基于航天器飞越探测的小行星轨道、质量与密度确定研究

The project is mainly centered on the determination of asteroid mass, bulk density as well as its orbital characteristics as during a fly-by of the asteroid by a spacecraft. First, based on the tracking date of Chang'E-2's fly-by of Toutatis, and with the application of various data collected by ground stations and onboard solar monitoring cameras, the asteroid's orbit and mass are determined. Based on that, further study is carried out on the construction of measurement equation, combined orbit determination method of the asteroid and the spacecraft, as well as a 3-dimensional reconstruction of the asteroid and its volume measurement method with the use of imaging data. Finally, through the above researches, a measuring method of asteroid orbit, mass and its density based on a fly-by exploration is established. In addition, the study can also provide theoretical support to the forthcoming deep space exploration in terms flight planning and objective setting.

本项目主要开展基于航天器飞越的小行星轨道、质量和体密度测定的相关研究。项目首先针对CE-2飞越Toutatis小行星的探测任务，利用地面和航天器采集的各类测量数据，确定Toutatis的轨道和质量。然后在此研究基础上，进一步开展基于航天器对小行星成像观测的相对测量建模、小行星/航天器联合定轨方法，以及基于成像数据的小行星三维形状重构和体积测定方法等研究，最终建立基于航天器飞越探测的小行星轨道、质量和密度测定的方法。项目研究成果还可对今后我国深空探测任务的科学目标和飞行计划的制定提供一些理论支持。

项目开展了航天器/小行星联合定轨研究，建立了基于图像观测的相对观测方程、小行星轨道和质量确定方法，并基于CE-2飞越Toutatis 小行星的各类测量数据，进行了联合定轨计算，结果表明通过联合定轨可以显著提高航天器和小行星之间的相对位置精度，此方法可应用于今后行星探测任务中，通过成像观测提高探测器在捕获阶段的导航精度；对小行星质量确定分析表明，要有效获取天体质量，需要进一步提高当前对航天器的无线电跟踪精度，并避免飞跃前后数周时间内的姿态和轨道调整。项目还开展基于成像数据的小行星三维形状重构和体积测定方法等研究。项目研究成果还可对今后我国深空探测任务的科学目标和飞行计划的制定提供一些理论支持。