of the rights and obligations provided for in the REG and will then be regarded as “launching States” even though they, of course, are not states. Such declaration was made, for example, by ESA in 1978. Every ESA satellite launched has at least two launching states—the ESA itself and the state from whose territory the satellite is launched. In other words, ESA cannot be the sole launching state of its own spacecraft and therefore joint determination is an essential tool to ensure legal clarity in terms of jurisdiction and control.

National Implementation

Registration of space objects is a formal act by states to implement international obligations and to gain jurisdiction and control over the space object. It follows national procedures of administrative law. National registration cannot be carried out by a nongovernmental actor, even though the latter may be required by national law to furnish relevant information to the government. In other words, in the case of nongovernmental space activities, the satellite operator does not enter the space object in a national register. This is the appropriate government’s responsibility, as also established by the REG: “When a space object is launched into earth orbit or beyond, the launching State [emphasis added] shall register the space object by means of an entry in an appropriate registry which it shall maintain (Art. II para.1 REG). Nevertheless, the operator plays an important role in the process of orderly registration and sufficient and timely communication between the nongovernmental actor and the national authority responsible for registration is essential. In general, the obligation to inform the competent national authority is part of the national space legislation or specific regulations. In a number of cases the national space agency acts as the registrar.

Part II: Registration Practice and New Challenges


As noted in Part I, the legal framework for the registration and notification of space objects launched into Earth’s orbit or beyond was developed during the first decades of the “space age” and enshrined in an international treaty that entered into force in 1976. In the decades that followed, questions of the interpretation and application of the Registration Convention arose—and continue to arise. First, as a look into the UN database on registered space objects reveals, registration and notification practice by states and international intergovernmental organizations was far from uniform. Second, the link between the state effectuating the registration (thus obtaining jurisdiction and control) and its conditional quality as a launching state led to practical and theoretical questions about novel ways of launching space objects, the on-orbit transfer of ownership of space objects, and joint launches between two or more states or international intergovernmental organizations.

Registration Practice Resolution

Ever since its entry into force, the Registration Convention lagged behind its predecessors in terms of adherence by states (i.e., ratifications). Although the convention enshrines legal principles and procedures of utmost practical importance—notably regulating the exercise of jurisdiction and control over a space object—and does not contain highly controversial issues, adherence and application left a lot to be desired. There are several explanations for this: First, in the aftermath of the privatization of large international satellite organizations and the launch of the first multi-spacecraft constellations (e.g., Globalstar and Iridium), the first drops in space object registrations occurred. Second, ever since the entry into force of the convention, there was some confusion regarding the technical parameters and the nature and extent of “additional information” to be provided as part of the registration and notification processes. Third, many states did not feel compelled to sign and ratify the convention as long as they did not have their own satellites in outer space. While the latter approach seems understandable at first glance, it should be considered that the Registration Convention offers benefits to state parties who do not have space objects.

Overall, member states called for enhancements to the practice of space object registration and an increase in the number of state parties (Benkö & Schrogl, 1998, p. 60). In this vein, in 2005, the Legal Subcommittee of UNCOPUOS established a dedicated working group mandated to deal with the “Practice of States and International Organizations in registering space objects.” During the three years following its establishment, the working group discussed registration practice with the aim of efficiently tackling the perceived or real weaknesses of the registration system, ultimately resulting in the adoption of UN GA Resolution 62/101 of December 17, 2007, entitled “Recommendations on enhancing the practice of States and international intergovernmental organizations in registering space objects.”

