Sojourner was the first successful robotic rover to explore the surface of another planet, specifically Mars. Launched by NASA on December 4, 1996, it was part of the Mars Pathfinder mission. Sojourner's primary mission was to analyze the Martian soil and rocks, providing valuable data about the planet's geology and atmosphere. The rover operated for about 83 Martian days, or sols, far exceeding its planned lifespan of just seven sols. Equipped with cameras and scientific instruments, Sojourner transmitted images and data back to Earth, helping scientists understand the Martian environment and paving the way for future exploration missions.