基于激光干涉星间测距原理的下一代月球卫星重力测量计划需求论证

Demonstration of Requirement for Future Lunar Satellite Gravity Exploration Mission Based on Interferometric Laser Intersatellite Ranging Principle

月球卫星重力测量是21世纪国际开展深空探测的发展趋势和追逐热点。月球重力场的精密测量是国际探月计划的重要组成部分,它决定着月球探测器的轨道优化设计和载人登月飞船月面理想着陆点的合适选取。本文首先介绍未来国际GRAIL(Gravity Recovery and Interior Laboratory)月球重力场探测双星计划的总体概述、关键载荷以及科学目标和研究方向。其次,重点阐述月球卫星观测模式可行性论证、月球卫星关键载荷的优化选取、卫星轨道参数的优化设计、仿真模拟研究的先期开展等我国将来月球卫星重力测量计划的实施建议。第一,由于高低/低低卫星跟踪卫星结合多普勒和甚长基线干涉系统观测模式(SST-HL/LL-Doppler-VLBI)对中长波月球重力场的探测精度较高,技术要求相对较低,月球重力场测定速度快、代价低和效益高,可借鉴地球重力卫星GRACE(Gravity Recovery and Climate Experiment)系统的成功经验,对定轨精度的要求较低,而且可有效探测远月面区域的月球重力场信号,因此我国将来首期月球卫星重力测量计划采用SST-HL/LL-Doppler-VLBI观测模式较优。第二,我国应先期开展高精度的月球重力卫星关键载荷(激光干涉星间测距仪、非保守力补偿系统等)和地面Doppler-VLBI系统的研制工作。第三,月球卫星轨道高度(50～100 km)和星间距离(100±50 km)的优化设计是成功实施将来我国月球卫星重力测量计划的重要保证。第四,建议我国将仿真技术应用于月球重力卫星的方案论证、系统设计、部件研制、产品检验、实际应用、故障分析等研制和运行的全过程。本文的研究不仅对我国将来首期月球卫星重力测量计划的成功实施具有重要的参考价值,同时对未来国际太阳系行星重力探测的发展方向具有广泛的指导意义。

The lunar satellite gravity exploration is the international development trend and focus of deep space exploration in the 21st century.The accurate measurement of lunar gravitational field is an important part of international lunar exploration mission,which determines the optimum design of lunar probe orbit and the suitable selection of ideal landing point from manned spacecraft in the lunar surface.Firstly,the future twin-satellite program for the Gravity Recovery and Interior Laboratory（GRAIL） lunar gravitational field exploration is introduced,including general overview,pivotal payloads,and scientific objectives and research direction.Secondly,the executive suggestions including the feasible demonstration of lunar satellite tracking modes,the optimal selection of key payloads from lunar satellite,the optimized design of lunar satellite orbital parameters,and the previous implementation of simulation research are expatiated.（1） Because the measurement accuracy of the medium-long-wavelength lunar gravitational field is high based on the Satellite-to-Satellite High-Low/Low-Low Tracking associated with the Doppler and Very Long Baseline Interferometry mode （SST-HL/LL-Doppler-VLBI）,its technical requirement is low,the lunar gravitational field can be quickly,low-costly and high-efficiently determined,the successful experiences of integrated system from the dedicated Earth＇s gravity satellite-the Gravity Recovery and Climate Experiment（GRACE） are used for reference,the requirement to orbital accuracy is low,and the farside signals of lunar gravitational field can be obtained effectively,it is optimal to use the SST-HL/LL-Doppler-VLBI mode in the future first lunar satellite gravitational exploration mission in China.（2） The high-accuracy key payloads including the interferometric laser ranging system,compensating system of nonconservative force from lunar gravity satellite and Earth＇s Doppler-VLBI system should be developed in advance.（3） The optimal design of orbit altitude（50~100 km） and intersatellite range（100±50 km） for lunar gravity satellite is an important guarantee on the successful execution of future lunar satellite gravity exploration mission in China.（4） The emulational technique should be used in the whole process of development and operation of the lunar gravity satellite including concept demonstration,system design,component development, product test,practical application and fault analysis.This study has not only the important reference value to the successful execution of future lunar satellite gravity exploration in China,but also the comprehensive guiding significance to the development direction of international future planetary gravity exploration in the solar system.