标题： 意大利春季贝皮科伦布第二次金星借力期间意外非引力扰动的加速度计测量 显示英文标题

标题： Italian Spring Accelerometer measurements of unexpected Non Gravitational Perturbation during BepiColombo second Venus swing-by

摘要： 意大利弹簧加速度计（ISA）是一款三轴质量-弹簧加速度计，是欧洲航天局（ESA）与日本宇宙航空研究开发机构（JAXA）联合开展的贝皮科伦布太空任务的有效载荷之一。 2018年10月发射时，贝皮科伦布作为一个由三个不同模块组成的堆栈开始了为期七年的巡航，整体被称为水星复合航天器（MCS）。 该航天器将通过其电推进器以及一次、两次和六次引力辅助（分别来自地球、金星和水星）为贝皮科伦布提供所需的Delta V以到达水星。 加速度计安装在水星行星轨道器（MPO）模块上，并且与Ka波段应答机（KaT）跟踪数据一起，主要用于贝皮科伦布无线电科学实验（BC-RSE）。 在第二次金星飞掠期间，预计会受到强烈的潮汐效应和外部扰动的影响，并且这些影响可以通过ISA检测到。 这次飞掠的最近距离约为550公里，IDA敏感元件上的预期重力梯度得到了完美测量。 因此，本文展示了由地外天体直接产生的重力梯度效应的首次检测结果。 然而，在最近距离附近，测量结果显示了一个持续数分钟的虚假加速度事件。 这项工作利用了姿态和轨道控制系统（AOCS）的指令扭矩信息，聚焦并分析了这个ISA加速度信号，并将其归因于MCS航天器上实际作用的净力。 此外，使用一种估算方法，将力的作用点限制在靠近MPO散热器的区域。 显示英文摘要

摘要： The Italian Spring Accelerometer (ISA) is a three axis mass-spring accelerometer, one of the payloads of the BepiColombo joint space mission between the European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA). At launch in October 2018, BepiColombo started its seven-year cruise as a stack of three different modules, overall named Mercury Composite Spacecraft (MCS). The spacecraft will provide BepiColombo the necessary Delta V to reach Mercury with its electric thrusters and along with one, two and six gravity assists, respectively with Earth, Venus and Mercury. The accelerometer is accommodated on the Mercury Planetary Orbiter (MPO) module and, jointly with the Ka-band Transponder (KaT) tracking data, will primarily serve the BepiColombo Radio Science Experiment (BC-RSE). During the second Venus swing-by, strong tidal effect and external perturbations was expected to act on the spacecraft and to become detectable by ISA. The swing-by had a closest approach of about 550 km and the gravity gradient expected on the IDA sensing elements was perfectly measured. Hence, in this paper, the first direct Gravity Gradient effect detection generated by an extraterrestrial body is shown. Nevertheless, around the closest approach, the measurements evidenced a spurious acceleration event lasting for several minutes. This work, exploiting information on the Attitude and Orbit Control System (AOCS) commanded torques, focuses and analyses this ISA acceleration signal, ascribing it to a net force really acting on the MCS spacecraft. Furthermore, using an estimation method, the application point of the force is confined to an area close to the MPO radiator.