Master's Thesis Defense

Luca Scifoni

(Advisor: Prof. Romero-Calvo)

"Trade Space Analysis and Optimization of Rigid Electrodynamic Dust Shields for Lunar Dust Mitigation"

Monday, December 2 

11:30 a.m.

Engineering Science & Mechanics (ESM) Building 108

Abstract

Humanity has not set foot on the Moon since 1972. With the Artemis program aiming for long-term settlement, old challenges recognized during the Apollo missions resurface. The harsh environment, particularly the adhesive, abrasive, and electrostatically charged nature of lunar dust, poses significant obstacles and threats. Developing effective dust mitigation technologies is essential for ensuring crew safety and maintaining the functionality and longevity of surface equipment.
The Electrodynamic Dust Shield (EDS) is considered one of the most promising solutions, using high-voltage AC signals applied to electrode arrays to generate electrodynamic waves that repel dust. Despite extensive research on its efficacy, further optimization of operational parameters and an understanding of long-term device degradation are necessary for its deployment in lunar missions. This study focuses on EDS devices realized using nanocomposite chemically modified reduced graphene oxide (CMrGO) electrodes on high-density polyethylene (HDPE) substrates, with innovative dielectric coatings of polystyrene and trichloro perfluorooctyl silane (TPFS).

Experiments are conducted under very-high vacuum conditions in a setup designed to replicate key aspects of the lunar environment, including the photoionization of dust grains by solar radiation, simulated using an ultraviolet (UV) lamp, and dynamic dust deposition, achieved through a dust-falling device. This system allows for more realistic testing conditions by simulating natural dusting mechanisms and introduces an innovative approach in the literature.

A statistical analysis evaluates how the voltage and frequency of AC signal and the coating material impact EDS performance. Data is obtained through image analysis and is compared with a numerical model predicting the effect of frequency. An assessment of device degradation over prolonged operation and of the size of residual dust, analyzed via optical microscopy, is also included.
The results reveal clear differences in the response of distinct devices to varying voltages, particularly when different coatings are applied. The coating type strongly influences the voltage range at which devices can operate without micro-discharges, with the TPFS coating offering the best balance. The signal frequency has a noticeable but less significant impact on performance, and despite some data scatter, the experimental findings closely align with the predictions from the numerical model, highlighting the existence of an optimal frequency value.

Committee
•    Dr. Álvaro Romero-Calvo – School of Aerospace Engineering (advisor)
•    Dr. E. Glenn Lightsey – School of Aerospace Engineering
•    Dr. Thomas Orlando – School of Chemistry and Biochemistry