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 are a component of many designs for a human mission to the planet Mars. For example, the Austere Human Missions to Mars proposal proposed including two rovers on its unmanned power and logistics cargo lander. Each rover could hold a crew of two in a pressurized environment, with power coming from a Stirling radioisotope generator. Mars One, a Mars colonization plan intended to be funded by a TV show, plans an unpressurized crewed rover capable of traveling 80 km (50 miles). They said a possible supplier was Astrobotic Technology. The Manned Mars Exploration Rover (MMER) won a design award in