Mars rover to regain contact. Mars 2, Mars 3 were physically tethered probes; "Sojourner" was dependent on the Mars Pathfinder base station for communication with Earth; MER-A & B and "Curiosity" were on their own. Of these "Curiosity" is still active, and "Spirit", "Opportunity" and "Sojourner" completed their missions before losing contact. Seven rovers have been dispatched to Mars: "Examples Landed instrumentation" (Rovers) Mars rovers in development include: One experimental design, not proposed for any actual mission, is: NASA distinguishes between "mission" objectives and "science" objectives. Mission objectives are related to progress in space technology and development processes. Science objectives are met
Crewed Mars rover design, which featured a six-wheel design, enclosed cab, and a mobile laboratory concept. The rover concept is a Non-NASA design, but did debut at the Kennedy Space Center's "Summer of Mars" and is back dropped by agencies goal of getting humans to Mars by the early 2030s. "Car and Driver" magazine reported on this event, and dubbed it a 'Mars Car' noting the designers and various specifications of the vehicle such as its size. An example of an in-house NASA design for rover, is the wheeled version of the Space Exploration Vehicle, which can has a version for outer space.