Bearing in mind the benefits to states who became parties to the Registration Convention and observed its provisions, the UN GA made several recommendations: First, states that were not yet parties to the convention should ratify it, and that international intergovernmental organizations conducting space activities that had not yet declared their acceptance of the rights and obligations under the convention should do so. Second, registration practices should be harmonized. To this end, the resolution suggests different types of information to be transmitted to the UN secretary-general on the registration of space objects, such as the web links to official information on the space object or the geostationary orbit location, where appropriate. The third recommendation is tailored to international intergovernmental organizations conducting space activities that have not yet declared their acceptance of the rights and obligations contained in the Registration Convention and joint launches. With regard to the former, the resolution recommends finding ways to achieve registration. With regard to the latter, several recommendations are made: “the State from whose territory or facility a space object has been launched should, in the absence of prior agreement, contact States or international intergovernmental organizations that could qualify as ‘launching States’ to jointly determine which State or entity should register the space object . . . in cases of joint launches of space objects, each space object should be registered separately.” In addition, “States should encourage launch service providers under their jurisdiction to advise the owner and/or operator of the space object to address the appropriate States on the registration of that space object.” The fourth recommendation is addressed to the state of registry and requires the communication of certain additional information in case of change in supervision of a space object in orbit, such as the date of change of supervision or any change of orbital position. Equally, the UN Office for Outer Space Affairs, as the secretariat for space object registration (acting on behalf of the UN Secretary-General), is requested to make a model registration form available and to update its website in order to make the contact details of the focal point public and to make links to the appropriate registries available online. Those requests have since been put in place by the office, which has greatly facilitated the registration/notification processes for states and international intergovernmental organizations and significantly enhanced the accessibility of information via the space object database. Finally, the UN GA recommends states and international intergovernmental organizations to report to the Office for Outer Space Affairs on new developments relating to their practice in registering space objects.

Generally speaking, it became evident that the implementation of an international treaty such as the Registration Convention greatly benefits from efforts to clarify practical questions and provide appropriate guidance. In doing so, the UN GA Registration Practice Resolution of 2007 was an important achievement for the benefit of all space actors and those seeking to enhance legal clarity in regard to states with space objects under their responsibility. Although endorsed more than a decade ago, the resolution continues to provide valuable guidance for states related to their current or future registration practice.

Registration by International Intergovernmental Organizations: The Example of the ESA

Article VII of the Registration Convention opens the possibility for IGOs to declare their acceptance of the rights and obligations provided for in the convention. However, this depends on the majority of the organizations’ member states being parties to the Registration Convention. The first IGO to make such a declaration was the European Space Agency’s (ESA) predecessor in December 1978. Consequently, for more than four decades, the ESA has been registering its space objects and furnishing related notifications to the UN. Only two other international organizations have made such declarations: European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) in 1997 and European Telecommunications Satellite Organization (EUTELSAT) in 2014.

In 2013, the ESA formalized its practice of space object registration by issuing an internal administrative instruction, the first of its kind. The elaboration and implementation of the ESA’s registration policy required clarification of the object and purpose of the REG; relevant state practice, in particular that of ESA member states that are parties to the convention; the promotion of international cooperation (see Article XI of the Outer Space Treaty); the ESA’s internal administrative requirements; and, ultimately, various technical considerations (ESA, 2014). In addition to the policy, ESA introduced a new, flexible and multifunctional registry (the “ESA Space Object Register”), which represents “the authoritative list of all ESA space objects that currently are or ever have been in Earth orbit or beyond.” This registry is closely linked to the agency’s technical space object database “DISCOS” and goes beyond a simple listing of space objects. Instead, each registered ESA space object can at any time be characterized by its current state and position in outer space or its date of re-entry or other disposal. The ESA thus set a standard for registration practice.

It is important to understand that IGOs having made a declaration under Article VII of the Registration Convention are not considered parties to the convention (note that Articles VIII to XII are not “deemed to apply”). Yet, once such a declaration is made, international organizations are equally bound to the convention by force of their unilateral declaration.

Specific Cases

Spacecraft with Separate Planetary Landers

Among the greatly varying types of space objects sent into Earth’s orbit or beyond, there is the class of planetary landers (i.e., rovers or probes designed to land on the surface of a celestial body and conduct in situ research). For this type of spacecraft, the question can be raised whether or not to register it separately from the main spacecraft carrying it to its destination in the solar system. A look into past state practice with regard to registration of such objects reveals that such practice was far from uniform. At times and under specific circumstances, the landers were registered separately from their “mother” spacecraft, while in other cases landers were registered together with their carriers (often by means of a specific entry under “any other information” section of the UN registration form); and at times, planetary landers were not registered or mentioned at all. So, which one of these approaches is most in line with the requirements of the Registration Convention?

