Orbital propagation challenges and solutions for SST fragmentation services

Space Surveillance and Tracking (SST) operations encompass a wide range of activities, from sensor tasking, orbit determination, correlation and cataloguing of space objects, to in-orbit fragmentation events modeling, reentry and conjunction analysis. In all these applications, accurate orbital propagation plays a prominent role. While the typology of included orbital perturbations and their modeling, as well as the error tolerance of the numerical solver strongly influence both the speed and the accuracy of the propagations, the latter is also impacted by the uncertainties in the knowledge of objects’ physical and geometrical parameters and their evolution. Hence, since each SST application poses different constraints in terms of accuracy and computational efficiency, the capability to tune the settings of orbital propagators depending on the specific application requirements may allow improving the global efficiency of SST services. In this context, this paper presents an adaptive orbital propagation tool integrated in a modular architecture developed for fragmentation event modeling and collision risk assessment. Specifically, to support the definition of adaptability criteria. , the errors deriving from object parameters’ uncertainty and from neglecting some perturbations are compared, thus being able to assess their relative importance. The tool is also applied to propagate the fragments generated by an explosion event simulated using an implementation of the popular NASA Standard Breakup Model, i.e., EVOLVE 4.0. In this respect, two different propagation settings are selected to thoroughly assess the accuracy-computational cost trade-off.