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.
History of robots
In 2005, Cornell University revealed a robot capable of self-replication; a set of cubes capable of attaching and detaching, the first robot capable of building copies of itself. Launched in 2003, on January 3 and 24, the Mars rovers Spirit and Opportunity landed on the surface of Mars. Both robots drove many times the distance originally expected, and Opportunity was still operating as of mid-2018 although communications were subsequently lost due to a major dust storm.