Plan for compensation of self-gravity on ST-7/DRS
Plan for compensation of self-gravity on ST-7/DRS
复制标题
DOI：
10.1088/0264-9381/22/10/007
复制
发表时间：
2005-04
影响因子：
3.5
通讯作者：
Jordan P. Evans
中科院分区：
文献类型：
--
作者：
Jordan P. Evans
空间技术7号（ST-7）有效载荷，在激光干涉仪空间天线（LISA）探路者（LPF）任务中飞行，将演示在1 mHz至30 mHz频率范围内，在加速度干扰低于3 × 10 - 14 m s - 2 Hz - 1/2的情况下对测试质量的无拖曳控制。为抵消静态质量分布不平衡所需要的静电力引入的低频加速度噪声预计将成为加速度噪声预算的重要贡献者。由于这个原因，自重力（由于质量不平衡）通过增加修整质量来最小化，使两个测试质量之间由于自重力在任何轴上的总加速度差低于5 × 10−10 m s−2，并且由于自重力在任何轴上的直流加速度梯度低于4 × 10−8 m s−2 m−1。制定了发展补偿群众分配和安置的方案。补偿自重力对两个测试质量的影响分两步进行。一个标称补偿质量很早就被定义和纳入，并且位于非常接近测试质量的位置。最后的自重力调整发生在航天器集成之后，在外部添加小质量的测试质量真空外壳。该计划确定了硬件成熟度的三个初步点，在这些点上可以进行对建成配置的调整：(1)传感器真空外壳的构建期间，(2)集成ST-7交付到欧洲之前，以及(3)集成LPF系统的环境测试之前。在确定最终修整机会和安装位置时，考虑了自重力对实际质量分布中的知识误差的敏感性。
The Space Technology 7 (ST-7) payload, flying on the Laser Interferometer Space Antenna (LISA) Pathfinder (LPF) mission, will demonstrate drag-free control of a test mass with acceleration disturbances below 3 × 10−14 m s−2 Hz−1/2 over a frequency range of 1 mHz to 30 mHz. Low-frequency acceleration noise introduced by the electrostatic force needed to counter static mass distribution imbalance is expected to be a significant contributor to the acceleration noise budget. For this reason, the self-gravity (due to mass imbalance) is minimized by adding trim mass to bring the total differential acceleration between the two test masses due to self-gravity below 5 × 10−10 m s−2 in any axis and the dc acceleration gradient due to self-gravity below 4 × 10−8 m s−2 m−1 in any axis of either test mass. A plan has been established to develop the distribution and placement of the compensation masses. Compensation for the self-gravity effects on the two test masses is handled in a two-step process. A nominal compensation mass is defined and incorporated early and is located very near the test masses. The final trimming for self-gravity occurs after the integration on the spacecraft with small mass added externally to the test-mass vacuum enclosures. The plan identifies three preliminary points in the hardware maturity where the trimming to the as-built configuration can take place: (1) during build-up of the sensor vacuum enclosure, (2) prior to delivery of the integrated ST-7 to Europe and (3) prior to environmental testing of the integrated LPF system. The sensitivity of the self-gravity to knowledge errors in the actual mass distribution is taken into account in the determination of final trimming opportunities and mounting locations.