The Viking 2 mission was part of the American Viking program to Mars, and consisted of an orbiter and a lander essentially identical to that of the Viking 1 mission. The Viking 2 lander operated on the surface for 1316 days, or 1281 sols, and was turned off on April 11, 1980 when its batteries failed. The orbiter worked until July 25, 1978, returning almost 16,000 images in 706 orbits around Mars.
Heliocentric N/AViking 1 was the first of two spacecraft (along with Viking 2) sent to Mars as part of NASA's Viking program. On July 20, 1976, it became the first spacecraft to land successfully on Mars and perform its mission. Viking 1 held the record for the longest Mars surface mission of 2307 days or 2245 sols until that record was broken by Opportunity on May 19, 2010.
Heliocentric N/A