Aside from questions of state practice, from a legal point of view parties to the Registration Convention are obliged to register any space object launched into Earth’s orbit or beyond, regardless of its type, designation, or destination. This means that landers do have to be appropriately registered. If the state of registry is the same for the carrier and lander, two separate registrations instead of one common one may appear unnecessary and burdensome. However, the practical implications of the lander detaching from the main space object should be taken into consideration. Indeed the “destinies” of the two objects may differ, for example in terms of lifetime period, location, or functionality, such that each could reach its end of life independent of the other. This leads to the conclusion that separate registration, although administratively burdensome, is useful. Indeed, UN GA Resolution 62/101 of December 17, 2007, recommends that “in cases of joint launches of space objects, each space object should be registered separately.” The same resolution also recommends the transmission of information on each space object such as “any change of status in operation (inter alia, when a space object is no longer functional)” and “the approximate date of decay or re-entry.” To adequately respond to those recommendations, separate registration of carrier and lander units seems necessary or at least preferable. If a separate registration is not pursued, the state of registry of the carrier-lander spacecraft combination should at the very least specify the intended separation and surface landing as part of the overall notification to the United Nations.

If the lander originates from a state different from the one operating (and exercising jurisdiction and control over) the main space object, separate registration may not only be preferable but essential to determine jurisdiction and control. Also, for the purpose of identifying the states liable for damage caused by a space object identification through the state of registry plays an important practical role, as this legal status is comparatively easy to identify. Separate registration by two states would however be conditional upon both such states qualifying as the launching state in relation to the respective part of the carrier-lander spacecraft combination.

Deployment and Positioning in Two Steps

The International Space Station (ISS) is a facility used to release small satellites through an appropriate dispenser into orbit. This modern way of “launching” space objects by means of an orbital platform raises questions also in relation to the respective launching States and, consequently, the state of registry of a space object released into a distinct orbit in this way. In the future, other deployment mechanisms or even the assembly and integration of space objects in outer space (or on and from celestial bodies) may complicate the situation. Such methods show that the traditional and still largely prevailing way of launching space objects by chemically propelled launch vehicles from the surface of Earth may be increasingly challenged in the future.

When a satellite is deployed from the ISS, it can be considered to be launched twice: once from Earth to the ISS and a second time from the ISS into a separate orbit. During its “first” launch, the satellite is carried as a payload by a respective launch vehicle from a given state territory or facility to the ISS. It is later launched from a different—orbital—facility, possibly under a different jurisdiction in outer space. From a legal point of view, the question can be raised of whether the deployment constitutes a launch in the sense of Article 1 lit.(a) REG, and if so, when the satellite should be registered and by whom.

Until the moment of deployment from the ISS, a piggy-back satellite is “not different from a cargo element brought to the station, such as a water canister [or] a science rack” (Soucek, 2016, p. 42). Such objects are not registered separately, nor do they get an international designator or are being notified to the UN. However, they constitute component parts of the original launch vehicle. If not registered separately, the state of registry of the orbital stage of the launch vehicle carries jurisdiction and control over the satellite. An alternative is to register the satellite as a separate space object that will be stored in an orbital facility like the ISS until released at a later point. Or, registration may be carried out upon deployment from the orbital facility (thus taking the “second launch” as the reference launch event). In the latter case, it is understood that even before this “second launch,” international law assigns responsibility, liability, jurisdiction, and control over the object to the launching states of the “first” launch.

Change of Registration/Double Registration/Corrections

In the dynamic world of modern spaceflight, status changes regularly occur in relation to a satellite already in outer space, such as changes in ownership, operation, or supervision. While the transfer of ownership from the previous owner to a new owner is primarily a problem of private, or contractual, law and enjoys freedom of contract in principle, it must not be forgotten that the satellite operations remain space activities to be authorized and continuously supervised by the respective governmental authority. In fact, in several countries a transfer of ownership is conditional upon separate authorization.

While the ownership over a space object may be transferred, the same does not hold true for the qualifications of launching state and state of registry. In fact, a state that has fulfilled one of the criteria of the launching state as defined in the respective provisions of the Outer Space Treaty and Liability Convention, will remain the launching state in respect to the space object regardless of its ownership status under private law.

