Cooperative Orbit Determination for Trusted, Autonomous, and Decentralised Satellite Operations

The proliferation of satellite constellations in Low Earth Orbit necessitates a shift away from centralised control, and towards autonomous, decentralised systems for Space Situational Awareness. Crucially, this transition requires establishing trust between satellites in a zero-trust environment, independent of a central authority. Distributed Ledger Technologies offer a resilient foundation for decentralised operations. However, in the domain of space systems, a unified framework that securely integrates consensus-based validation with cooperative Orbital Determination remains unexplored. To address this gap, the Autonomous Cooperative Consensus Orbit Determination framework is introduced, designed for on-board, peer-to-peer validation of orbital data. A novel consensus mechanism, Proof of Inter-Satellite Evaluation, is at the framework's core, and is tailored for resource-constrained systems. Measurement quality is evaluated by using a two-sided chi-squared test on the Normalised Innovation Squared, which is derived from the statistical output of an Extended Kalman Filter. This test is employed to provide a defence against both sensor faults and sophisticated spoofing attacks by penalising data that is either excessively noisy or unnaturally perfect. This statistical evaluation is weighted by a dynamic, long-term reputation score that rewards consistent, high-quality data contributions and penalises untrustworthy behaviour. Simulation results demonstrate that the framework effectively secures the network's distributed ledger by confirming valid transactions and robustly rejecting those from faulty or malicious nodes. The resulting architecture is presented as a viable solution for enabling resilient and autonomous cooperative space systems.