Mars 3 was an unmanned space probe of the Soviet Mars program which spanned the years between 1960 and 1973. Mars 3 was launched May 28, 1971, nine days after its twin spacecraft Mars 2. The probes were identical robotic spacecraft, each consisting of an orbiter and an attached lander. After the Mars 2 lander crashed on the martian surface, Mars 3 lander became the first spacecraft to attain soft landing on Mars. Both probes were launched by Proton-K rockets with Blok D upper stages.