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新型地球观测系统(ECS)公用卫星是为EOS飞行任务(PM、AM和Chemistry飞行任务)的有效载荷公用舱设计的。EOS飞行任务从太阳同步(705km高度)近极地轨道观测地球;三项飞行任务各自携带各不相同的配套仪器,用这些仪器收集有关地球大气、海洋和气候的各种信息。公用卫星必须适应仪器设计(乃至仪器舱)在项目寿命期的可能变化,而不需对卫星本身作重大的设计修改。EOS制导、导航和控制(GNC)系统的主要要求是根据各类星载仪器的要求提出的,每一类仪器对指向精度、姿态测量精度以及在不同时间间隔内的指向稳定度都有不同的要求。有效载荷仪器还产生明显的干扰力矩,大大影响整个航天器的总体性能。GN&C系统的设计考虑了航天器的挠性、安装精度和仪器的测量,同时也考虑了诸如反作用飞轮和天线回转产生的干扰影响。本设计满足了星上仪器的全部要求。姿态控制由反作用飞轮提供保证,反作用飞轮过剩的角动量通过磁力矩器卸载。姿态确定采用天体惯性基准。导航由星上外推地面处理的位置矢量来提供。安全和应急模式完善了正常运行中所采用的精定向和△v机动模式。
The new Earth Observing System (ECS) common satellite is designed for use in the utility payloads of EOS missions (PM, AM and Chemistry missions). The EOS mission observes the Earth from near-polar orbits (at a depth of 705 km) that are synchronized by the sun; each of the three missions carries its own assortment of instruments that collect a variety of information about the Earth’s atmosphere, oceans and climate. Public satellites must adapt to the possible changes in the design of the instrument (and even the equipment compartment) over the life of the project without major design changes to the satellite itself. The main requirements of the EOS guidance, navigation and control (GNC) system are based on the requirements of various types of satellite-borne instruments. Each type of instrument has different pointing accuracy, attitude measurement accuracy and pointing stability at different time intervals Claim. The payload instrument also produces significant disturbing moments that greatly affect the overall performance of the spacecraft. The design of the GN & C system takes into account the flexibility of the spacecraft, the accuracy of the installation and the measurement of the instruments, as well as the effects of disturbances such as reaction flywheels and antenna rotations. This design meets all the requirements of the satellite instrument. Attitude control is provided by the reaction flywheel, and the excess angular momentum of the reaction flywheel is unloaded by the magnetic torque converter. Gesture determination using celestial inertia benchmark. The navigation is provided by extrapolating the terrain’s location vector on the star. Safety and emergency modes improve the fine orientation and Δv maneuvers used in normal operation.