Washington: Researchers have developed a model called Artemis that accurately simulates rover mobility over various types of soil and terrain.
In May 2009, the Mars rover Spirit cracked through a crusty layer of Martian topsoil, sinking into softer underlying sand. The unexpected sand trap permanently mired the vehicle, despite months of remote manoeuvring by NASA engineers to attempt to free the rover.
MIT`s Karl Iagnemma said that scientists have a pretty good understanding of how soils interact with vehicles that weigh more than 2,000 pounds. But for smaller, lighter vehicles like the Mars rovers, the situation is murkier.
The new model that Iagnemma and researchers from Washington University in St. Louis and the Jet Propulsion Laboratory (JPL) in Pasadena, California, developed works much like a video game: A user plugs in commands to, for example, move the simulated rover forward a certain distance-instructions similar to those that NASA engineers give to rovers on Mars.
The simulation then predicts how the rover will move, based on the underlying soil properties, vehicle characteristics and a terrain`s incline.
The team tested the model against observations in the field, including actual drive paths from previous Mars rovers, and found that the simulations behaved much like actual rovers in various terrains.
The researchers also performed experiments in the lab, rolling a replica of a Mars rover`s wheel over Martian-like sand. The tests established relationships between wheel dynamics and soil properties-information that the team used to further refine the model.
The team coupled Martian soil data with properties of the rover, such as its size and weight, and developed a model to predict the likelihood and extent to which a rover may sink into a given terrain.
The paper is set to appear in the Journal of Field Robotics.