August 20, 1975
Viking 1 entered into a Mars orbit on June 19, 1976. In order to find a good landing location it began taking pictures of the surface and then made that landing the next day in location Chryse Planitia. It was the second ever landing of a manmade craft on the surface of Mars and the first lander to function over a long period of time.
The lander took weather readings and soil samples using a scoop.