Mitigation of propagation error in interplanetary trajectories

The ability to reliably and accurately perform interplanetary orbit propagation is of crucial importance in several applications in astrodynamics, among which asteroid impact monitoring and mitigation, and interplanetary mission analysis and design are preeminent. When planetary close encounters are involved, numerical propagation is complicated by the amplification of the numerical error in the position and velocity after the encounter. Therefore, the presence of subsequent encounters (for example resonant returns) makes the accurate orbit computation a difficult and challenging task. In this work, we investigate the possibility of reducing the global numerical error by employing regularized formulations of orbital dynamics, such as the Dromo formulation. Test cases are performed both for geocentric hyperbolic trajectories and for a whole interplanetary trajectory with a resonant close encounter. Results show that Dromo, along with the Kustaanheimo-Stiefel formulation, is able to significantly reduce the propagation error with respect to Cowell’s method. In particular, the addition of a time element to Dromo is highly beneficial in containing the error produced by the integration of time.