Mars Pathfinder Wheel Abrasion Experiment - Ground and flight results

The Mars Pathfinder conducted scientific and technology experiments with a rover and a lander One of the technology experiments carried by the rover was a tribological experiment, called the wheel abrasion experiment, designed to evaluate the abrasiveness of Martian surface material. The experiment was carried on one of the wheels of the rover; Sojourner. Wear was detected by a photodetector through the reduction of reflectance of three types of metal films (Al, Pt, and Ni) on a black anodized substrate attached to the wheel. The Pathfinder mission showed that significant wear occurred on the metal wheel strips, with the most wear on the thinnest aluminum samples, mid the least on the thickest nickel and platinum samples. The depth of dig during a wheel abrasion experiment showed that the surface material is, in some places, very loose, and in other places tightly packed. Laboratory tests using a spare flight wheel demonstrated that the surface simulants used for wear testing adhered to the wheel and that electrostatic charging of the wheel occurred.