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 artificial objects on Mars
The following table is a partial list of artificial objects on the surface of Mars, consisting of spacecraft which were launched from Earth. Most are defunct after having served their purpose, but the "Curiosity" rover and the "InSight" lander are still operational as of 2018. "InSight" is the most recent artificial object to land safely on Mars. The table does not include smaller objects, such as springs, fragments, parachutes and heat shields. As of November 5, 2016, there are about 14 spacecraft missions on the surface of Mars: some of these missions have multiple spacecraft.