Viking 1 was the first of two spacecraft sent to Mars as part of NASA's Viking program, and holds the record for the longest Mars surface mission of 6 years and 116 days (from landing until surface mission termination, Earth time).
Viking 1 was the first of two spacecraft sent to Mars as part of NASA's Viking program. The first spacecraft to successfully land on Mars, it holds the record for the longest Mars surface mission of 6 years and 116 days (from landing until surface mission termination, Earth time).