Mars 3 was the first spacecraft to make a soft landing on Mars, in December 1971.
The Soviet Union launched Mars 3 on May 28, 1971, together with its sister spacecraft Mars 2. Mars 3 reached Mars in December and released its lander on December 2, 1971. The lander survived its descent and touched down successfully, making it the first human-made object to achieve a soft landing on the planet.
Its success was brief. Mars 3 began transmitting a partial image, but communications stopped after about 20 seconds. The failure may have been related to severe electrical conditions during a Martian dust storm. The accompanying orbiter continued operating and returned scientific measurements.
Mars 2 arrived shortly beforehand, but its lander crashed during descent, so it was not a soft landing. NASA’s Viking 1 later became the first spacecraft to conduct a long-duration successful landing and surface mission on Mars, beginning operations in 1976.