Viking 1 made the first fully successful controlled powered landing on Mars on 20 July 1976.
NASA’s Viking 1 consisted of an orbiter and a lander. The lander touched down in Chryse Planitia after separating from the orbiter and using a heat shield, parachute and rocket engines to slow its descent. It returned the first images from the Martian surface and began a long programme of atmospheric, geological and biological experiments.
The Soviet Mars 3 lander achieved a soft landing in 1971, but it transmitted for only about 20 seconds after reaching the surface. Viking 1 is therefore generally credited with the first successful long-lived operation from the Martian surface. Viking 2 landed later in 1976 and also returned extensive data.
The Viking landers searched for signs of microbial activity in Martian soil, but their biological results were not accepted as evidence of life. The mission also measured weather and examined rocks and soil. Viking 1’s success showed that precision entry, descent and landing on Mars was possible with 1970s technology.