Mariner Mars 1964 telemetry and command system
R. P. Mathison · IEEE Spectrum · 1965
The Telemetry and Command System for the Mariner Mars 1964 Mission utilizes an extension of the techniques used for the Mariner Venus 1962 Mission.For both the command and telemetry functions, PCM/PSK/PM modulation-demodulation in combination with pseudorandom sync codes is used.The telemetry system is required to transmit video data from the vicinity of Mars in addition to transmitting other scientific and engineering data during the entire flight.Since the rate at which the video data is gathered exceeds the capability of the telemetry channel, storage and playback are provided by an endless-loop tape recorder.In order to provide the maximum reliability within the constraints of available power and weight, redundant elements have been incorporated in the telemetry modulator and the transmitter.The command system provides for the transmission of and quantitative commands to the spacecraft.