太阳帆绕地球周期轨道研究

Solar Sail Periodical Orbits around Earth

地球同步和太阳同步卫星在各个领域有着广泛的应用。静止轨道是一种特殊的地球同步轨道,轨道资源有限。利用化学推进或电推进可以实现轨道高度不同的同步轨道,如悬挂轨道,但需要消耗较多的燃料,工程上无法承受。本文考虑利用太阳帆实现地球同步和太阳同步轨道。太阳光压力在轨道平面内沿拱线方向,选择光压力与平面的夹角使得轨道平面的旋转速率与太阳光同步。研究表明,设计合适的半长轴和偏心率可以使得轨道旋转速率与地球自转速率一致。假设太阳光与赤道平面平行,可以得到准静止轨道,太阳帆将在传统静止轨道的附近运动,星下点的经度将在一个固定值附近振动。实际上太阳光是与黄道面平行,黄道面与赤道面之间存在夹角。考虑黄赤交角的情况下,太阳帆将在一定纬度和经度范围内运动。适合于对某个区域进行长期观测任务。

Earth-synchronous orbits and Sun-synchronous orbits can be applied in all kinds of fields. Geostationary orbit is a special Earth-synchronous orbit and geostationary orbit resource is limited. Utilization of chemical propulsion or electrical propulsion can generate stationary orbits of different orbit altitudes, which will consume unbearable propellant in engineer practice. A solar sail is proposed to implement Earth-synchronous orbits and Sun-synchronous orbits in this paper. The solar sail is aligned to guarantee that the orbit plane rotates synchronously with the sunlight. The results show that this is possible by designing the solar sail and selecting the orbit parameters. With the assumption that the sunlight is in the Earth equator, the solar sail can evolve in a quasi-stationary orbit with its ground track moving around a point. In fact, the sunlight is in the ecliptic plane. Considering the angle included between the Earth equator and ecliptic plane, the ground track of solar sail will be an area suitable for long time observation.