After some 15 prolific years on the Martian surface, NASA’s Mars Opportunity rover has gone silent. And after an all out effort to re-establish contact, the space agency says it’s given up hopes of ever hearing back from the rover. We talked to the NASA engineers and scientists whose lives have been touched by the Opportunity rover about their experiences and what the craft meant to them. For some researchers, the mission has encompassed their entire career. For others, the spacecraft team w