“嫦娥4号”中继星任务轨道确定问题初探

"嫦娥4号"任务将采用着陆器、巡视器和绕飞地月拉格朗日L2点中继星进行月球背面的探测,中继星已先期发射,进入环绕地月L2点的晕(Halo)轨道。在中继星使命轨道动力学模型的基础上,通过相关仿真工作,开展了中继星在Halo轨道上的摄动源量级及影响定轨预报的主要因素分析,结果表明:太阳光压摄动是其主要影响因素。为降低其相关影响,提高定轨精度,在太阳光压球模型的基础上,结合中继星在轨运行特点及其星体结构特点,提出了一种求解光压等效面积的方法。经仿真分析,使用修正后的太阳光压球模型进行定轨求解,速度精度可提升约一个量级。

Preliminary Study on the Orbit Determinationof Chang'e-4 Lunar Relay Satellite Mission

The Chang'' e-4 mission will explore the back of the moon by the lander,inspector and relay satellites that orbit the second Lagrange point(L2). The relay satellites have been launched and entered Halo orbit around L2 successfully. Based on the mission orbit dynamics model of the relay satellite,the perturbation source magnitude of the relay satellite in Halo orbit and the main factors affecting the orbit determination and prediction are analyzed by simulation. The results show that the Solar pressure perturbation is the main factor affecting the orbit determination and prediction. In order to reduce the influence and improve the orbit determination accuracy,a method for calculating the equivalent pressure area is proposed based on the cannon-ball model,combined with the operational characteristics in orbit and the characteristics of the structure of the relay satellite. The simulation results show that the orbit determination accuracy of velocity can be improved about one order of magnitude by using the modified cannon-ball model