College - Author 1
College of Engineering
Department - Author 1
Mechanical Engineering Department
Degree Name - Author 1
BS in Mechanical Engineering
College - Author 2
College of Engineering
Department - Author 2
Mechanical Engineering Department
Degree - Author 2
BS in Mechanical Engineering
College - Author 3
College of Engineering
Department - Author 3
Mechanical Engineering Department
Degree - Author 3
BS in Mechanical Engineering
College - Author 4
College of Engineering
Department - Author 4
Mechanical Engineering Department
Degree - Author 4
BS in Mechanical Engineering
Date
6-2021
Primary Advisor
Peter Schuster, College of Engineering, Mechanical Engineering Department
Abstract/Summary
The NASA RASC-AL Moon to Mars competition challenges student teams to develop a lightweight, durable, and hands-off method for extracting water from Martian/lunar subsurface ice layers while mapping soil density profiles. Future interplanetary expeditions are dependent on the availability of clean water and this project aims to accomplish this task. The challenge description enumerates several criteria to be met for successful designs. For further information, the STYX & STONES team conducted research on Cal Poly’s competition project from last year to consider the areas for redesign. As such, the team has utilized the background research from relevant patents and journal articles to consider brainstorming potentially viable solutions. Based on these solutions for each subsystem, the team converged the ideas using a series of decision matrices into a final design direction.
In addition to reviewing the STYX design, several new considerations were made for the scope of this project. Primarily, this year’s team focused on developing a prototype that has the capability of operating in an extraterrestrial environment and thoroughly fulfilling the requirements posed by NASA. To visualize the requirements, the team created a list of customer needs, a House of Quality diagram, and an engineering specifications table. Additionally, the STYX & STONES team discussed the design process it plans to follow including major project milestones. Specifically, the team plans to excel in collecting more than five quarts of water autonomously while successfully identifying the overburden layers – tasks that previous teams have struggled with.
The team’s design direction includes two main components: a masonry drill bit and an auger- heater probe hybrid tool. The masonry drill bit will create a hole in the overburden using the force from a rotary hammer. The heater probe tool will then be moved to align with the hole and be driven into the loosened overburden using the force of a small gear motor. The heater probe will then melt ice using a hot waterjet and deliver water via a peristaltic pump and a two-stage filtration system.
To verify the design, the team completed a multitude of analyses and tests for each subsystem and the prototype as a whole. Through drilling tests, the team found that the rotary hammer and masonry bit can easily cut through all overburden layers while keeping weight on bit (WOB) below 150N. Similarly, the load cells attached to the drill carriage were tested and proven to be accurate at recording WOB data and providing feedback to the controller to monitor WOB. Furthermore, the load cells proved successful at recording accurate WOB data that can be analyzed to determine overburden composition. The pumping system was also tested and was capable of effectively moving water through all filters and delivering fluid to the waterjet. More tests were completed to verify the heater probe tool; these tests included controlling heater temperature, melting ice, expelling water through the waterjet, and removing loose material from the hole.
To verify the design requirements, the team has completed analysis pertaining to each subsystem including the drill, heater probe, frame, and control systems. The team is confident in the drilling
design based on testing and vibrations analysis. In the same manner, the team verified that the 12V peristaltic pump will have enough pressure head rise based on analysis and prototype testing. Using the prototype heater probe as a reference, the team fully characterized the heat transfer parameters of the final design and is confident the auger will be effective considering surrounding debris. Finally, the team tested the water jet design using 120oF water which provided optimistic results that the water jet will significantly expand the melt radius per hole. As a next step, the team will be testing the mechanical and controls systems simultaneously using manufactured parts. The following report details the subsystems and relevant information.
URL: https://digitalcommons.calpoly.edu/mesp/620