Numerical integration and analysis of mars orbital dynamics

Introduction The high-precision numerical ephemeris of Mars is important for its mission planning, spacecraft navigation, and solar system dynamics studies. Methods This study systematically compares the dynamical models employed in the DE441, EPM2021, INPOP21a, and PETREL19 ephemerides and evaluates the contributions of the principal perturbation forces to Mars orbit. Results Over a 30-year integration span, the effects of solar oblateness and the Lense-Thirring relativistic precession lead to the orbital difference on the order of hundreds of meters. Modeling the main asteroid belt as discrete point masses introduces deviations of about tens of kilometers, whereas the ring approximation of the main belt and the model for the Kuiper belt both contribute perturbations on the order of tens of meters. When Mars Express (MEX) ranging, ground-based radar, and VLBI data are combined and weighted based on their average precision, the RMS of orbital differences with respect to JPL/Horizons is on the order of hundreds of meters, whereas orbital deviations introduced by different ring model strategies range from several to tens of meters. Discussion The accuracy of Mars orbit determination is influenced by the precision and quantity of multi-source observations, as well as the strategies for ring model construction.