Composite Bucketwheel

I mentored the fabrication and testing of the composite bucket wheel for a lunar excavation robot.

A lunar excavation bucket-wheel was designed and fabricated to test wear resistance in environments modeling those which will be encountered while gathering lunar regolith. Explained herein is the process for creating a lunar excavation bucket-wheel, including product fabrication methods and techniques, and recommendations for improvements on test and bucket-wheel designs. Design choices for the wheel’s back plate, individual buckets, stabilizing ring, and leading edges give structural solutions to the challenge of digging in a low-gravity, low-traction environment and blend with material selection to minimize abrasion from regolith, outgassing, and thermal expansion/contraction. The fabricated carbon-fiber/Kevlar bucket-wheel underwent short-term testing in a single-environment sandbox to confirm test rig capabilities for future testing for the identification of an optimal bucket material, leading edge design, leading edge material (sheet metal, Kevlar wrap), and the effect of toughened epoxy on excavation in the harsh lunar environment. Future testing will also include new leading edge designs and testing of the buckets in lunar simulants (JSC-1, GRC-1, and BP-1) and additional excavator-induced oscillatory vibration for improved digging. These results are a foundation for lunar excavator experimentation and support the use of composite materials for lunar robotics.