卫星轨道偏心率的变化特征及其对轨道寿命的影响

The Variable Feature of Orbital Eccentricity and its Influence on Orbital Lifetime

轨道偏心率的变化极其重要,它是制约各类(不同高度)空间飞行体轨道寿命的关键因素之一。对于地球低轨卫星,主要受大气耗散作用的影响,而对环月(或环火星)低轨卫星,主要受非球形引力位中奇次带谐项的影响,会出现变幅较大的长周期变化,从而导致近星点高度h_p在一段时间内有明显的下降趋势。对大偏心率轨道和高轨道,第三体的引力作用也会使e出现变幅较大的长周期变化,近星点高度h_p也会有明显下降的现象,这都会影响卫星的轨道寿命,但这一动力学机制与大气耗散机制和非球形引力机制都不相同。即对轨道偏心率的变化特征及其对轨道寿命的影响作一综述。

Variations of eccentricity are very important for satellites orbiting the earth, the moon or Mars. It is one of the key factors determining the lifetime of various space objects （with different orbit height）. In order to fulfill space explorations in a given time, the satellite should have a lifetime long enough. Otherwise, controlling strategies are needed to keep a space object around its orbit at enough height. Variations of pericenter height are necessary for these controlling strategies. For low-earth orbit satellites, their eccentricities are mainly affected by dissipative atmosphere drag. For low-moon （or low-Mars） orbit satellites, the eccentricity is mainly caused by odd zonal coefficients in non-spherical gravitation of a central body. Long-period variations with larger amplitude will cause obvious decline of the pericenter height hp in a segment of time. These long-period variations have close relations with ｜J2l-1/Jl｜ and orbital inclination i. However, these relations are quite different for the cases of low-moon （and low-Mars） orbit satellites orbit satellites. For orbits （around the earth, the moon or Mars） with large eccentricity or high attitude, they will be affected by perturbations from the third body. These perturbations will also cause large long period variations in eccentricity and the decline of pericenter height hp, and affect the lifetime of satellites. However, the dynamical mechanism of these perturbations is different from those of dissipative atmosphere drag or the non-spherical gravitation. This paper describes in detail such variations in eccentricity e and their roles in determining the lifetime of satellites.