While this seems understandable from the point of view of third-party liability, it may lead to a seemingly inconsistent situation in terms of jurisdiction and control: the original state of registry retains jurisdiction and control over a space object even if the latter is physically owned and operated by entities acting outside its jurisdictional sphere of influence because the registration cannot be transferred to another state straight away. The possibility of a transfer of registration—and, consequently, of the state of registry—is subject to discussion and considered permissible only under specific circumstances. Prevailing opinion considers this to be acceptable as long as the new state of registry is one of the original launching states of the space object (Hobe et al., 2013, p. 256; Soucek, 2016, p. 42). In this case, transferring the registration would still satisfy one of the cardinal requirements of the Registration Convention, namely that only one of the launching states of the space object may register the latter. The more relevant question, however, concerns the opposite case: can a state that previously had no legal relation to the space object become a state of registry? This is not possible under the Registration Convention. In an attempt to alleviate the situation, Part C of the UN notification form allows for the original state of registry to update information previously submitted and to specify details in relation to a change of ownership and supervision. If done correctly and in a timely manner, this allows a certain degree of visibility to those consulting the UN space object database.

The crux of any such transfer is that the original state of registry continues to warrant the exercise of jurisdiction and control in relation to the “outside world” (i.e., toward external parties), whereas the incoming state will take over the practical exercise of jurisdiction and control depending on the respective bilateral arrangement with the state of registry.

To many states, the situation in relation to on-orbit transfers of ownership (and other status changes, such as a change in supervision or operation) is not entirely satisfactory. Discussions at the Legal Subcommittee of the United Nations Committee on the Peaceful Uses of Outer Space continue to bear witness to the interest of states to reassess possibilities of further enhancing legal clarity in regard to exercising jurisdiction and control over an object that changed its owner while being in space.

In 2013, the ESA transferred the ownership of its geostationary telecommunication satellite Artemis to a private operator in the United Kingdom. On the one hand, this necessitated establishing a contractual relationship to transfer the ownership (i.e., property) of the physical object. On the other hand, it was imperative to clarify rights and obligations between the ESA as the launching state and state of registry of Artemis and the United Kingdom as the state bearing responsibility under Article VI OST for the space activity as carried out by the new nongovernmental owner of Artemis. ESA and the United Kingdom therefore decided to conclude an international agreement arranging for the consequences of the ownership transfer under international law. Finally, ESA as the continuous state of registry submitted the new ownership and supervision status to the UN, in compliance with Article IV, para. 2 REG. This example shows that despite certain open questions a transfer of ownership of an operational satellite can be processed and handled while satisfying both international legal obligations and legal clarity in general terms.

A rather specific problem is the question of disappearance or change of a state of registry. One frequently cited case is the autonomous territory of Hong Kong, today a special administrative region of the People’s Republic of China but previously under the sovereignty of the United Kingdom (until July 1997). While this is an interesting case that requires a practical approach to update relevant space object registrations, it is questionable whether it is good as a general interpretative argument for a transfer of registration to a non-launching state.

New Challenges in the Legal Subcommittee

Multiple Launch Events/Megaconstellations

Recently, concepts of large satellite infrastructures deployed in low Earth orbits have matured such that some may soon reach the level of practical implementation. One of the main drivers of so-called megaconstellations is the increasing saturation of the geostationary orbit and the consequential need to find new ways of ensuring global connectivity for space applications, such as telecommunication services. To attain global coverage and at the same time significantly reduce signal latency requires the deployment of hundreds if not thousands of satellites in low Earth orbit. Such endeavors are promising, but they do raise concerns, for example in relation to on-orbit operation automation and space debris mitigation.

From a perspective of space object registration, the advent of megaconstellations does not raise fundamentally new legal questions. However, it touches upon a variety of practical issues, notably in which intervals to register and notify such large numbers of space objects. It seems hardly conceivable (or administrable) to issue separate registration/notification letters for each satellite of a 750-satellite constellation. Considering that the intention is to deploy megaconstellations in “batches” or groups of satellites (e.g., 8 or 12 per launch), a pragmatic solution could be to register them in batches. This would keep the underlying administrative procedures manageable.

Another practical issue arises from the fact that many such future constellations are the result of truly international cooperation on a private level; that is, they are based on a network of interwoven company relations across different states and jurisdictions. This makes the determination of the relevant launching states and in particular the most suited state of registry not only a challenge, but a necessity. Only through a clear and unbiased attribution of jurisdiction and control will the appropriate handling of programs of such enormous complexity be possible without compromising the international legal framework.

