### Space-Based Space Surveillance (SBSS)  
The gaps associated with ground-based measurements pave a path for tracking RSO by exploiting space borne measurements [5; 6]. This type of approach is termed space-based space surveillance (SBSS). SBSS is an effective approach due to its capability to offer enhanced performances in terms of tracking accuracy and weather independence, allowing space-borne measurements to provide a broader range of useful observations [7]. In addition, space-based observation systems are not prone to atmospheric scattering, diffraction, turbulence, and aberrations [8]. Historically, radar sensors have been explored for space-borne measurements; however, the challenges associated with size and power consumption have shifted the focus towards optical sensors. Technological developments in optical sensor principles (e.g., coupled charged device (CCD)) [9], complementary metal-oxide-semiconductor (CMOS), and photon counting sensors [7; 10]) have significantly enhanced optical detection performance, demonstrating the ability to track a 3 cm diameter object at a 3000 km range [7; 9]. The precision in state information of the RSO will continue to be pivotal for the future space traffic management (STM) applications. These estimations can be provided using two approaches. **Cooperative surveillance** relies on state estimates from on-board time and space position information (TSPI)/navigation systems (e.g., GNSS, INS) and on the collaborative exchange of information among all other vehicles in the course of a potential collision. Whereas **non-cooperative surveillance** is typically carried out by ground or space-based radar or electro-optical sensors that do not require communication with the observed object. These systems are prone to errors caused by physical phenomena or by the mathematical extrapolation itself. In other words, a non-cooperative scenario is described as an encounter between a host platform and a RSO or possibly a non-cooperative spacecraft, in which only the host spacecraft is capable of preventing a potential collision. On the other hand, a cooperative scenario is described as a scenario in which all the potentially colliding RSO are capable of communicating position data and, if necessary, they can perform manoeuvres to avoid a collision [11]. SBSS has already been attempted in the past; [12] describes various SBSS missions and Figure 2 summarizes different attempts made by different countries for debris tracking. The current space-based SSA systems face issues such as latency and limited coverage, making them unreliable for the future to come. Hence, there is a need for a reliable and sustainable SSA system to fill the gaps in the present. In 1996, the space-based visible instrument (SBV) onboard the mid-course space experiment led to the first SBSS mission [13; 14; 15]. This was followed by the United States Air Force's SBSS mission, also known as the SBSS block 10 satellite. The SBSS constellation aimed to detect and track all space resident objects in orbit around the Earth in real-time [16]. A similar space surveillance mission was conducted by Sapphire, a Canadian satellite for US SSN. It was able to provide accurate measurements in rate track or sidereal track modes [17]. Furthermore, the ORS-5 demonstrator, also known as Sensor-Sat, was launched by the United States with an objective to demonstrate technologies for geosynchronous SSA. The success of the above-mentioned technological demonstrations paved a path to create new evolutionary frameworks for SBSS and to create new profitable pathways for accurate RSO