Viking 1
Viking 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 second spacecraft to soft-land on Mars, and the first soft lander to successfully perform its mission. (The first spacecraft to soft-land on Mars was the Soviet Union's Mars 3 on December 2, 1971, which stopped transmitting after 14.5 seconds.) "Viking 1" held the record for the longest Mars surface mission of days (over 6¼ years) or Martian solar days, until that record was broken by "Opportunity" on May 19, 2010.
List of Mars landers
The following table is a list of successful and unsuccessful Mars landers. As of 2018, 16 lander missions and 5 sub-landers (Rovers and Penetrators) attempted to land on Mars. Of 16 landers, only InSight Mars Lander is currently in operation on Mars. This list excludes rovers, such as Spirit ("Mars Exploration Rover-A"), Opportunity (Mars "Exploration Rover-B") and Curiosity ("Mars Science Laboratory").