This is the proof test model of the Viking Mars Lander. For exploration of Mars, Viking represented the culmination of a series of exploratory missions that had begun in 1964. 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. Highlighted in this image is the gas chromatograph ? mass spectrometer of the Viking Mars Lander.