For over ten years, NASA engineers have been kicking around the idea of a tumbleweed-inspired Mars rover. This “tumbleweed rover” would be a rugged but lightweight ball, with sensors and other electronics securely suspended inside. It would move about simply at the mercy of the Martian wind, much like its botanical namesake. Until now, the only way of testing such rovers has been to build a prototype, then set it loose here on Earth and watch the fun. That could be about to change, however. Researchers at North Carolina State University have developed a computer model that can test tumbleweed rover designs before they’re ever built.

"You can't just build hundreds of different rover designs to see what works – it's too expensive," said Alexandre Hartl, a Ph.D. student who took part in the research. "This model allows us to determine which designs may be most viable. Then we can move forward to build and test the most promising candidates."

The program takes into account such factors as diameter, elasticity and overall mass. It can also test the designs under different wind conditions, and in different Martian terrains such as rock fields or craters.

"We wanted a way to determine how different tumbleweed rover designs would behave under the various conditions that may be faced on the Martian surface," said Dr. Andre Mazzoleni, co-author of a paper describing the research. "The model that we've developed is important, because it will help NASA make informed decisions about the final design characteristics of any tumbleweed rovers it ultimately sends to Mars."

The research was funded by NASA and the North Carolina Space Grant Consortium. The paper was published in the Journal of Spacecraft and Rockets.