Opinion: Space Power, Space Force, and Space Law


Space is a unique operational domain not only due to its physics, but also due to its legal regime. Although Space Power, the inaugural doctrinal manual of the U.S. Space Force, does not focus on legal issues in and of themselves, it does mention at least one way in which law affects strategy in outer space: “Military spacepower achieves… global persistence by combining the high-altitude perspective of space with the enduring longevity of forward employed spacecraft and an international legal regime which recognizes overflight of any point on the Earth by spacecraft” (pp 21-22). The fact that space is not within any national jurisdiction is but one aspect of the importance of law to civilian and military space activities. Space may be the final frontier, but it is not beyond the law.

This post provides a brief background to the current evolution in space activities and introduces the interactions of legal regimes concerning military space activities. Drawing in part from my chapter in The Future Law of Armed Conflict (forthcoming in the Lieber Studies Series), I describe the types of legal questions animated by military space activities (but make no claim of resolving them in this short piece).

Also, by way of disclosure, I am involved in drafting of the Woomera Manual on the International Law of Military Space Operations. However, the views in this essay are my own and should not be taken as reflecting the substance of the Woomera Manual.

The Revolution in Space Activities

The current evolution of military space power is intertwined with the rise of the “NewSpace” industry. Space activities are an amalgamation of civil, military, and commercial efforts and assets. For example, according to Linda Dawson, in her book War in Space, “[a]t present, around 80% of all U.S. governmental satellite communications traffic, including the military, is conducted by commercial satellite systems” (p 149).

New technologies—such as reusable rockets, small launch vehicles, and small satellites—are significantly decreasing the price of placing satellites in orbit. As a result, a greater number and wider variety of actors than ever before have access to space. There are currently about 2,000 operational satellites. SpaceX, though primarily a launch provider, is entering into satellite communications and is in the process of launching approximately 12,000 satellites of its own. Other companies are planning their own “megaconstellations” of hundreds to thousands of satellites.

Private companies use satellite fleets—whatever the size—to provide a variety of communications services, photo-imagery, and, eventually, real-time video of anywhere on Earth. In an era when Google Maps can be accessed on a smartphone and Planet can provide daily global monitoring, satellite photo-reconnaissance—which used to be the province of an elite club of spacefaring States—has become a commodity with competing private vendors. Meanwhile, the U.S. government is also considering its own use of megaconstellations.

For the foreseeable future, military space activities will be primarily about using, targeting, or protecting satellites. Consider the focus on the regulation of kinetic anti-satellite weapons (ASATs) in the wake of recent tests. The 2007 direct ascent anti-satellite weapons test by China was perhaps the single largest cause of orbital debris. A 2019 test by India threw off less debris but resulted in significant consternation regarding the proliferation of anti-satellite weapons systems. And, most recently, a July 2020 test by Russia of what is believed to be a space-based anti-satellite weapons system further increased such concerns. The proliferation ASATs could not only affect strategy, but also spur the further regulation of the development and use of such systems.

The confluence of these new technologies, actors, and strategies are changing the “givens”—both of what constitutes critical infrastructure and of the capabilities of States and non-State actors. Space power is evolving.

Intersecting Orbits and Overlapping Laws

Considering the implications of these developments on the regulation of military space activities, one can say that while satellite operators watch for intersecting orbits, lawyers are mindful of overlapping regulatory regimes. For example, how do the sources of “space law” interact with the rules governing the use of force or the law of armed conflict (LOAC)? This is a puzzle involving fundamental questions of treaty interpretation, inter-regime conflicts of law, and the survival of obligations during times of armed conflict.

Application of Space Law Treaties

The most significant treaty sources of space law are the 1967 Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies (the “Outer Space Treaty”) and the subsequent Convention on International Liability Caused by Space Objects, the Convention on Registration of Objects Launched into Outer Space, the Agreement on the Rescue of Astronauts, the Return of Astronauts and the Return of Objects Launched into Outer Space, and the Agreement Governing the Activities of States on the Moon and Other Celestial Bodies. The Outer Space Treaty provides the general regulatory framework for human activities in space. The subsequent treaties fill in more precise regulation on specific issues, to varying extents.

To get a sense of how space law and the laws of war can interact, consider the following scenario:

The military of State A launches a satellite (“Sat A”) that, after achieving orbit, begins undertaking maneuvers that put it on a collision course with a surveillance satellite operated by State B (“Sat B”). States A and B have had periodic military conflicts with each other. Up in orbit, State A could possibly change the trajectory of Sat A to avoid a collision. Also, State B could move Sat B, but then it would expend precious propellant and interfere with its ongoing operation, at least for a time. As Sat A approaches Sat B, an object is launched from Sat B and impacts Sat A, disabling the satellite and knocking it into a new vector.

