## 3 Legal Challenges Posed by Mega-Constellations to Existing International Space Law Regime
### Astronomical Interference and Space Debris  
Mega-constellations have exacerbated issues of astronomical interference and space debris. The current measures to mitigate these problems are insufficient. According to [PERSON] (2020) [36], the sheer number of satellites increases the likelihood of interference with astronomical observations and contributes significantly to the space debris problem, posing risks to both existing and future space operations. This makes establishing liability and causation for collision damage very complex, especially for knock-on collisions involving debris. There are no clear international rules on satellite design and operation standards to determine negligence.  
The issue of space debris presents a significant challenge to the current international space law regime. While the Liability Convention attempts to address space debris by defining a \"space object\" to include component parts and launch vehicles, its application reveals substantial gaps. Notably, the definition of \"space object\" does not explicitly encompass non-functional debris, leading to ambiguity about the responsibility for such debris. The exclusion of \"useless\" space debris from the definition limits the Convention's effectiveness in managing the debris problem. Moreover, unidentifiable space debris,which cannot be traced back to a specific space object or launching state, poses a major legal challenge. The Liability Convention's framework does not address the responsibility for such debris, necessitating amendments to the current conventions to tackle these issues effectively. It should also be noted, while calls have been made for the ICJ to provide advisory opinions on orbital light and spectrum pollution, the same should be implemented regarding the determination of responsibility when dealing with debris.  
The increasing number of satellites, particularly with the advent of mega-constellations, exacerbates the space debris problem. The rapid deployment of satellites into low Earth orbits (LEOs) by companies like SpaceX and OneWeb significantly heightens the risk of collisions, potentially triggering a \"collisional cascading process\" or the Kessler syndrome [37]. This scenario, where the density of objects in LEO increases to a point where collisions generate more debris, further increases the likelihood of additional collisions, posing a severe threat to both current and future space operations.  
Furthermore, the failure rate of satellites, especially the cheaper models used in mega-constellations, contributes to the growing debris issue [38]. Even a 5% failure rate in a constellation of 100 satellites results in five new pieces of debris, which can significantly impact the fragile space environment. This is particularly concerning given that Article 9 of the Outer Space Treaty mandates the prevention of the harmful contamination of the space environment. The principles of due regard and cooperation, although not explicitly defined, underscore the importance of international collaboration and mutual respect but also address the aspect of discretion, which has led to controversial interpretation by member states regarding whether their activities qualify for the application of these provisions. [PERSON] and [PERSON] (2019) argue that such cooperation is vital in addressing the collective challenges posed by the increasing commercialization and privatization of space activities [39]. However, the existing legal framework is insufficient to effectively manage and reduce the risks associated with the rising amount of space debris.