1st rover to Mars was successfully sent 20 years ago by NASA
On July 5, 1997, the first successful rover called Sojourner was deployed on Mars' surface via NASA's Pathfinder mission. The images sent by the lander-rover garnered over 200 million hits on the Internet within five days, a web-traffic record at the time, NASA said. Pathfinder was also NASA's third successful Mars lander, after its two Viking landers in 1976.