标题： 关于天琴的有效载荷架构和指向控制策略 显示英文标题

标题： On payload architecture and pointing control strategies for TianQin

摘要： 天琴是一项拟议中的空间引力波探测任务，其特点是采用三角形星座结构，位于圆形高地球轨道上。该任务包括三颗无拖曳控制的卫星，以及在远距离卫星上具有严格光束指向要求的长距离激光干涉测量。对于有效载荷架构和指向控制策略，每颗卫星配备两个测试质量，每个激光臂一个，并旋转整个光学机械组件（每个组件包括一个望远镜、一个光学平台、一个惯性传感器等），以补偿星座呼吸角，这是天琴的一个重要选项。在本文中，我们从科学模式下测试质量和卫星控制的角度，考虑扰动轨道和轨道重力梯度，研究其适用性。首先，基于轨道-姿态耦合关系，估计了测试质量悬挂控制所需的静电力和力矩，发现它们对加速度噪声预算足够小。进一步优化建议将两个测试质量的质心与卫星的质心共线且等距，并沿敏感轴向前略微偏移组件枢轴的位置。其次，计算了卫星所需的控制力和力矩，并在卫星上具有平顶太阳罩且太阳角度变化的约束条件下找到了推力分配方案。研究结果表明，可以采用两个测试质量和望远镜指向方案用于天琴。 显示英文摘要

摘要： TianQin is a proposed mission for space-based gravitational-wave detection that features a triangular constellation in circular high Earth orbits. The mission entails three drag-free controlled satellites and long-range laser interferometry with stringent beam pointing requirements at remote satellites. For the payload architecture and pointing control strategies, having two test masses per satellite, one for each laser arm, and rotating entire opto-mechanical assemblies (each consisting of a telescope, an optical bench, an inertial sensor, etc.) for constellation breathing angle compensation represent an important option for TianQin. In this paper, we examine its applicability from the perspectives of test mass and satellite control in the science mode, taking into account of perturbed orbits and orbital gravity gradients. First, based on the orbit-attitude coupling relationship, the required electrostatic forces and torques for the test mass suspension control are estimated and found to be sufficiently small for the acceleration noise budget. Further optimization favors configuring the centers of masses of the two test masses collinear and equidistant with the center of mass of the satellite, and slightly offsetting the assembly pivots from the electrode housing centers forward along the sensitive axes. Second, the required control forces and torques on the satellites are calculated, and thrust allocation solutions are found under the constraint of having a flat-top sunshield on the satellite with varying solar angles. The findings give a green light to adopting the two test masses and telescope pointing scheme for TianQin.