Infographic of Every Mission to Mars
This infographic is of every mission to Mars ever. As you can see, probes to Mars often fail; as of July 2012, the success rate was 47%. It was the Soviet Union that first sent unmanned space probes to Mars; many failed. In 1971 the lander Mars 2 became the first object from Earth to reach the surface of Mars (unfortunately it crashed). The Mars 3 lander did land on Dec 2, 1971, and transmitted data before falling silent. The Viking 1 and 2 landers not only reached Mars’ surface in 1976, but also gathered soil samples for analysis and took many photos. In 1997 the Mars Pathfinder released Sojoiner onto the Martian surface, which it explored for nearly three months before contact was lost. A high res version is in the link below.