摘要
沙尘暴会对火星表面探测器带来发电量减少、环境温度降低、通信不稳定和仪器污染等方面的影响.为保障我国祝融号火星车的安全运行及未来火星表面探测任务的顺利开展,亟须评估沙尘暴对火星表面探测器的影响.通过系统性地回顾1997~2018年间火星表面探测器(包括着陆器与火星车)对沙尘的响应,初步认清了沙尘对火星表面探测器的影响规律——探测器太阳能电池阵列表面的尘埃以比较稳定的速率积累,而尘埃的沉积速率在沙尘暴期间,尤其是全球性沙尘暴期间会大大加快;同时,受多方面影响,电池阵列表面也会发生具有季节性模式的除尘事件.为规避沙尘暴带来的风险,在美国洞察号着陆器(InSight)的设计阶段就全面评估了沙尘暴对其着陆硬件系统及太阳能电池阵列的影响,并采取了一系列应对措施.洞察号应对沙尘暴的举措为我国未来的火星采样返回任务提供了重要启迪——前瞻性的科学指导是保障工程任务成功实施的关键.通过分析我国火星采样返回任务的初步轨道设计方案,建议未来火星探测器发射的最优窗口为2028年1月左右,以合理规避沙尘暴带来的风险.
The success and accuracy of Entry-Descent-Landing(EDL) for a surface mission to Mars depends on local and regional atmospheric conditions, including atmospheric density, winds, their variations with altitude, and the moment to execute the EDL. Dust storms and their enhanced atmospheric dust loading can affect the radiative heating of the atmosphere,atmospheric density structure, winds, and even the power output of the solar arrays onboard rovers/landers. The assessment and prediction of Martian dust storms are urgently required to serve the currently operating China’s Mars Rover-Zhurong and would be beneficial to China’s Mars mission to return Mars samples in the future. However, it is challenging to accurately predict when and where dust storms will occur on Mars. A detailed review of the effects of dust storms on Mars landers and rovers, which landed on the Martian surface between 1997 and 2018, will allow for a preliminary exploration of the patterns of dust storm effects on rovers on the Martian surface. Studies on the critical effects of dust storms showed that dust accumulates at a relatively steady rate on the surface of solar arrays on rovers, and dust storms, particularly global storms, can greatly accelerate the rate of dust deposition. For example, the global dust storm in 2007 rapidly reduced the dust factor of opportunity and spirit solar arrays by approximately half. Against a background of dust accumulation, most detectors(e.g., solar array) onboard the rover would experience relatively more frequent dust removal events, which may be linked to the speed and direction of the background winds and dust storm transport trajectory. Moreover, the removal of dust from the surface of solar arrays occurs in a seasonally repeating pattern that might accompany the appearance of dust storms. Notably, dust removal event is not always proportional to background wind speed, meaning that dust removal event is stronger when the background wind speed is higher. This implies that the mechanisms of dust accumulation and removal are complex and cannot be described using a single meteorological indicator. As the first lander to arrive at Mars during the dust storm season, InSight took several actions during the design phase to avoid the risk of dust storms, and the actions can be summarized in two main areas: assessing the impact of dust storms on the performance of EDL system and assessing the impact of dust storms on solar arrays. Four engineering atmospheric models for EDL performance assessment were developed during a preliminary research, which would be of great reference for subsequent engineering designs. The InSight team used the observations from the Martian orbit and surface, and rigorous monitoring of dust storms in the landing zone was carried out in the weeks prior to InSight’s landing. The response of InSight to dust storms provides valuable lessons for our upcoming Mars sample return mission. Prospective scientific guidance is the key to ensuring the successful implementation of engineering tasks. An analysis of the preliminary scenario design for a Mars sample return mission indicates that if the rover reached Mars around September 2029, it is highly likely to coincide with the outbreak of a Martian dust storm. It is recommended that the rover be launched as early as possible in 2028 to avoid the risk of lander landing or rising in a dust storm environment. Nevertheless, theoretical guidance requires accurate measurements of meteorological indicators in the vicinity of the landing zone and further effective integration of global and mesoscale climate models are needed to weigh the meteorological indicators for more accurate assessment and prediction of dust storms.
作者
王誉棋
魏勇
范开
何飞
戎昭金
周旭
谭宁
Yuqi Wang;Yong Wei;Kai Fan;Fei He;Zhaojin Rong;Xu Zhou;Ning Tan(Key Laboratory of Earth and Planetary Physics,Institute of Geology and Geophysics,Chinese Academy of Sciences,Bejing 100029,China;College of Earth and Planetary Science,University of Chinese Academy of Sciences,Beijing 100049,China;Beijing National Observatory of Space Environment,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China;Key Laboratory of Cenozoic Geology and Environment,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China)
出处
《科学通报》
EI
CAS
CSCD
北大核心
2023年第4期368-379,共12页
Chinese Science Bulletin
基金
中国科学院A类战略性先导科技专项(XDA17010201)
中国科学院重点部署项目(ZDBS-SSW-TLC00103)
中国科学院地质与地球物理研究所重点部署项目(IGGCAS-201904,IGGCAS-202102)
中国科学院青年创新促进会(Y2021027)资助
国家自然科学基金(41922031)。
