超低轨道卫星应用离子电推进技术方案

Technical project of ion propulsion for satellites in super low Earth orbit

低地球轨道大气环境对诸如科学探测和对地观测卫星的阻尼作用十分明显,而且阻尼随太阳和地磁活动以及昼夜、季节交替变化范围宽。为了保证卫星轨道精度或飞行状态满足任务要求,需要利用推进系统对卫星受到的阻尼进行实时或间歇式补偿以实现轨道或飞行状态的保持。针对轨道高度220~268 km的无拖曳飞行和轨道维持应用,基于卫星轨道阻尼变化和有效载荷指标要求分析,研究确定了离子电推进技术指标、推力调节方案、系统组成、推力控制方案和在轨应用策略,并对推力调节方案进行了试验验证。结果表明,与无拖曳飞行卫星任务匹配的离子电推进指标为推力调节范围1~20 mN,推力分辨率优于12μN,与对地观测卫星轨道维持任务匹配的指标为推力调节范围1~25 mN,推力分辨率100μN。研究提出的针对超低轨道卫星应用需求的高精度推力连续调节离子电推进技术方案,具有工程任务针对性和参考价值。

The Earth’s outer atmosphere at the low altitude causes a significant drag on the spacecraft such as scientific detection and Earth observationsatellites in super low earth orbit,furthermore the atmospheric drag changes in a wide range along with solar activity,geomagnetic activity,seasonal and diurnal cycle.In order to meet the demands for satellite orbit accuracy or flight conditions,this drag needs to be continuously or intermittently compensated by onboard thrusters.Considering drag free flight and orbit maintenance at an altitude of about 220~268 km,the variety of atmospheric drag and the specifications of the spacecraft payloads were analyzed,and then the researches were carried out on the technical parameters,thrust throttling approaches,system architecture,thrust control project and on-orbit application strategy of ion propulsion.Accordingly thrust throttling tests were executed.The results show that ion propulsion should operates over a thrust range of 1~20 mN with the thrust resolution of 12μN,and over a thrust range of 1~25 mN with the thrust resolution of 100μN for drag free and orbit maintenance mission respectively.The technical project of ion propulsion is valuable for application reference of satellites in super low Earth orbit.