What international laws, if any, are implicated? I use this brief scenario not to provide conclusive answers but to suggest possible issues.

The preamble of the Outer Space Treaty states, in part: “Recognizing the common interest of all mankind in the progress of the exploration and use of outer space for peaceful purposes…”

Preambular language provides context for interpreting the operational language of the treaty. This clause is generally understood in a manner similar to the regime for the high seas: military activities are allowed but they must be non-aggressive.

Article IV of the Outer Space Treaty prohibits the placement of “nuclear weapons or any other kinds of weapons of mass destruction” in orbit, in space, or on any other celestial body. However, the treaty does not prohibit placement in orbit or in outer space of weapons that are not nuclear weapons or WMDs. See, for example, the U.S. DoD Law of War Manual (para and India’s statement after its 2019 anti-satellite weapons test. The Outer Space Treaty does have prohibitions regarding military bases, weapons testing, and military maneuvers on the Moon or other celestial bodies. While Russia and China have supported pursuing a new arms control treaty with a broader prohibition of weapons in space, the United Sates found the 2014 draft of the treaty to be “fundamentally flawed.

Beyond the question of placement of weapons, there is the issue of the actual use of force, which is governed by the UN Charter.

Interaction of Space Law and LOAC

If the scenario described above took place during an armed conflict, then one would also need to clarify the relative roles of LOAC and space law. Can the sources of LOAC, which were developed in relation to terrestrial conflicts, apply in the unique environment of space? The DoD Law of War Manual answers “Yes,” explaining that:

“… law of war treaties and the customary law of war are understood to regulate the conduct of hostilities, regardless of where they are conducted, which would include the conduct of hostilities in outer space. In this way, the application of the law of war to activities in outer space is the same as its application to activities in other environments, such as the land, sea, air, or cyber domains.” (para

Conversely, do space law treaties apply during armed conflicts? The International Law Commission has recently set out a way to approach questions of whether some or all of the obligations of a given treaty survive the outbreak of hostilities in the Draft Articles on the Effects of Armed Conflicts on Treaties, noting that the existence of an armed conflict does not, in and of itself, terminate all treaty obligations.

Resolving Inconsistent Obligations in Legal Regimes  

Assuming that at least parts of the Outer Space Treaty and other sources of space law are applicable during an armed conflict, one would still need to resolve any inconsistent obligations between space law and LOAC. The Vienna Convention of the Law of Treaties and canons of interpretation, such as lex specialis (where the more specific law would govern over the more general law), each provide potential solutions. But these techniques have their limits. For example, the treaty conflict rules of the Vienna Convention of the Law of Treaties are tailored to treaties of the “same subject-matter.” Similarly, in the case of lex specialis, some criticize the application of this canon when the two laws are actually from two different treaty regimes.

Now consider another complicating factor: What if Sat B was not operated by State B, but rather was owned and operated by a private company that sold satellite imagery to State B’s military? Outer Space Treaty Article VI makes State parties internationally responsible “for national activities in outer space… whether such activities are carried on by governmental agencies or by non-governmental entities….” By contrast, Article 8 of the International Law Commission’s Draft Article on Responsibility of States for Internationally Wrongful Acts is based on the direction or control of a State over the non-State actor. Outer Space Treaty Article VI does not require proof of effective control or overall control by the State for the State to nonetheless be responsible for the activities of a non-State actor. Which should apply in this situation of potential armed conflict?


While this short post asks more questions than it answers, a few points are worthy of emphasis.

First, space assets are already significantly integrated into our governmental, commercial, and military infrastructures.

Second, space activities are in an era of rapid change due to a feedback loop of decreasing launch costs, decreasing satellite costs, an increase in the number and type of actors, an increase in commercial ventures and “off-the-shelf” space-related goods and services, and increased contracting by States with companies providing space-related goods and services.

Third, the evolution of space power will be defined in part by this feedback loop.

And, finally, for all the new technologies and doctrinal innovation, the work of international lawyers will be framed by core professional concerns such as treaty interpretation, the resolution of normative conflicts across legal regimes, and the elucidation of classic doctrines such State responsibility and neutrality.

Professor Chris Borgen is co-director of the Law School’s Center for International and Comparative Law. He is past Co-Chair of the American Society of International Law’s Space Law Interest Group and was a core expert  for a proposed Manual on the International Law of Military Space Operations. This article published originally at Articles of War, a publication of the Lieber Institute for Law & Land Warfare at West Point, on September 10, 2020.