Keywords

Regolith Plume Geotechnical Vacuum Moon Mars

Abstract

When landing or launching spacecraft, the impingement of rocket exhaust can cause significant surface erosion on planetary bodies, resulting in high-velocity ejecta, formation of dust and debris clouds, or even cratering. With humans returning to the Moon, and future missions to the surface of Mars, understanding and mitigating rocket plume effects is essential for the protection of personnel and equipment. To better understand the influence of surface properties and environmental conditions on plume induced erosion rates, this study leverages a series of geotechnical measurements and small-scale plume experiments in atmosphere, cold temperatures, and reduced ambient pressures using regolith simulants. This study also examines debris collected from the first Starship test flight to reveal a new launchpad failure mode and predict ejecta velocities on the Moon and Mars. Results show that geotechnical properties and erosion rates can change greatly based on ambient pressure, regolith density, and particle size. Depending on mass flow rate, cohesion has a small, non-linear influence on surface erosion, while ambient temperatures likely have a negligible impact on geotechnical properties and erosion. In addition to affecting geotechnical properties, results also show that a small percentage of absorbed water can cause increased ejecta velocities during pad failure events. While additional research is needed, surface grading and compaction may mitigate some plume effects, but permeable launch and landing pads should be considered. Using results from different ambient conditions, updated erosion rate equations are provided, as well as novel equations for predicting regolith cohesion, shear strength, and internal angle of friction. The results from this study should be included in future mission planning, plume models, and pad designs.

Completion Date

2025

Semester

Spring

Committee Chair

Britt, Daniel

Degree

Doctor of Philosophy (Ph.D.)

College

College of Sciences

Department

Physics

Identifier

DP0029292

Document Type

Dissertation/Thesis

Campus Location

Orlando (Main) Campus

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