基于新近重力场模型MRO120D的火星探测器轨道仿真与分析
Simulation and Analysis of Martian Explorer Orbits Based on the New Gravity Field Model MRO120D

针对火星探测器在轨运行时间的问题，利用动力学方法和最新火星重力场模型MRO120D，对220 km和150 km初始轨道高度的火星探测器进行轨道仿真分析.结果表明，考虑重力场模型二阶位系数C₂₀时，探测器在220 km轨道高度能够在计算时间内长期稳定地运行，不考虑该系数的探测器在轨运行时间不足40 d，说明位系数C₂₀是稳定轨道的重要因素.在相同条件下，探测器在150 km轨道高度运行时间不足18 d，说明大气阻力效应对低轨探测器的影响较大.在满足相关科学任务的条件下，建议初始轨道设计在220 km以上，以此获得较长的在轨运行时间.
To understand the influence of Mars probe orbit on its orbiting time, this paper makes simulation and analysis of the orbit of a Mars probe with a preliminary orbit height of 220 or 150 km, using a dynamic method and the recent Martian gravity filed model MRO120D. The results show that the probe that considers the two-order coefficient C₂₀ of the gravity field model runs stably in the set cycle of orbiting time at a height of 220 km and that the probe with no consideration of C₂₀ stays on the orbit for only 40 days, indicating a crucial role of C₂₀ in orbiting time. With the same method and data, the probe with a height of 150 km lasts less than 18 days. This result indicates that Martian atmosphere has a major effect on low Mars satellites. In order for a probe to orbit for a long time, we propose a height of more than 220 km for Mars satellites when other scientific objectives are satisfied