Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School

Mechanical Engineering

First Advisor

Todd Letcher


This research project focused on the design and testing of a prototype bucket wheel excavator developed for NASA's Break the Ice Lunar Challenge, which sought innovative ideas for lunar excavation. Several attempts have been made by other universities and private industries to create systems that can successfully excavate simulated frozen regolith, however, few have been successful. The chosen excavation technology employed a bucket wheel concept inspired by large open-pit mining machines, modified to incorporate grinding nubs for pulverizing lunar simulant material. The goals included proving the viability of a bucket wheel excavator for lunar excavation, exploring grinding nubs, conducting durability studies, developing force models, and analyzing long-term system efficiency. A series of tests yielded critical insights. A prototype wheel test demonstrated the effectiveness of grinding nubs and calculated torque requirements for excavation, showing promise for the method. A 15- day Full System Test provided essential insights, confirming the viability of the grinding concept for lunar excavation. Regolith simulant was successfully excavated from the test site and proved that a bucket wheel grinder combination works for this application. Wheel design, grinding system, excavation techniques, drive motor, and size and weight reduction were areas identified for improvement. Proposed design changes included offsetting the wheel for dust reduction, bucket geometry alterations for efficient material retrieval, switching to a linear translating motion for improved trench cutting, and a direct drive motor with ring gearing to eliminate chain-related issues. Despite challenges faced during the full system test, the project's contributions to lunar excavation technology are significant. Lessons learned will guide the development of more reliable and efficient excavation rovers. This research lays a solid foundation for future lunar missions, offering promising prospects for the future of lunar excavation.

Library of Congress Subject Headings

Excavating machinery -- Design and construction.
Excavating machinery -- Evaluation.
Buckets (Excavating machinery)
Lunar soil.
Lunar mining.


South Dakota State University

Available for download on Sunday, December 15, 2024



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