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.
Mars 2
The Mars 2 was an unmanned space probe of the Mars program, a series of unmanned Mars landers and orbiters launched by the Soviet Union May 19, 1971. The Mars 2 and Mars 3 missions consisted of identical spacecraft, each with an orbiter and an attached lander. The orbiter is identical to the Venera 9 bus or orbiter. The type of bus/orbiter is the 4MV. They were launched by a Proton-K heavy launch vehicle with a Blok D upper stage. The lander of Mars 2 became the first man-made object to reach the surface of Mars, although the landing system failed and the lander was lost.On May 19, 1971, the Proton-K heavy launch vehicle launched the probe from Baikonur Cosmodrome. After the first stage separated the second stage was ignited. The third stage engine blasted Mars 2 into parking orbit, then the Blok D upper stage sent Mars 2 on the trans-Mars trajectory.