Viking lander on Mars. Composite image depicting one of the Viking lander spacecraft sitting on the surface of Mars. Two Viking spacecraft were launched to Mars in 1975, each taking just over 300 days to fly there, arriving in June and August 1976. Each Viking had an Orbiter section and a Lander. The landers returned over 4,500 detailed images of the terrain surrounding their landing sites. The landers also performed soil analysis tasks, apparently finding no evidence of biological activity, and made meteorological observations. This image is a digital composite of a photo of the back-up Viking Lander and a photo of Mars terrain taken by the Viking 1 Lander.