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
Ashitey Trebi-Ollennu the Caltech, earned in 2007. He joined the NASA Jet Propulsion Laboratory in 1999 and rose through the ranks to become the leader of the team that designed the Mars Rover robot that landed on the red planet. Over the years, his responsibilities have involved flight projects, flight projects review boards, mission formulation, technology tasks, technical writing and proposals. He also served as a reviewer for NASA Science Mission Directorate technology proposals and NASA Office of Education proposals. Other engagements at NASA are 2003 - Mars Exploration Rover, 2007 - Phoenix Mars Lander and Mars Science Laboratory which is scheduled