空间物体椭圆轨道假设下碰撞通量计算与分析

Calculations and Analysis on Impact Fluxes for Space Objects under Assumption of Elliptical Orbits

利用陈氏模型,不依赖于气体动理论和泊松统计假设,对近地空间物体环境中环绕飞行航天器碰撞通量的计算问题进行了研究。分析运行在椭圆轨道上的空间物体通过指定区域的4种情况,推导得到碰撞通量关于物体穿越统计区域所用时间的表达式。文章亦对圆轨道和椭圆轨道假设作了比较,并以铱星86为例,讨论了两种假设情况下空间物体对它的碰撞通量。结果显示,随着统计区域厚度的增加,椭圆轨道假设下的碰撞通量从约为圆轨道假设的4倍减小到1.4倍;圆轨道假设下,计入统计的空间物体数量随着统计区域的厚度变化产生的波动较大,椭圆轨道假设下的统计目标数量在区域厚度取5 km时可达圆轨道的60倍。

This paper studies the impact fluxes calculation for the orbiting space objects via the Chan＇ s model which does not invoke either the kinetic theory of gases model or the Poisson distribution function. Four cases are discussed for the space objects on elliptical orbits passing through a thin spherical shell surrounding the spacecraft. The paper also compares the circular orbit assumption with the elliptical assumption. The satellite Iridium 86 is used to estimate the impact fluxes under both assumptions. It shows that the ratio of the impact flux between the elliptical orbits case and the circular case decreases from about 4 times to 1.4 times as the thickness increases. The statistical number of the objects gets a big fluctuation as the increased thickness in circular case. The elliptical case is 60 times more than the circular case when the shell＇ s thickness equals to 5 km.