Registration on Behalf and Prelaunch Arrangements

The possibility of “registration on behalf” has emerged and is being discussed by the Legal Subcommittee of UNCOPUOS. As noted earlier, spacecraft launches with multiple launching states are becoming the rule rather than the exception, in particular considering the increasingly diversified launcher market. Therefore, problems occasionally occur with the proper registration of “foreign” space objects launched by a launch service provider registered in a country different from the one of the space object owner or operator (see Lee, 2006, p. 45, for Arianespace launches). Launch service contracts generally include a clause that obliges the customer to properly register its space object with the responsible state. If registration is not executed, there are not many options available to enforce it. If the foreign satellite is not registered separately, the object is part of the launch service provider’s registration of the upper stage. Another discussion around the further amelioration of the registration practice involves the direction of binding prelaunch arrangements about registration in case of multinational launching states.

Concluding Remarks

Registration of space objects is a core element of the jurisdiction and control over a space object and, if applicable, the personnel thereof to one launching state. Registration is a legal act and not a traffic control mechanism.

The implementation of the registration system has developed from the UN General Assembly Resolution (1961), Article VIII of the Outer Space Treaty (1967), the Registration Convention (1975), to the UN GA Registration Practice Resolution (2007). Registration is twofold, namely in registries on the national level and in the UN Register. The UN Online Index is a comprehensive global database.

International, intergovernmental organizations may, under certain conditions, declare acceptance of rights and obligations of the Registration Convention and set up their own registry. The ESA is one such IGO and is actively implementing a comprehensive practice.

New technical developments and business concepts make the implementation of registration more complex. Registration under new, challenging circumstances must takea into account the basic concepts of registration in order to attain an adequate solution. The continuous development of registration practice, based on the respective treaty principles, is remains the subject of discussions in the UNCOPUOS Legal Subcommittee.

Select Documents

Convention on the International Liability for Damage Caused by Space Objects (ratified March 29, 1972; entered into force September 1, 1972) 961 United Nations Treaty Series (UNTS) 187 (LIAB).

Convention on Registration of Objects Launched into Outer Space (ratified January 14, 1975; entered into force September 15, 1976) 1023 UNTS 15 (REG).

Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies (ratified January 27, 1967; entered into force October 10, 1967) 610 UNTS 205 (aka, “Outer Space Treaty”).

UN General Assembly Resolution (UNGA Res.) 1721 B (XVI): International Co-operation in the Peaceful Uses of Outer Space, December 20, 1961.

UNGA Res. 1962 (XVIII): Declaration of Legal Principles Governing the Activities of States in the Exploration and Use of Outer Space, December 13, 1963.

UNGA Res. 41/66: Question of the Review of the Convention on Registration of Objects Launched into Outer Space, December 3, 1986.

UNGA Res. 62/101: Recommendations on Enhancing the Practice of States and International Intergovernmental Organizations in Registering Space Objects, December 17, 2007.

UN Document A/AC.105/382: UN Study on the Application of the Convention on Registration of Objects Launched into Outer Space, March 2, 1987.

UN Document A/AC.105/C.2/L.255: Practice of States and International Organizations in Registering Space Objects, Background Paper by the Secretariat, January 25, 2005.


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Material: UN Registration Template


Registration Information Submission Form (as at 1 January 2010)

This form is available from Please see annex for instructions and definitions. Completed forms are sent as hardcopy through Permanent Missions to UNOOSA and electronically to


European Space Agency, Space Object Registration Policy


Section A. Instructions for completing the form


Download the electronic version of the form from


Reference sources and other resources for completion of the form are available from the above web link.


Review definitions in Section B below and complete the form. If there are any queries, please e-mail


The completed hardcopy form should be sent through official government channels to the relevant Permanent Mission to the United Nations (Vienna) to be formally transmitted to the United Nations.


The completed electronic form should be sent by the appropriate government entity to the United Nations Office for Outer Space Affairs using e-mail

Section B. Definition of terms

Part A: Information provided in conformity with the Registration Convention or General Assembly resolution 1721B (XVI)

Launching State/States/international intergovernmental organization

State of registry/international intergovernmental organization:

The State of registry is the launching State which carries the space object on its national registry of objects launched into outer space. The international intergovernmental organization is an organization which has declared its acceptance of the rights and obligations provided for in accordance with Article VII of the Registration Convention.

