## 1 Introduction  
Strong and robust maritime security arrangements are required to contribute to the Intelligence, Surveillance, and Reconnaissance (ISR) operations and Maritime Domain Awareness (MDA), which can be accomplished using satellite technologies. This approach based on space information becomes essential for countries in the southern hemisphere, with a sizeable maritime domain to protect in terms of sovereignty and sovereign rights, naval assets, infrastructure, resources, and people [1; 2; 3]. These capabilities can significantly help with resource and biodiversity preservation, economic and environmental sustainability, disaster mitigation, and security at marine, in addition to supporting safety and security at sea [4]. This is especially true for isolated regions such as Australasia [5; 6] and resource-rich regions such as the Gulf of Guinea [7], the South China Sea [8], Micronesia [9], the Argentine Sea [10], the Mediterranean Sea [11] and the Indian Ocean [12], just to name but a few. According to the United Nations (UN), Illegal, Unreported and Unregulated(IUU) fishing is a major factor contributing to more than 90% of global fisheries stocks getting fully exploited, overexploited, or depleted, affecting regions most impacted by climate change. This practice also accounts for one-fifth of global fisheries catches, which can be worth up to USD 23.5 billion per year, making it the third most lucrative business natural resource crime after timber and mining [13]. For MDA, satellites can provide the data for tracking ship movements, i.e., for ISR operations and data for observing the marine environment, such as meteorological and oceanographic conditions. In 2014, the International Maritime Bureau (IMB) estimated that maritime piracy caused USD 16 billion in economic losses annually, mostly as a result of theft, transportation delays, insurance costs, anti-piracy measures, etc. The Distributed Satellite Systems (DSS) involves a set of small satellites working together which can simultaneously cover larger areas and outperform a single large (i.e., monolithic) satellite, which is often more expensive and less effective. DSS has many advantages, including easier design, faster build time, lower replacement costs and increased redundancy [14; 15; 16; 17]. One issue is to keep the formation geometry (required to accomplish the mission) while avoiding inadvertent collisions due to uncertainty in the state of the formation and/or failures. Recent research focuses on various control strategies to address these changes, including the possible adoption of artificial intelligence (AI) techniques [18; 19]. Figure 1 depicts a possible classification and example of Synthetic Aperture Radar (SAR) satellite mission types [20; 21]. The satellite systems are classified into monolithic and distributed satellite systems, and the latter is divided into several possible implementation branches as the constellation (flying far from each other, without relative navigation/control), Formation Flying (close flight, requires relative control) and other options as swarms or hybrid approaches [18]. The implementation of a control law requires communication between the satellites in each formation, i.e., Inter Satellite Links (ISL), in such a way that all the absolute positions are known at least by one of the satellites, while all of the satellites receive all  
Figure 1: A possible satellite system classification, with SAR satellite implementation examples. the relative errors and the center of mass acceleration command in order to implement the associated force. ISL allows for satellite-to-satellite communication on each DSS formation and there are many possible implementations, as shown by [PERSON] et al. [22]. A direct solution is given by the Star topology, where the follower satellites of the formation communicate this navigation state to the chief, and hence the chief can broadcast this information to all the followers, also including its own navigation state and the relative navigation with respect to each of the followers.