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After more than six years of exploring the Red Planet, the Mars rover Spirit will rove no more. The robotic adventurer is mired in a sand bed, and NASA has officially given up on trying to extricate it. While it will continue to operate as a "stationary research platform" for the time being, there's no denying that the rover's swashbuckling days are over. No longer will Spirit spot an interesting landmark in the distance and gamely trek towards it, with the possibility of a fresh scientific discovery around every corner and under every rock. This photo gallery is a well-deserved eulogy for Spirit, in which we'll survey its travels and achievements. In 2003, NASA's Jet Propulsion Laboratory launched Spirit and its twin rover, Opportunity, on a three-month mission to investigate Martian terrain and atmosphere on opposite sides of the planet. The solar-powered rovers surpassed NASA's wildest dreams, extending their missions by nearly 25 times their anticipated lengths. Since landing on Mars in January 2004, Spirit has snapped more than 127,000 pictures. The robot probed beneath the worn surface of Mars, analyzing the microstructure of rocks and soil with a sophisticated array of instruments: spectrometers, microscopic imagers, and other tools. Spirit has also gathered strong evidence that water once flowed on the Martian surface, which could have created a hospitable environment for microbial life. Spirit and its twin rover (which is still traveling on) will be replaced by more advanced machines that will roll onto the Martian soil in the coming decades. But Spirit will be remembered long after its operating system flickers off for good. Like a robotic Neil Armstrong, the rover has earned its place in the space explorers' hall of heroes.
