This is the proof test article of the Viking Mars Lander. For exploration of Mars, Viking represented the culmination of a series of exploratory missions that had begun in 1964 with Mariner 4 and continued with Mariner 6 and Mariner 7 flybys in 1969 and a Mariner 9 orbital mission in 1971 and 1972. The Viking mission used two identical spacecraft, each consisting of a lander and an orbiter. Launched on August 20, 1975 from the Kennedy Space Center in Florida, Viking 1 spent nearly a year cruising to Mars, placed an orbiter in operation around the planet, and landed on July, 20 1976 on the Chryse Planitia (Golden Plains). Viking 2 was launched on September 9, 1975 and landed on September 3, 1976. The Viking project's primary mission ended on November 15, 1976, 11 days before Mars's superior conjunction (its passage behind the sun), although the Viking spacecraft continued to operate for six years after first reaching Mars. The last transmission from the planet reached Earth on November 11, 1982.While Viking 1 and 2 were on Mars, this third vehicle was used on Earth to simulate their behavior and to test their responses to radio commands. Earlier, it had been used to demonstrate that the landers could survive the stresses they would encounter during the mission.NASA transferred this artifact to the Museum in 1979.