Mariner 9, launched May 30, 1971, became the first artificial satellite of Mars in November of the same year. Russian probes arrived several weeks later. The probe had to wait for another month, for a planet-wide dust storm to subside before it could take pictures of the surface.
Mariner 9 returned over 7000 pictures of Mars and succeeded in photographing the entire surface. It also sent back close-ups of Phobos and Deimos, the Martian moons.