气动-引力辅助转移轨道研究及在星际探测中的应用

借力飞行是减小星际探测任务发射能量和总的速度增量的有效途径,然而,借力飞行前后,探测器速度矢量转角的变化往往受到借力星体体积、质量等因素的影响,而不能达到理想的要求。若在借力飞行中引入气动辅助变轨,即气动-引力辅助转移(AGA),则这一问题可以得到有效解决。现通过对AGA转移轨道的分析,给出了AGA转移轨道设计的拼接条件,此拼接条件是对AGA转移轨道进行设计和分析的重要准则。同时还以探测Ivar小行星为例,提出了一种将绘制等高线图和圆锥曲线拼接相结合的设计AGA转移轨道的方法,并给出了设计探测Ivar小行星转移轨道的参数。数值计算表明:AGA转移方法不但可以降低远程星际探测任务的发射能量和总的速度增量,而且可以找到更多的探测机会。

Study of Aerogravity Assist Transfer Trajectory and Application in Interplanetary Exploration Missions

In interplanetary exploration missions, the gravity assist is an available approach for reducing launch energy and total velocity increments. The gravity assist technique is limited, however, by the turn angle of hyperbolic excess velocity vector that can be affected by a flyby body. This turn angle depends on the size and mass of the planet and so on. One method of circumventing this turn angle limitation is to use aerogravity assist (AGA). In this paper, we analyzed the AGA transfer trajectory and presented the patching conditon for designing the AGA transfer trajectory. This patching condition is the basic principle for designing and analyzing AGA trajectory. Then, taking the exploring Ivar asteroid as an example, an approach of designing AGA transfer trajectory with plotting contour map and patching conic was presented, and the trajectory parameters for exploring Ivar asteroid were presented. The calculation demonstrates that AGA technique not only decreases the launch energy and total velocity increments but also finds more exploring opportunities.