Not a Rose by Any Other Name: Dual-Use and Dual-Purpose Space Systems

The dual nature of many space systems is considered by many members of the international community to be a significant issue of concern that can pose challenges to space security, hampering efforts to protect space systems from possible threats. As states work to establish international legal and regulatory frameworks for space security, this duality presents an important block in the road that has states disagreeing on how best to regulate them. The nature of these systems blurs the conceptual boundaries of weapons, making control through restrictions on hardware—the traditional approach to arms control for Earth systems—difficult.

But what exactly are these dual-natured objects, and why are they cause for concern? The term “dual-use” is utilized in space security discussions at the multilateral level to refer indistinctly to two distinct categories of objects, which has caused confusion among members of the international community as well as other stakeholders.

The term “dual-use” is often used in arms control and disarmament discourse. Traditionally, it has been understood to mean objects and technologies that can be used for both military and nonmilitary (civilian or commercial) applications or functions. This definition is deceptively simple, as the understanding of when something may be dual-use is highly dependent on the lens through which it is being analyzed. In this sense, when examining an object from an export control perspective, the term “dual-use” refers to any item that has the potential—even hypothetically—to be used for military applications, including, and particularly, weapons. In the context of nuclear weapons, the term can hold the same meaning as in export control, however, it can also be used to differentiate an asset that has both nuclear and nonnuclear uses (this is also known as dual-capable).

From an international humanitarian law perspective, “dual-use” holds yet another meaning. An object that is used for both military and civilian applications could be targeted if it is considered to be a “military objective” (provided certain conditions are met). In this sense, when conducting a targetability assessment, there is no such a thing as a dual-use object. An object is either a military objective—which could be targetable—or it is not. A military objective is determined by its nature, location, use, or purpose. The criterion of use in this context refers to objects that are actively being used for a military function in the present time, rather than having a potential use, or even hypothetical future use, as is the case in export control.

The road to space security is a long and ever-developing process that started in 1958, in the midst of the Cold War, when members of the international community first expressed their fears of having the geopolitical rivalries of the time extend to outer space, a domain into which humankind had only begun to take its first steps a year earlier, with the successful launch of Sputnik I. These fears led the international community to seek to regulate the use and exploration of this new domain, a willingness that eventually resulted in the entry into force of the 1967 Outer Space Treaty and subsequent international space treaties, negotiated under the auspices of the United Nations. Beyond the international space treaties, which focus primarily on the peaceful uses of outer space, states have sought to address space security concerns explicitly, at the multilateral level, under the banner of the prevention of an arms race in outer space (PAROS). However, despite PAROS having been a prominent issue discussed at the United Nations for over 40 years, the international community has had very limited success in agreeing on space security mechanisms.

Through multilateral discussions, states have managed to find several points of convergence on matters such as what are some key threats to space systems, the applicability of international law to outer space, or the complementarity of non-legally binding measures and legally binding measures to achieve space security. However, the work done by states has also shown that the path to common understanding to ensure the security of outer space has not yet been fully traversed. A major block in the road is the confusion generated by the different interpretations of commonly used terminology, such as “dual-use.” Although the use of this term to denote different types of objects might seem like an innocuous issue, lack of a common understanding on the matter could result in misunderstandings and, consequently, the heightening of tensions, thus impeding the international community’s efforts to address space security concerns.

Concerns with Dual-Natured Objects in Space

As in the disarmament and arms control fields more broadly, when it comes to outer space, the term “dual-use” has been used traditionally to refer to those systems that can be used for both civilian and military functions. Service-oriented infrastructure, such as global navigation satellite systems (GNSS), Earth observation (EO) satellites, and communication satellites, is a prime example of this. These satellites are capable of carrying out a vast array of tasks that make many everyday services accessible. For example, satellites make safe navigation possible in the air, on land, and at sea. Satellite services also allow humankind to have access to high-speed internet, carry out electronic financial transactions, as well as control and manage certain critical infrastructures and services, such as energy grids, water, and transportation.

These same satellites are also used in the context of defense and security, to carry out military functions, and to support military operations on Earth. GNSS can be used to track troop movements and for ground, air, and maritime navigation of armed forces. EO can be used to gather intelligence, surveillance, and reconnaissance data that enables militaries to identify adversary capabilities, as well as to locate and identify potential targets. They also provide information to facilitate disaster relief and humanitarian assistance operations. Communication satellites can provide encrypted communications and improve situational awareness, which allows military forces greater mobility. While solely military satellites can have these capabilities and can provide these services only to militaries, dual-use systems—which can be operated by militaries but also by civilian or commercial actors, and they service civilians and militaries alike—have become increasingly prevalent.

