Mars Rover Science Mission Assay

Project Overview

As Mars Rover Team Leader, I am currently designing and manufacturing an automated electromechanical soil harvesting and testing subsystem for the 2026 University Rover Challenge (URC). My work focuses on the mechanical and electromechanical design required to reliably collect soil, transfer it through the system, and run assays targeting metabolic activity, proteins, and amino acids. There are two sides of the assembly to prevent cross-contamination between sampling sites.

Soil is collected using an auger-style drill bit with a carbide cutting tip housed inside a close-tolerance stainless-steel tube. Finding a tube with the exact inner diameter and wall thickness I needed was a major design challenge. I was nearly at the point of machining a custom tube before I found the perfect off-the-shelf option. The configuration is designed to handle hard, compacted desert soil. To deal with the extreme torque generated during drilling, I designed a mechanical clamp to rigidly secure the tube in place while the interior drill bit rotates. The clamp uses four bolts for strength and redundancy.

The drill assembly moves vertically along a linear rail system driven by a lead screw actuator powered by a brushless DC motor. A magnetic rotary encoder provides position feedback, and a limit switch allows the system to home itself and track position relative to the defined home position. The rules prohibit the use of soil collected from depths shallower than ten centimeters so position feedback was a must. Once the drill reaches that depth, a servo-actuated sleeve closes the purge opening. After this event drilling continues, ensuring that all soil collected above ten centimeters is discarded.

The soil is dispensed out of the auger tube into a circular container. Water is introduced from above using a peristaltic pump. The water and soil mix with the metabolic activity reactant in a 5 ml test tube.

The right side is a bit more complicated because the soil needs to be split into two paths. On the right side after collection, the carriage aligns itself with the "slide" and opens the door using a servo. The carriage has a sloped floor so as soon as the door opens soil falls. The carriage was designed with zero clearance with the slide, so the bottom of the slide has a chamfer to guide the carriage into place. Rubber bands are used to maintain consistent contact between the carriage and the slide. This beautiful slide was modeled using lofts in SolidWorks. It was one of the most difficult parts of the project, but I have become pretty good at working with lofts. A small motor with an offset weight is mounted to the slide to introduce vibration, which helps prevent soil from getting stuck.

The slide splits the soil into two paths. One path directs material into a removable cache that can be presented to the competition judges. The other path leads to another 5ml test tube. Water is introduced from above mixing the soil with the reactant used to indicate the presence of amino acids and proteins. Since the reactant needs to be 100 degrees celcius I designed a custom heater. The test tube can be easily removed and replaced to meet sanitary requirements.

All the components are mounted on a 300 × 300 mm carbon fiber backplate manufactured using my university's water jet. Before committing to the final layout, I laser cut a prototype of the backplate to validate all the tolerances were correct.

In addition to the mechanical design, I manufactured power distribution enclosures and completed most of the system wiring, including soldered and crimped connections. The system uses XT60, JST, and Dupont connectors. The software runs on a Raspberry Pi, and the script is in Python. I worked closely with the computer engineering team to make sure the software and mechanical design stayed aligned as the system evolved.

The system is actively under development, with ongoing iterations of mechanical design, electrical, and software refinement.

Overall, this project reflects a hands-on, systems-level approach to robotics engineering, where mechanical design, electronics, and software are developed together to create a robust, autonomous science subsystem.