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.
Mercury-P
"Mercury-P" would be the first lander on Mercury. A proposed flight scenario for the mission included a flyby of Venus, the insertion of the spacecraft into the orbit around Mercury and the delivery of a lander on its surface. The Institute of Space Research studied the possibility of "recycling" hardware developed for the Phobos-Grunt, Mars-NET, Mars-96, and Solar Sail spacecraft, with proposed upgrades of the hardware. As of 2012, Russian scientists have conducted a preliminary concept study of the project, and compiled a list of the required scientific payload.