Uranus is a sophisticated vehicle for autonomous mobile robot research. As an omni-directional mobile base, it makes possible experiments in perception, real-world modeling, navigation, planning and high-level control. It is self-propelled and can support a wide variety of sensor and manipulator packages. True autonomy is possible as electrical and computing power are carried on-board. The most unique feature of Uranus is its four wheels. Developed by a Swedish company, MECANUM, for omni-directional movement of factory floor pallets and wheel chairs, we have adapted them for use in mobile robots. With respect to the wheels' Swedish origin, we pronounce Uranus: Oo-ron'-00s.