Electrospray Thruster Plume Impingement on CubeSat Solar Arrays: A Particle-Tracking Study

TL;DR

The paper addresses electrospray plume impingement on CubeSat solar arrays by developing a validated particle-tracking framework that models a forward-peaked cosine-power plume ($k=1.8$, $\theta_{max}=46^\circ$) and simulates nine thruster configurations across 1U, 3U, and 6U CubeSats with body-mounted and deployable arrays. It provides quantitative metrics for thrust efficiency and surface contamination, showing that deployable arrays reduce contamination by up to $\sim77\%$, side-mounted thrusters nearly eliminate impingement, and corner-mounted configurations offer intermediate performance, all with statistical uncertainty $<0.15\%$ across trials. The work yields actionable design guidelines for mission planners balancing power, propellant, and mass budgets, and demonstrates validation against experimental divergence data with errors below 7\%. These results establish a practical framework for integrating electrospray propulsion into small satellites while controlling surface contamination and efficiency losses.

Abstract

Electrospray thrusters are emerging as a leading propulsion technology for CubeSats, offering high specific impulse ($I_{sp} > 1000$ s) and low power requirements. However, the divergent ion plumes can impinge on spacecraft surfaces, particularly body-mounted solar arrays, causing contamination and thrust efficiency losses. This study presents a validated particle-tracking simulation to quantify the effects of thruster placement on thrust efficiency and surface contamination for 1U, 3U, and 6U CubeSats. The plume model employs a cosine power distribution ($k=1.8$) with half-angle $46^\circ$, validated against experimental data with errors below 7%. Results show that thrust efficiency ranges from 53.6% for rear-mounted thrusters on 3U body-mounted configurations to 100% for side-mounted configurations with deployable arrays. CubeSat size significantly affects impingement: 3U platforms experience 46.4% contamination with rear-mounted thrusters compared to 16.6% for 1U. Deployable solar arrays reduce contamination by 77% compared to body-mounted arrays, while side-mounted thrusters eliminate impingement entirely at the cost of only 1.6% efficiency loss. Corner-mounted configurations at $30^\circ$ cant provide intermediate performance with 88.9% efficiency and 11.1% contamination. These quantitative design guidelines enable mission planners to optimize thruster integration based on power budget and propellant mass constraints, with statistical uncertainty below 0.15% across all configurations.

Figures (3)

• Figure 1: 1U CubeSat with body-mounted arrays (blue/red), rear thruster (black), and thrust vector (red arrow).
• Figure 2: Plume validation showing divergence angle CDF (left) and velocity histogram (right) matching target parameters.
• Figure 3: Particle trajectories for 3U body-mounted rear configuration showing escaped (blue) and impinged (red) particles.