Long-Term Orbit Predictions for Low-Lunar Satellites Unker the Influence of Gravity and Solar Radiation Pressure

摘要

In this paper, the long-term effects of lunar gravity and solar radiation pressure on low lunar orbits are investigated. Closed-form solutions for the orbit problem are known to exist for the case of gravity-induced perturbations. Here, these solutions are applied to high degree and order lunar gravity field models. This solution is valid for a zonal gravity field and near-circular orbits. It valid for a zonal gravity field and near-circular orbits. It predicts the geom-etry of frozen and periodic orbits. The most recent lunar gravity field model, LP75G, predicts no pos-sible polar frozen orbit at 100 km altitude; how-ever, frozen orbits are possible at slightly higher alitudes or inclinations around 90 degrees. Results for periodic orbits whow that the eccentricity grows too large before completion of a period, therefore a delta-V strategy is analysed here. Furthermore, the long-term orbit prediction problem is extended to include perturbations, caused by direct solar radi-ation pressure, for which a closed-form solution can also be established. This solution involves no eclipses and a simplified force model. Analytical re-sults show small but noticeable effects on the satel-lite's lifetime. A prolongation of up on to fifteen days in lifetime can be reached. The model is validated by numerical integration.