I’m a PhD student in Aerospace Engineering at Politecnico di Milano, working within the SPIRE Lab. My research focuses on Guidance, Navigation, and Control (GNC) solutions for Distributed Space Systems (DSS) in the context of close-proximity operations. Specifically, primary objectives relate to in-orbit inspection of uncooperative targets.

Due to the growing population of Resident Space Objects (RSOs), such as debris or damaged satellites, in-orbit servicing and removal missions have become critical. However, inspecting these uncooperative objects poses significant challenges: relying on a single spacecraft with monocular vision often limits navigation accuracy due to range observability issues and strict visibility constraints.

To address this challenge, a navigation filter relying on distributed sensing has been developed to enable high-fidelity estimation of the chaser’s relative state with respect to the known target object. This framework simulates a cooperative scenario in which a primary chaser, operating at close range for high resolution image acquisition, is supported by a secondary chaser that provides complementary measurements via Inter-Satellite Link (ISL). By fusing data from multiple viewpoints, the system successfully overcomes the limitations of single-agent sensors.

On going activities aim to extend this scenario to encompass different filtering algorithms. In particular, a centralized joint-state filter and a decentralized architecture leveraging distributed sensing are currently under development and assessment. These approaches are yielding promising results that will serve as bases for further, more realistic developments in the future.

Parallel to the navigation algorithms, I am developing a high-fidelity digital twin of the ISL module tailored for proximity operations. The model implements a hybrid TDMA/CDMA access scheme: this allows the system to manage Time-Division slots for critical data exchange, such as telemetry and GNC states, while utilizing Code-Division for continuous, robust range and range-rate measurements. Furthermore, this module introduces realistic hardware imperfections, such as clock bias, drift and quantization errors.

Regarding future activities, the primary goal is to consolidate the current framework, by integrating the ISL digital twin into the navigation solutions. Subsequently, the focus will shift to the more challenging scenario of unknown target inspection. In this case, both relative state and target’s inertial properties and shape must be estimated, following the well-known Simultaneous Localization And Mapping (SLAM) formulation. By leveraging the multi-view geometry provided by the formation, the scale ambiguity inherent in monocular systems can be resolved, thereby mitigating the drift typical associated with standalone visual odometry.

Click here to view my poster.