Improving international responsibility regime for cyberattacks against critical infrastructure in outer space

Determining whether outer space cyber infrastructure qualifies as critical infrastructure, and whether cyberattacks on such infrastructure that result in harmful interference or damage to terrestrial and space-based systems constitute internationally wrongful acts, or whether they can be regarded as use of force under existing international legal frameworks, and whether the corresponding state responsibility attaches, is a complex challenge. This requires a multidisciplinary approach that blends international space law, cyber law, and general international law, as they were not designed to address the intricate nature of cyberattacks against critical infrastructure in outer space. This gap underscores the need to rethink and redefine the current international law of responsibility to better address these evolving threats. Therefore, this research explores possible international wrongful acts in terms of space cyberattacks, through evaluating the relevant international obligations to prevent and combat cyberattacks against critical infrastructure in outer space, including those from non-state actors, and analyses the difficulties in applying existing legal principles of attribution to such cyberattacks. To improve the international responsibility regime for space cyberattacks, this research advocates extending existing international law, including the prohibition of harmful interference, the principle of due diligence, and non-interference, to enable states to take legal action for damage to space assets, including non-physical harm. While existing legal norms lay the foundation for addressing these threats, dedicated space cyber regulations are necessary, and adapting the due diligence standard would require states to implement practical measures to prevent and combat cyberattacks originating from their territory.