International space law constitutes a branch of public international law that has evolved and expanded as a result of scientific and technological advancements. In this context, the significance of outer space in connection with cyber operations—ranging from civilian communications and navigation to military operations—is increasingly recognized and undeniable. Space-based systems, including communication satellites, sensors, the Global Positioning System (GPS), and a range of other capabilities, form an integral part of global cyber infrastructure. The importance of this issue stems from the fact that the ongoing expansion of activities in outer space is closely tied to the growing utilization of cyber capabilities. In this regard, cyber operations may target space-related cyber infrastructures—particularly satellites—or exploit them for purposes such as data retrieval or alteration, disruption of space communications, interference with uplink or downlink signal transmissions, partial or total destruction of a system’s software or hardware, or manipulation of satellite control mechanisms. Notably, cyber operations designed to access satellite-based sensors may be employed to disrupt information gathering, gain access to collected data, or distort such data for military or economic purposes.

The growing threats posed by cyber operations targeting space assets have given rise to new legal challenges within the domain of space activities that warrant thorough examination. As humanity’s relationship with outer space and cyberspace remains in its formative stages, the development of appropriate legal frameworks can meaningfully shape this interaction for decades to come. As we move toward a new era of space exploration and development, ensuring the security and reliability of these systems will be essential to realizing the full benefits of these technologies. At present, neither customary international law nor existing treaty regimes explicitly address cyber operations, particularly in the context of outer space. However, the absence of specific legal rules does not imply that states are free to engage in cyber operations without restraint. Through interpretative tools, it is possible to extend the existing legal principles and norms enshrined in space treaties to the realm of cyber operations.

In this regard, the absence of a global consensus on the application of international legal norms to cyber operations, coupled with the lack of a coherent and uniform state practice, has elevated the Tallinn Manual 2.0 as one of the most significant recent efforts toward regulating cyberspace—including space-related activities. This document provides a legal framework for addressing the challenges that arise in this domain. Tallinn Manual 2.0 may serve as a form of soft law, contributing meaningfully to the adaptation of space law principles to cyber operations. Furthermore, it can be utilized by international bodies—such as the Committee on the Peaceful Uses of Outer Space (COPUOS)—as a reference point in ongoing efforts to regulate cyberspace within the context of space activities.

This study aimed to examine the positions set forth in the Tallinn Manual 2.0 in light of existing rules and regulations under general international law and international space law. In this regard, cyber operations must, first and foremost, be of a peaceful nature and must not constitute an unlawful use of force in violation of Article 2(4) of the United Nations Charter. Additionally, states are obligated to respect the rights of registering states to exercise jurisdiction and control over space objects listed in their national registries. Cyber operations involving outer space must therefore be conducted with full respect for the obligation to refrain from interfering with the peaceful space activities of other states. Finally, states bear the duty to supervise cyber operations, as they may be held internationally responsible either under the principle of strict liability—for the commission of internationally wrongful acts—or under fault-based liability for the obligation to make reparation for damages arising from such operations.

This article seeks to examine legal issues related to cyber operations in outer space based on the existing norms and regulations of general international law and international space law, through the lens of the Tallinn Manual 2.0. In addition to its engagement with the Tallinn Manual 2.0, the article extensively references various core space law treaties—including Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies, Agreement on the Rescue of Astronauts, the Return of Astronauts and the Return of Objects Launched into Outer Space, Convention on International Liability for Damage Caused by Space Objects, Convention on Registration of Objects Launched into Outer Space, and Agreement Governing the Activities of States on the Moon and Other Celestial Bodies —which are widely recognized as articulating the fundamental legal framework governing space activities and the principal norms guiding the use and exploration of outer space by states. Accordingly, the article is organized into two main sections: the first addresses foundational definitions and general concepts in the domains of cyberspace and international space law; the second examines the conditions and legal requirements applicable to cyber operations conducted in outer space. The structure of the discussion adopts a comparative approach aligned with the framework of the Tallinn Manual 2.0, and is organized into three thematic parts: (1) “Peaceful Purposes and the Use of Force,” (2) “Due Regard for Space Activities,” and (3) “State Responsibility.” This method of organization not only preserves conceptual coherence with the Tallinn Manual 2.0 but also facilitates a more precise and integrated comparative analysis of the legal obligations governing cyber operations in outer space.