Mars Mariner programme. Technical experts discussing the first digital data transmitted from one of the Mariner space probes. These early interplanetary spacecraft were equipped with analogue cameras, and images were converted to digital data and stored on magnetic tape recorders. The digital data were transmitted back to earth. NASA's Mariner programme launched a series of robotic interplanetary probes from 1962 to 1973, designed to investigate Mars, Venus and Mercury. Mariner 4 performed the first successful flyby of the planet Mars, returning the first pictures of the Martian surface.