A Comprehensive Comparison of Global Space Situational Awareness Data and Information Sharing Systems

With the explosive growth of large-scale satellite constellations, the number of on-orbit spacecraft has surged, leading to more frequent fragmentation events and a deteriorating space environment. This situation has significantly increased the probability of collisions. As a result, the sharing of Space Situational Awareness (SSA) data and information has become a key development trend for enhancing the sustainability and safety of the space environment. To improve the assessment and prediction of potential conjunction events for the protection and governance of the increasingly crowded space environment, major space-faring nations are rapidly advancing the construction of SSA data and information sharing systems. This article analyses the current state and challenges of global SSA data and information sharing systems by comparing the United States' TraCSS system, the European Union's EU SST framework, and other SSA data sharing initiatives. It also examines recent collision avoidance incidents and on-orbit fragmentation events, ultimately proposing targeted recommendations to mitigate risks and promote a safer space environment.