Viking 1

Viking 1 combined a Mars orbiter and lander to study the planet's surface, atmosphere and potential for life. The orbiter entered Mars orbit on June 19, 1976, using cameras and infrared instruments to survey the surface and help choose a safer landing site. On July 20 the lander touched down in Chryse Planitia, where cameras, weather sensors, a soil sampler and chemistry and biology experiments investigated the local environment. The orbiter operated until 1980 and the lander until 1982.