Mariner 6

Mariner 6 was one of NASA/JPL's twin Mars flyby spacecraft launched in 1969. A movable instrument platform carried two television cameras, infrared and ultraviolet spectrometers, and thermal instruments; a radio-occultation experiment also examined the atmosphere. Unlike earlier Mariners, its science package concentrated on Mars rather than the intervening space environment. During its July 31 encounter, the spacecraft photographed equatorial terrain and the southern polar region and measured the thin, carbon-dioxide-dominated atmosphere. Infrared observations supported a carbon-dioxide-ice interpretation of the polar cap. Images were recorded for transmission after the brief close passage, and results helped controllers adjust the observing sequence of Mariner 7, which reached Mars a few days later.