octagonal structure. Power was supplied by 17,472 photovoltaic cells, covering an area of on the four solar panels. These could provide 800 watts of power near Earth, and 449 watts while at Mars. The maximum power requirement was 380 watts, once Mars was reached. A 1200 watt-hour, rechargeable, silver-zinc battery was used to provide backup power. Thermal control was achieved through the use of adjustable louvers on the sides of the main compartment. Three telemetry channels were available for telecommunications. Channel A carried engineering data at 8⅓ or 33⅓ bit/s, channel B carried scientific data at 66⅔ or 270 bit/s and channel C carried science data at 16,200 bit/s. Communications were accomplished through the high- and low-gain antennas, via dual S-band traveling wave tube amplifiers, operating at 10 or 20 watts, for transmission. The design also included a single receiver. An analog tape recorder, with a capacity of 195 million bits, could store television images for subsequent transmission. Other science data was stored on a digital recorder. The command system, consisting of a central computer and sequencer (CC&S), was designed to actuate specific events at precise times. The CC&S was programmed with both a standard mission and a conservative backup mission before launch, but could be commanded and reprogrammed in flight. It could perform 53 direct commands, 5 control commands, and 4 quantitative commands. Instrumentation: IR Spectrometer Two-Channel IR Radiometer Mars Surface Temperature UV Spectrometer S-Band Occultation Thermal Control Flux Monitor (Conical Radiometer) Mars TV Camera Celestial Mechanics General Relativity See also List of missions to Mars Space exploration Unmanned space missions Heat Flow and Physical Properties Package (Included an infrared radiometer for the martian surface) References External links Mariner Mars 1969 Launches - Press Kit Tracking and data system support for the Mariner Mars 1969 mission. Volume 1 - Planning phase through midcourse maneuver Tracking and data system support for the Mariner Mars 1969 mission. Volume 2: Midcourse maneuver through end of nominal mission Tracking and data system support for the Mariner Mars 1969 mission. Volume 3: Extended operations mission The Mariner 6 and 7 flight paths and their determination from tracking data Two over Mars - Mariner 6 and Mariner 7, February - August 1969 Mariner 6 Mission Profile by NASA's Solar System Exploration Mariner 7 Mission Profile by NASA's Solar System Exploration Mariner 6 and 7 Data Set Information (highly technical) Mariner 6 and 7 Data Viewer