Curiosity (rover) conditions favorable for microbial life, including investigation of the role of water; and planetary habitability studies in preparation for human exploration. In December 2012, "Curiosity" two-year mission was extended indefinitely. On August 5, 2017, NASA celebrated the fifth anniversary of the "Curiosity" rover landing and related exploratory accomplishments on the planet Mars. The rover is still operational, and as of , "Curiosity" has been on Mars for sols ( total days) since landing on August 6, 2012. "(See current status.)" "Curiosity" design will serve as the basis for the planned Mars 2020 rover. As established by the Mars Exploration Program,
Mars Exploration Rover "Opportunity" marked six years on Mars, respectively. On January 26, NASA announced that "Spirit" will be used as a stationary research platform after several months of unsuccessful attempts to free the rover from soft sand. NASA announced on March 24, 2010, that "Opportunity", which has an estimated remaining drive distance of 12 km to Endeavour Crater, has traveled over 20 km since the start of its mission. Each rover was designed with a mission driving distance goal of just 600 meters. One week later, they announced that "Spirit" may have gone into hibernation for the Martian winter and might not