Viking 1

Viking 1 launched on August 20, 1975, and on July 20, 1976 — seven years to the day after Apollo 11 — its lander touched down on Chryse Planitia, becoming the first spacecraft to land successfully on Mars and complete its mission. The first image, of the lander’s own footpad on rust-colored soil, opened a new era of surface exploration.

The lander operated for over six years, analyzing soil with a suite of biology experiments designed to detect life — results that remain debated but were officially inconclusive — while the Viking 1 orbiter mapped the planet from above. Together with its twin Viking 2, the mission produced the definitive portrait of Mars that guided exploration for the next two decades.