The NASA Jet Propulsion Lab uses neodymium magnets in each of the Mars Exploration Rovers. The magnets are used to collect space dust for examination during the mission.
In the picture at below, three sets of magnets are shown on a picture of the Spirit/Opportunity type of rover. One set of two magnets is mounted on the front of the rover at an angle so that nomagnetic particles will tend to fall off. These magnets are reachable for analysis by various instruments.
A second magnet is mounted on the top of the rover deck in view of the Pancam, next to the color calibration / sundial. This magnet is strong enough to deflect the paths of wind-carried, magnetic dust.
A third set of magnets is carried by the Rock Abrasion Tool (RAT). As the RAT grinds into martian rocks, scientists have the opportunity to study the properties of dust from these outer rock surfaces.
The earlier Pathfinder and later Curiousity rovers use similar magnet arrays for similar reasons. www.aimmagnet.com