Numerous missions are being proposed which involve multiple spacecraft operating in close proximity in harsh charging environments. In such missions, the ability to sense the electrostatic potential on a nearby object is critical to prevent harmful electrostatic discharges or to leverage Coulomb interactions for relative motion control. The electron method is one such technique for touchless potential measurement which works by measuring low-energy secondary or photoelectrons emitted from the target. Previous work has demonstrated the efficacy of the electron method for touchless sensing, but has been limited to consideration of simple shapes and uniformly charged targets. This paper investigates the electron method for touchless sensing for cases in which the target spacecraft has more complex geometry primitives, including boxes, panels, and dishes. Further, the differential charging case, in which the target object is charged to multiple, different potentials, is also considered. A simulation framework is developed to model electric fields and particle trajectories around such spacecraft geometries. Vacuum chamber experiments validate the simulation results. The study shows how the target geometry can focus or defocus the electron flux into streams of electrons emanating from the surface. This provides critical insight into where to place the servicer vehicle to measure these fluxes and determine the target spacecraft potential.

正在提出许多任务，其中涉及在恶劣的充电环境中近距离运行的多个航天器。在此类任务中，感知附近物体静电势的能力对于防止有害静电放电或利用库仑相互作用进行相对运动控制至关重要。电子法是一种用于非接触式电位测量的技术，它通过测量从目标发射的低能二次电子或光电子来工作。以前的工作已经证明了电子方法用于非接触式传感的功效，但仅限于考虑简单的形状和均匀带电的目标。本文研究了用于非接触式传感的电子方法，其中目标航天器具有更复杂的几何基元，包括盒子、面板、和菜肴。此外，还考虑了差动充电情况，其中目标物体被充电到多个不同的电位。开发了一个模拟框架来模拟围绕此类航天器几何形状的电场和粒子轨迹。真空室实验验证了模拟结果。该研究显示了目标几何结构如何将电子通量聚焦或散焦成从表面发出的电子流。这提供了关于将服务车辆放置在何处以测量这些通量并确定目标航天器潜力的关键洞察力。开发了一个模拟框架来模拟围绕此类航天器几何形状的电场和粒子轨迹。真空室实验验证了模拟结果。该研究显示了目标几何结构如何将电子通量聚焦或散焦成从表面发出的电子流。这提供了关于将服务车辆放置在何处以测量这些通量并确定目标航天器潜力的关键洞察力。开发了一个模拟框架来模拟围绕此类航天器几何形状的电场和粒子轨迹。真空室实验验证了模拟结果。该研究显示了目标几何结构如何将电子通量聚焦或散焦成从表面发出的电子流。这提供了关于将服务车辆放置在何处以测量这些通量并确定目标航天器潜力的关键洞察力。