Sandstalker is a manned, unpressurized vehicle that is designed for first exploration of Mars. It is a design study to outline another point of view considering mars exploration vehicles. It is designed to transport two astronauts and special scientific equipment to destinations up to a radius of 25 miles. It is a foldable and lightweight construction, so the transport in an average NASA transportation box is possible. The ability to move easily and safely across the martian surface results from the new construction of the wheels, the wheel arrangement and the wheel suspension. The spider-like structure of the vehicle offers an extreme maneuverability and supports the concept of an all-terrain vehicle able to surcome many different surface obstacles. The reduction of weight, improvement of the wheels and the seats in particular represents the main tasks of M.A.T.V.