Mars Rover Locomotion Test for Science Fair

ISEF Category: Engineering Technology: Statics and Dynamics

Subcategory: Ground Vehicle Systems  ·  Difficulty: Intermediate  ·  Setup: School Lab  ·  Time: 1 to 2 Months

The Hook

Mars rovers do not fail because they are slow. They fail when wheels spin, sink, or stall on soft ground. You can test that same problem on Earth with a 3D-printed chassis and a backyard regolith mix. This project turns rover motion into numbers you can measure.

What Is It?

This project compares three ways a rover can move, wheels, tracks, and whegs. Whegs are hybrid legs-wheels. They look like spoked wheels, but they step over bumps better than a normal wheel. Think of them like a walker that also rolls. Each mode handles soft ground and obstacles in a different way.

Your test bed acts like simplified Mars soil. Perlite and sand make a loose surface that shifts under load. That matters because the best rover design is not always the one that moves fastest on a floor. On rough, soft terrain, traction, sinkage, and obstacle climbing matter more than speed alone. You are testing which locomotion mode wastes the least motion and energy when the ground fights back.

Why This Is a Good Topic

This makes a strong science fair topic because you can change one clear variable, the locomotion mode, and measure real outputs like slip, energy per meter, and climb height. It connects to planetary exploration, search-and-rescue robots, and off-road vehicle design. You do not need a professional lab to start, but you do need careful testing and clean measurements. That gives you room to build a project that feels real, not just classroom-level.

Research Questions

• How does locomotion mode affect slip on a loose perlite-sand surface?
• What is the effect of locomotion mode on energy use per meter traveled?
• Does locomotion mode change the maximum obstacle height a rover can climb before stalling?
• To what extent does wheel diameter change traction for the wheeled design on regolith?
• Which locomotion mode keeps the rover moving most consistently across repeated trials?
• How does obstacle shape affect climb success for tracked, wheeled, and whegs designs?

Basic Materials

• 3D-printed rover chassis with interchangeable drive modules
• DC gear motors matched across designs
• Motor controller board
• Battery pack with holder
• Digital multimeter
• Inline power monitor or current sensor module
• Measuring tape or meter stick
• Stopwatch or phone timer
• Digital scale with 0.1 g accuracy
• Large shallow tray or bin for test terrain
• Perlite
• Play sand
• Ruler or calipers for obstacle height
• Smartphone camera for side-view recording
• Tape for marking start and finish lines.

Advanced Materials

• 3D-printed rover chassis with modular suspension mounts
• Multiple matched DC gear motors with encoder feedback
• Microcontroller with logging capability
• Current and voltage sensor module
• Wheel slip markers or high-contrast fiducials
• Load cell or force gauge for drawbar pull tests
• High-speed camera or calibrated phone video app
• Digital inclinometer or tilt stage for terrain control
• Sand table with adjustable compaction layers
• ASTM-style particle size sieves for terrain consistency checks
• 3D-printed obstacle set with controlled geometry
• Battery analyzer or power logging setup.

Software & Tools

• Excel or Google Sheets: Organizes trial data, calculates averages, and graphs slip, energy, and climb height.
• ImageJ: Measures rover position frame by frame from video to estimate slip and obstacle clearance.
• Tracker: Lets you extract motion data from side-view recordings and compare travel distance to wheel rotation.
• Python: Helps you clean data, run statistics, and make plots if you have many trials.
• GeoGebra: Useful for modeling obstacle geometry and estimating the climb angle needed for each rover design.

Experiment Steps

1. Define the performance metrics you will compare, such as slip ratio, energy per meter, and maximum climb height.
2. Choose one rover chassis size and keep mass, motor type, and battery setup as constant as you can across all locomotion modes.
3. Build a terrain test bed that you can refill, level, and reuse so each design faces the same surface conditions.
4. Plan a measurement method for each metric, including how you will record motion, power draw, and climb success.
5. Decide the order of trials and the number of repeats so one lucky run does not decide the result.
6. Set up a data table and analysis plan before testing so you can compare designs with the same calculations every time.

Common Pitfalls

• Letting the sand-perlite mix shift between trials, which changes traction and sinkage without you noticing.
• Measuring slip from a single video angle, which can hide how far the rover really moved.
• Changing motor voltage between locomotion modes, which makes energy comparisons unfair.
• Comparing designs with different masses, which confounds traction with load.
• Stopping obstacle tests as soon as the rover climbs once, which hides how often each mode fails under repeat trials.

What Makes This Competitive

A stronger project does more than say which design won. It explains why the winner won. You can get there by controlling terrain consistency, measuring uncertainty, and separating slip from sinkage and climb ability. If you compare all three modes across several obstacle shapes or soil compaction levels, your results start to look like real engineering data, not a simple demo.

Project Variations

• Test the same three locomotion modes on a steeper slope to see how incline changes traction and stall rate.
• Compare rover performance on dry sand, perlite-sand mix, and packed soil to study how terrain texture changes the ranking.
• Measure how adding suspension or changing chassis mass affects slip and energy use for each drive mode.

Learn More

• NASA Mars rover engineering pages: Search NASA for rover mobility, wheel design, and terrain testing articles.
• NASA Jet Propulsion Laboratory mission pages: Look for rover testing photos, videos, and engineering notes on mobility systems.
• USGS planetary science resources: Search for Mars analog terrain and regolith descriptions.
• MIT OpenCourseWare: Find introductory mechanics and robotics courses for motion, force, and power basics.
• PubMed: Search for review articles on terramechanics, rover mobility, and off-road locomotion.
• IEEE Xplore: Search for papers on wheel-terrain interaction, tracked vehicles, and whegs locomotion.