火星探测微流星体环境模型及风险预测

Model and Impact Risk Assessment of Meteoroid for Mars

微流星体是自然存在的微型天体.在太阳系空间范围内,微流星体的主要起源为彗星及小行星.在地球至火星的空间范围内,微流星体的飞行速度范围为24.13~42.2 km·s-1.高速飞行的微流星体一旦撞击火星探测器,将有可能对探测器造成毁灭性的损害.本文基于太阳神探测器的观测结果及彗星轨道观测统计结果,针对火星探测,分别建立了地火转移段及环火飞行段的微流星体环境模型,并基于有限元离散方法建立了火星探测任务的微流星体碰撞风险预测方法.设计了-个虚拟火星探测器,分别对其在地火转移段及环火飞行段的微流星体撞击通量进行了分析.结果显示,在探测器有效任务期内,探测器正面受微流星撞击次数约为背面的10倍.根据本文模型计算结果,将探测器顶板铝合金蒙皮的厚度增加至0.7mm后,在整个任务周期内可将探测器正面受微流星体撞击出现击穿损伤的风险降低为每平米7次.

A Meteoroid is a small rocky or metallic body in the space. In the solar system, most meteoroids are fragments from comets or asteroids. In the space between Earth and Mars, the speed of meteoroid ranges from 24.13 km·s-1 to 42.2 km·s-1. The high speed meteoroid may cause catastrophic damage to Mars probes. In this paper, the meteoroid environment models for the flight from Earth to Mars and the flight in the near-Mars orbits are established respectively. The meteoroid environment models are established based on the zodiacal light observations by the space probes Helios I and II, and the observed orbital parameters of comets. The assessment method of meteoroid impact risk for the Mars orbiter mission is also established using the finite element method. A Mars probe with relative anomalous shape is proposed, and the meteoroid impact risk of this assumed Mars probe is predicted for demonstration purpose.