The military applications of these satellites are generally understood to be compliant with the “peaceful purposes” principle enshrined in the Outer Space Treaty, which has become customary international law. Under this principle, outer space shall be used only for “peaceful purposes,” which is commonly understood to mean “nonaggressive” or “nonhostile” rather than “nonmilitary,” thus allowing for the development and use of space systems that have military applications.

This civilian-military duality, which gives these space systems the qualifier “dual-use,” is a characteristic shared by many space systems that multiple states have highlighted as an issue of concern capable of threatening space security, due to the role these systems can play in fostering mistrust among space actors. Members of the international community worry that the operational ambiguity of these objects could contribute to raising tensions among states. More specifically, states fear that military services provided by these dual-use assets could make them targetable by an adversary even when they also provide civilian or commercial services. This fear has only increased in recent months in the face of declarations by certain states that they would consider dual-use satellites, even when operated by a commercial actor, a legitimate military target that could potentially be the object of an attack.

The abovementioned dual-use objects are not the only dual-natured systems that raise concerns for the members of the international community. Multiple states have also expressed worries about technologies that are developed for commercial or civilian objectives of an entirely benign nature—such as on-orbit servicing (OOS) and refueling, or active debris removal (ADR)—but that due to their characteristics and capabilities (for example, having a robotic arm to repair satellites, or a harpoon or laser to remove space debris from orbit) could be repurposed to harm other space objects. These objects are distinct from dual-use systems, as they are developed to serve a solely nonmilitary and nonaggressive purpose. However, the potential they have to be repurposed to act as counterspace technology—that is, as an asset that can be utilized against another space object or a component of a space system in order to degrade or damage it in some way (in a reversible or irreversible manner), so as to gain advantage or superiority against an adversary—has caused many observers to include these objects under the “dual-use” umbrella. A more accurate term, introduced recently in space security multilateral processes and used increasingly to refer to this second category of objects, is “dual-purpose.” 

Two Distinct Categories: Dual-Use and Dual-Purpose

The distinction between dual-use and dual-purpose was introduced for the first time during the second session of the Open-Ended Working Group on Reducing Space Threats through Norms, Rules and Principles of Responsible Behaviors established under UN General Assebly resolution 76/231. I proposed this distinction as a way for states as well as other stakeholders, such as the commercial industry, civil society, and academia, to mitigate potential misunderstandings, and enable more objective threat perception and mitigation, while also fostering benign applications of space systems.

The terms “dual-use” and “dual-purpose” proposed here are based on language already existing in international humanitarian law, specifically in the regulations applicable to targeting, where “use” and “purpose” are two of the criteria to determine whether an object is a military objective and, thus, targetable. As highlighted above, military objectives can be identified by their nature, location, purpose, or use. Purpose and use are the relevant identifiers in this case. “Use” is concerned with the present function of an object, while “purpose” is concerned with its intended future application. The definitions of “dual-use” and “dual-purpose” proposed here are similarly distinct: 

• Dual-use space systems can have a military and security function, as well as a civilian or commercial one, either simultaneously or alternating. (Alternate use is sometimes known as dual-capable.) They can be operated by the military, even to provide services to civilians (examples include certain GNSS services). And they can also be operated by civilian or commercial actors, even to carry out military functions, as militaries can sometimes outsource certain services, particularly for satellite communications or remote sensing. These objects are known as “dual-use” precisely because they actually—in the present time—serve both military and civilian functions, regardless of whether they only served one function in the past (as was the case of GPS, the first GNSS service, which started as a military system that later became accessible to civilians). The concern expressed by states regarding these objects stems from the possibility that they may be targeted due to the militarily relevant services they provide.
• Dual-purpose space systems are designed to fulfill a benign objective (such as debris removal or on-orbit servicing), but they could potentially be repurposed to harm other space objects. They are generally operated by civilian entities, as well as commercial actors. Dual-purpose objects are in principle not intended to perform military functions directly—although they may provide some form of support to military satellites through on-orbit servicing, for example—and they are not intended to perform aggressive or hostile actions against other satellites. However, their characteristics or capabilities—such as the possession of a robotic arm or their maneuverability, for example—have raised concern that these objects could be repurposed to be utilized against another space system. It should be noted, however, that the capabilities themselves are not the reason these objects are perceived as a threat. In this sense, the term “capability neutral” has been used by some states to highlight that the capabilities of dual-purpose objects alone pose no danger to space actors. It is the challenge of discerning an operator’s intent when utilizing these assets that has led many to perceive the assets themselves as a threat, even when they are used in a relatively transparent manner. 

