This paper presents an initial feasibility study on the use of ionic-liquid ion sources for electrostatic actuation on atmosphere-less planetary bodies. The natural surface charging of atmosphere-less planetary bodies has been studied as the cause of the transport of regolith across the surface and for electrostatic levitation of a spacecraft in proximity to small asteroids. The low magnitude of the natural surface electric field (order $10\hspace{0.17em}\hspace{0.17em}\mathrm{V}/\mathrm{m}$) severely limits the capability of a vehicle to leverage electrostatic levitation as its maneuvering strategy, particularly on large planetary bodies, such as the Moon. Ionic-liquid ion sources are considered as an actuator for charging of both the vehicle as well as the local surface of the planetary body. By irradiating the surface with ions, the surface electric field can be increased far beyond its natural value and could enable electrostatic levitation on planetary bodies as large as the Moon with current technology. A low-fidelity analytical model of the charging process is developed to estimate requirements on the local surface charge density and limitations on the levitation height and translational speed of the vehicle. Experiments are conducted in a laboratory environment to demonstrate the feasibility of using ionic-liquid ion sources for combined vehicle and surface charging by creating a 1 mN electrostatic force through charge transport while requiring only 0.2 mW of input power. These experiments are in reasonable agreement with the low-fidelity model that describes the fundamental physics of this concept.

本文介绍了使用离子液体离子源在无大气层行星体上进行静电致动的初步可行性研究。已经研究了无大气层行星体的自然表面带电，这是造成巨石在整个表面上运输的原因，也是航天器在小型小行星附近静电悬浮的原因。自然表面电场的低幅值（阶$10\hspace{0.17em}\hspace{0.17em}\mathrm{伏特}/\mathrm{米}$）严重限制了车辆利用静电悬浮作为其机动策略的能力，尤其是在大型行星体（例如月球）上。离子液体离子源被认为是用于对车辆以及行星体的局部表面进行充电的致动器。通过用离子辐照表面，表面电场可以增加到远远超过其自然值，并且可以使用当前技术在像月球一样大的行星体上实现静电悬浮。开发了充电过程的低保真分析模型，以估计对局部表面电荷密度的要求以及对车辆的悬浮高度和平移速度的限制。在实验室环境中进行的实验表明，通过电荷传输产生1 mN的静电力，而仅需要0.2 mW的输入功率，就可以将离子液体离子源用于车辆和表面的联合充电。这些实验与描述该概念基本物理原理的低保真度模型合理地吻合。