https://en.wikipedia.org/wiki/Viking_1
WebViking 1 was the first of two spacecraft, along with Viking 2, each consisting of an orbiter and a lander, sent to Mars as part of NASA's Viking program. The lander touched down on Mars on July 20, 1976, the first successful Mars lander in history. Viking 1 operated on Mars for 2307 days (over 6 1 ⁄ 4 years) or 2245 Martian solar days, the longest Mars surface …