Although dual-use and dual-purpose objects are different, they can share characteristics that could, in theory, cause them to qualify as both dual-use and dual-purpose at the same time. For example, a dual-use satellite with maneuvering capabilities could be repurposed to act as a counterspace weapon by causing it to maneuver so that it collides with another satellite. In practice, however, such situations would be relatively unlikely as it would be impractical and very costly to use a satellite in this manner.

Implications of the Distinction Between Dual-Use and Dual-Purpose

It is important and necessary to distinguish between dual-use and dual-purpose systems, as these are two distinct categories of space systems. The nature and concerns that stem from the utilization and applications of each are different; thus, their treatment and regulation should also differ.

There are multiple reasons why distinguishing between dual-use and dual-purpose is necessary and will positively affect space security. First, considering these two distinct categories of space systems under the dual-use umbrella has proved confusing and counterproductive in efforts to negotiate mechanisms to address threats to space systems and ensure space security. When states use only the expression “dual-use,” it is often difficult to ascertain the nature of the space system they are referencing, the threat that it may pose, and, therefore, how best to mitigate it.

This lack of clarity also negatively affects commercial operators of technologies that could be considered dual-purpose, such as ADR, OOS, and space objects capable of conducting rendezvous and proximity operations. Grouping these technologies with true dual-use systems has contributed to their (inaccurate) association with military systems, which has led some observers to think that these technologies could contribute to the weaponization of outer space.

A clear distinction between dual-use and dual-purpose objects would aid in demystifying these technologies, as well as the operations that can be conducted with them and the services they provide. In this sense, classifying objects in these two distinct categories would result in reduced threat perception and increased transparency and confidence among space actors and stakeholders. 

Moreover, establishing regulations for dual-use and dual-purpose objects in a separate manner would also be simpler and potentially lead to a more secure space domain. To be effective, regulations need negotiators to have a shared understanding of the issue they seek to address, and the objective they aim to achieve with the regulation, neither of which exists when all dual-natured objects are included under the “dual-use” umbrella. As highlighted above, on the one hand, dual-use objects raise concerns because the services they provide to militaries—generally to aid their operations on Earth—could lead some to deem these objects targetable. However, it is generally understood that a dual-use object would not be used as a weapon to harm other space systems. On the other hand, dual-purpose objects have been deemed as concerning by some due to the nature of their capabilities, which could be repurposed—weaponized—to damage or destroy other space systems. Potential limitations that could be applied to the military applications of dual-use objects should not necessarily extend to dual-purpose systems, as the latter are not necessarily of a military nature and such limitations could restrict beneficial, and entirely peaceful, applications of dual-purpose space objects. Similarly, certain restrictions placed on dual-purpose objects could potentially hamper services that dual-use systems provide—including critical infrastructure services—if both categories of objects are regulated in the same manner under the “dual-use” banner.

A clear separation of these objects avoids this, and it also makes the application of existing laws and regulations a clearer and less confusing endeavor. Namely, in the case of tensions or in an armed conflict, the application of the laws of the use of force as well as international humanitarian law would be more straightforward, thus affording greater humanitarian protection. In this context, the consequences of targeting a dual-use or a dual-purpose asset are likely very different, and these differences must be taken into account when considering principles such as necessity, proportionality, or precautions. 

In the case of dual-purpose objects, possible consequences include the disruption (either temporary or permanent) of the services they provide: It could prevent the repair or refueling of a satellite in the case of an on-orbit servicing asset, for example. Moreover, depending on the method used to target the asset, there could be additional consequences, such as the creation of debris if kinetic force were used. In the case of dual-use objects, consequences could be greater, and more deeply felt by people on Earth, as they provide many services of critical importance for life on Earth, such as the ones highlighted above. 

A distinction between dual-use and dual-purpose objects highlights that threats to space security do not stem merely from the capabilities of space systems but also from the manner in which they are utilized and the intent behind their use. This is particularly relevant when assessing the threat perception of dual-purpose objects, which may possess certain “repurposable” capabilities. The mere fact that these capabilities could be repurposed to harm another object does not necessarily signify that they will; thus, their normal operations should in principle give no reason for alarm. However, deviations from such normality—such as a nonconsensual rendezvous and proximity operation of an OOS satellite—could be cause for concern, as they could be indicators of intent to harm.

The separation of dual-use and dual-purpose into two different categories of objects by states and nongovernmental entities, such as civil society, commercial industry, and academia, would aid in reducing the lack of clarity caused by the existence of these objects. This distinction would be a useful transparency and confidence-building measure that would dissipate the perceived ambiguity traditionally associated with these objects, thus contributing to the creation of a more secure and prosperous space domain.