Note: In accordance with Article II of the Registration Convention, only one State of registry can exist for a space object. When more than one launching State exists, they should jointly determine which State should register the space object.

Other Launching States:

As defined in the Registration Convention, “launching State” means:


A State which launches or procures the launching of a space object;


A State from whose territory or facility a space object is launched;



The common name/names used to identify the space object.

COSPAR international designator:

Alphanumeric designator established by the Committee on Space Research (COSPAR) for space objects that successfully reach Earth orbit or beyond. The SPACEWARN Bulletin (available at confirms the designators assigned by the World Warning Agency for Satellites on behalf of COSPAR. The designator can also be obtained from the Online Index of Objects Launched into Outer Space at

National designator/ registration number:

Designator or registration number assigned to a space object by the State of registry.

Date and territory or location of launch

Date of launch:

The date of launch of the space object using Coordinated Universal Time (UTC) (also referred to as Greenwich Mean Time (GMT)).

Territory or location of launch:

The territory or location of the launch of the space object. For a table of global launch locations, see

Basic orbital parameters: Basic data on the space object’s orbit around the Earth or a celestial body such as the Sun, Moon, etc. If object is orbiting a body other than Earth, please specify. The parameters are:

Nodal period:

Time taken by the space object to complete one revolution around the body it is orbiting.


The angle relative to the equator of the Earth or celestial body the space object is orbiting. Measured counter-clockwise from the equator.


The furthest distance in the space object’s orbit from the surface of the body it is orbiting.


The closest distance in the space object’s orbit from the surface of the body it is orbiting.

General function:

General information on the space object. Can include mission objectives, frequency plans, etc. If required, please attach text in a separate page.

Change of Status:

The date of the space object’s decay, reentry, recovery, deorbit or landing.

Part B: Additional information for use in the United Nations Register of Objects Launched into Outer Space, as recommended in General Assembly resolution 62/101

Change of status in operations

Date when space object is no longer functional:

The date using Coordinated Universal Time (UTC) (also referred to as Greenwich Mean Time (GMT)) when the space object ceases to perform operational functions for the State of registry.

Date when space object is moved to a disposal orbit:

The date using Coordinated Universal Time (UTC) when the space object is moved into a disposal orbit. See COPUOS Space Debris Mitigation Guidelines for recommendations on disposal orbits,

Physical conditions when space object is moved to a disposal orbit:

The physical conditions when the space object is moved into a disposal orbit. Conditions can include the change in orbit (e.g., +300 km above GSO), passivation of the space object and other measures as recommended in the COPUOS Space Debris Mitigation Guidelines.

Basic orbital parameters

Geostationary position:

Applicable only to space objects in the geostationary orbit. Planned and/or actual location of space object in ± degrees East along the equator from the Greenwich meridian (e.g., for 10.5 degrees West, use -10.5 degrees East).

Additional Information


Address on the World Wide Web for information on the space object/mission/operator.

Part C: Information relating to the change of supervision of a space object, as recommended in General Assembly resolution 62/101

Change of supervision of the space object

Date of change in supervision:

The date using Coordinated Universal Time (UTC) (also referred to as Greenwich Mean Time (GMT)) when the new owner or operator takes supervision of the space object.

Identity of the new owner or operator:

The identity of the new owner or operator of the space object.

Change of orbital position in the geostationary orbit

Previous orbital position:

The previous operational location of the space object in ± degrees East along the equator from the Greenwich meridian.

New orbital position:

The new operational location of the space object in ± degrees East along the equator from the Greenwich meridian.

Change of function of the space object:

The function of the space object following change in supervision.

Part D: Additional voluntary information for use in the United Nations Register of Objects Launched into Outer Space

Basic information

Space object owner or operator:

The entity that owns or operates the space object.

Launch vehicle:

The launch vehicle used to launch the space object into Earth orbit or beyond.

Celestial body space object is orbiting:

The body that the space object is in orbit around, if not Earth (i.e. the Moon, the Sun, Mars, Jupiter, etc.).

Other information:

Information relating to the space object that the State of registry may wish to furnish to the United Nations.