Abstract

The Spectrum–Röntgen–Gamma (SRG) space observatory was launched from Baikonur on July 13, 2019, and is currently on a flight trajectory in the vicinity of the collinear Sun–Earth libration point L2. The planned service life of the observatory is 7 years and includes an all-sky survey and in-depth studies of individual objects in the X-ray range 0.3–15 keV. We consider the technical limitations of the mission pertaining to the launch scenario, the spacecraft design and system characteristics, including the data and command transmission, orbital motion and attitude control systems, and the peculiarities of the ground segment used to accomplish these tasks. The flywheel offloading strategy for the attitude control system is analyzed within the mentioned limitations. The goal of this analysis is to determine an optimal balance between the flywheel offloading operations while controlling the attitude of the observatory, the orbital maneuvers to keep it on a given trajectory, propellant consumption, and the requirements from the scientific measurements. The proposed method allows the total propellant consumption to be minimized by coordinated control of the operation of the system of attitude control rocket engines while simultaneously using them to maintain the specified orbital parameters.

中文翻译：

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Spectrum-Röntgen-Gamma天文台的轨道运动和姿态控制

摘要

光谱-伦琴-伽玛（SRG）空间天文台于2019年7月13日从拜科努尔发射升空，目前在共线太阳-地球解放点L2附近的飞行轨道上。天文台的计划使用寿命为7年，包括全天候调查和对X射线范围0.3–15 keV内的单个物体的深入研究。我们考虑了任务的技术局限性，涉及发射场景，航天器设计和系统特性，包括数据和命令传输，轨道运动和姿态控制系统，以及用于完成这些任务的地面部分的特殊性。在上述限制范围内分析了姿态控制系统的飞轮卸载策略。该分析的目的是确定飞轮卸载操作之间的最佳平衡，同时控制天文台的姿态，将其保持在给定的轨迹，推进剂消耗以及科学测量要求的轨道操纵。所提出的方法允许通过姿态控制火箭发动机系统的操作的协调控制来最小化总推进剂消耗，同时使用它们来维持指定的轨道参数。