Currently, considerable attention is being directed toward active debris removal (ADR) using small, cost-effective satellites. From high altitude to re-entry, ADR missions use thrusters that consume significant amounts of fuel. The volume of the propulsion system in these satellites can be quite large, and it is difficult for a small satellite to accommodate a large-scale propulsion system. Thus, active utilization of atmospheric drag is being considered for small satellites with low capability. However, the principal challenge for small satellites to remove large debris is to deal with the large disturbance torque caused by strong atmospheric drag on the debris. This paper proposes attitude guidance around an equilibrium (balance) point in attitude dynamics acted on by gravity gradient and aerodynamic torques. The desired attitude is set to optimize two conflicting objectives: maximizing the projection area to generate large aerodynamic force and minimizing the disturbance torque. In this paper, we develop an aerodynamic database (ADDB) by rigorously calculating the aerodynamic torque for each altitude and solar array paddle (SAP) rotation based on an aerodynamic characteristic model of free molecular flow. Using the ADDB, the SAP angle and orbit altitude effects on the torque equilibrium attitude (TEA) are clarified. Then, the mean disturbance torque map at each orbit altitude is introduced to obtain the candidate TEA paths. The effectiveness of the proposed paths for debris descent is demonstrated through numerical simulations.

中文翻译：

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使用空气动力学数据库沿扭矩平衡点进行最佳姿态规划，用于使大型空间碎片脱轨

目前，使用小型、经济高效的卫星进行主动碎片清除（ADR）受到了相当多的关注。从高空到重返大气层，ADR 任务使用的推进器会消耗大量燃料。这些卫星中的推进系统体积可能相当大，小卫星很难容纳大型推进系统。因此，对于能力较低的小型卫星，正在考虑积极利用大气阻力。然而，小卫星清除大型碎片的主要挑战是应对碎片上强大的大气阻力造成的大扰动扭矩。本文提出了围绕重力梯度和气动扭矩作用的姿态动态平衡点的姿态引导。设置所需的姿态是为了优化两个相互冲突的目标：最大化投影面积以产生大的气动力和最小化扰动扭矩。在本文中，我们基于自由分子流的气动特性模型，通过严格计算每个高度和太阳能阵列桨（SAP）旋转的气动扭矩，开发了气动数据库（ADDB）。使用 ADDB，澄清了 SAP 角度和轨道高度对扭矩平衡姿态 (TEA) 的影响。然后，引入每个轨道高度处的平均扰动力矩图来获得候选TEA路径。通过数值模拟证明了所提出的碎片下降路径的有效性。