NASA Mars Regolith Excavator

Overview:

Looking for things to do during quarantine, I found a NASA design challenge hosted by GrabCad. The light-weight excavator vehicle under development facilitates the transport of the vehicle through space, but also limits the downward force required by traditional excavation techniques. The challenge consisted of improving the excavator/regolith storage drum for their vehicle to use.

Purpose:

• Practice designing under set parameters and expected outcomes
• Get exposure to the design techniques used at NASA
• Practice CAD and SolidWorks simulation
• Practice product rendering and presentation

Challenges:

• Learn a new software and debug simulation and provide results within deadlines
• Create a simulation that would provide accurate results, but use assumptions that were valid

Outcome:

• Spring loaded shovels are set by ground reaction force when in contact and triggered when the counter force is insufficient (no longer in contact with the ground)
• A drum is made of three modulses that consist of two oppposite facing shovels that trigger at the same time, allowing for some cancelation of forces and decreasing net force on the mechanism
• Spring loaded shovels work in the direction of gravitational force and the rotation of the drum to maximize momentum when coming into contact with the ground
• Aluminum sheet metal assembly with weight saving cut-outs where possible to maximize regolith collection capacity to weight ratio

Things to consider if future design iterations persued:

• Springs loose elasticity over time - because this excavaotor is to be used shortly before human arrival, parts should only family after replacement and maintanance is possible
• Further sand proofing required to prevent jamming and friction