The Viking Landers were two robotic spacecraft, Viking 1 and Viking 2, launched by NASA in 1975 to explore the surface of Mars. They were the first successful landers to operate on the Martian surface, conducting experiments to search for signs of life and gather data about the planet's atmosphere and geology. Each lander was equipped with a suite of scientific instruments, including cameras and soil analysis tools. The missions provided valuable information about Mars, including its temperature, wind patterns, and surface composition, significantly advancing our understanding of the planet and paving the way for future exploration.