35 years ago today, Viking 1 departed to Mars. Eleven months later, it showed the sand, rocks and sky of the legendary Red Planet for the first time:
After that, it started a series of experiments to analyze the martian soil and search for traces of life.
The Viking I and II spacecrafts were just a small part of the Voyager Mars Program (which was unrelated to the Voyager spacecraft). The Voyager Mars Program was designed to follow Apollo. It would have culminated on the first human Mars landing in the 1980s. Imagine that: Humans on Mars in the 80s. Astronauts with shoulder pads, breathing oxygen, nitrogen and hairspray, listening to mix tapes of Duran Duran and Donna Summer.