A team of researchers from the University of Wisconsin-Madison has uncovered a critical flaw in how lunar and Martian rovers are tested on Earth, which could have led to misleading conclusions about their performance on extraterrestrial missions. The team used powerful simulation tool Chrono to show that test results were overly optimistic due to ignoring how Earth’s gravity affects the terrain itself.
Current testing methods involve creating a lightweight rover prototype, testing it in deserts, and observing its movement across sand. However, this approach overlooked the impact of Earth’s gravity on the desert sand. Researchers found that Earth’s gravity pulls down on sand much more strongly than the gravity on Mars or the moon, making it more rigid and supportive.
In contrast, the moon’s surface is “fluffier” and therefore shifts more easily, reducing the rover’s traction. This means that rovers would experience less mobility on the moon than previously thought. The researchers’ discovery highlights the value of using physics-based simulation to analyze rover mobility on granular soil.
The findings have significant implications for future lunar missions and beyond. By improving terrain testing on Earth, engineers can better prepare rovers for extraterrestrial challenges. The researchers’ work also demonstrates the potential of open-source software like Chrono, which has been used by hundreds of organizations worldwide to solve complex mechanical system problems.
Chrono is free and publicly available, with the UW-Madison team continually innovating and enhancing the software to stay relevant. This research underscores the importance of considering multiple factors when simulating rover mobility on granular soil.
Source: https://www.sciencedaily.com/releases/2025/07/250726234412.htm