IMPASS (Intelligent Mobility Platform with Active Spoke System) is a high mobility locomotion platform for unmanned systems in unstructured environments. Utilizing rimless wheels with individually actuated spokes, it can follow the contour of uneven surfaces like tracks and step over large obstacles like legged vehicles while retaining the simplicity of wheels. Since it lacks the complexity of legs and has a large effective (wheel) diameter, it can move over extreme terrain, and thus has great potential for search-and-rescue missions, scientific exploration, and anti-terror response applications.