模拟偏心打击对行星防御任务中动能撞击轨道偏转的潜在增益  

Potential Gain of Quasi-eccentric Collision on the Kinetic Impact Orbit Deflection in Planetary Defense Missions

作　　者：LEE Kin Thong 王兆魁[1] LEE Kin Thong;WANG Zhaokui(School of Aerospace Engineering,Tsinghua University,Beijing 100083,China)

机构地区：[1]清华大学航天航空学院,北京100083

出　　处：《上海航天(中英文)》2024年第6期46-54,共9页Aerospace Shanghai(Chinese&English)

基　　金：国家自然科学基金资助项目(12373066)。

摘　　要：在小行星动量偏转任务中,溅射效应的存在导致系统动量的“放大”效应。现有研究几乎都集中在航天器撞击小行星几何中心的情境上。通过简要的理论推导表明,当航天器的速度矢量与小行星的速度矢量不平行时,若撞击点位于非几何中心位置,则偏转距离将显著高于几何中心撞击的情况。针对一颗潜在威胁小行星Apophis,开展了动能偏转防御的数值模拟,并对比了最佳双脉冲转移轨道下几何中心与非几何中心撞击产生的偏转效果。结果显示:几何中心撞击的偏转距离平均值为923.59 km,标准差为273.29 km;而非几何中心特定表面撞击的偏转距离平均值为1328.57 km,标准差为48.61 km,相比几何中心撞击效果偏转距离增加43.85%,标准差降低约5.6倍,验证了该方法的有效性。针对小行星姿态信息的不足,采用蒙特卡洛方法生成10万个随机姿态样本进行仿真,以处理不确定性因素。结果表明:该方法不仅验证了理论的可行性,同时有效降低了小行星动能撞击防御任务中的不确定性。在保持撞击条件不变的情况下,非几何中心撞击可进一步放大偏转距离,具有重要的研究价值。In an asteroid momentum deflection mission,the existence of ejecta effects induces an apparent“amplification”of the system momentum.Existing studies predominantly focus on scenarios where a spacecraft impacts an asteroid’s geometric center.However,through theoretical derivations,this paper demonstrates that when the velocity vector of the spacecraft is non-parallel to that of the asteroid,an impact offset from the geometric center can result in a significantly greater deflection distance compared with a geometric center impact.Numerical simulations are conducted for a potentially hazardous asteroid,i.e.,Apophis,to evaluate the kinetic impact deflection by comparing the deflection distances resulting from the impacts at a geometric center and a non-geometric center under an optimized dual-pulse transfer orbit.The results reveal an average deflection distance of 923.59 km with a standard deviation of 273.29 km for geometric center impacts,whereas the impacts on a specific non-geometric surface yield an average deflection distance of 1328.57 km and a standard deviation of 48.61 km.This translates to a 43.85%increase in the deflection distance and approximately a 5.6-fold reduction in the standard deviation,substantiating the method’s effectiveness.Addressing the lack of asteroid attitude information,this study employs a Monte Carlo method to generate 100000 random attitude samples for the simulation to manage uncertainties.The findings confirm the theoretical feasibility of this approach,and demonstrate its potential to significantly reduce the uncertainties in asteroid kinetic impact defense missions.Under invariant impact conditions,non-geometric center impacts amplify the deflection distance,underscoring a considerable research value.

关 键 词：行星防御 非几何中心碰撞 溅射物 超高速碰撞 小行星偏转 小行星几何模型 

分 类 号：V11[航空宇航科学与技术—人机与环境工程]