Editing Mariner 6 and 7 (section)

== Spacecraft and subsystems ==
[[file:Mariner_6_or_7_diagrams.jpg|thumb|Spacecraft and subsystems]]
The Mariner 6 and 7 spacecraft were identical, consisting of an octagonal [[magnesium]] frame base, {{Convert|138.4|cm|abbr=on}} diagonally and {{Convert|45.7|cm|abbr=on}} deep. A conical superstructure mounted on top of the frame held the high-gain {{convert|1|m}} diameter parabolic antenna and four [[Photovoltaic array|solar panels]], each measuring {{Convert|215|cm|abbr=on}} x {{Convert|90|cm|abbr=on}}, were affixed to the top corners of the frame. The tip-to-tip span of the deployed solar panels was {{Convert|5.79|m|abbr=on}}. A low-gain omnidirectional antenna was mounted on a {{Convert|2.23|m|abbr=on|adj=on}} high mast next to the high-gain antenna. Underneath the octagonal frame was a two-axis scan platform which held scientific instruments. Overall science instrument mass was {{Convert|57.6|kg|lb|abbr=on}}. The total height of the spacecraft was {{Convert|3.35|m|abbr=on}}.

The spacecraft was attitude stabilized in three axes, referenced to the Sun and the star [[Canopus]]. It utilized 3 gyros, 2 sets of 6 [[nitrogen]] jets, which were mounted on the ends of the solar panels, a Canopus tracker, and two primary and four secondary [[Sun sensor]]s. Propulsion was provided by a 223-[[newton (unit)|newton]] rocket motor, mounted within the frame, which used the mono-propellant [[hydrazine]]. The nozzle, with 4-jet vane vector control, protruded from one wall of the octagonal structure. Power was supplied by 17,472 [[photovoltaic cell]]s, covering an area of {{Convert|7.7|m2|sp=us}} on the four solar panels. These could provide 800 watts of power near Earth, and 449 watts while near 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 {{frac|8|1|3}} or {{frac|33|1|3}} bit/s, channel B carried scientific data at {{frac|66|2|3}} 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.

=== Scientific Instruments ===
Both spacecraft carried the same set of instruments:<ref>{{Cite web |date=2017-12-20 |title=Mariner 6 - NASA Science |url=https://science.nasa.gov/mission/mariner-6/ |access-date=2025-03-01 |language=en-US}}</ref><ref>{{Cite web |date=2018-01-25 |title=Mariner 7 - NASA Science |url=https://science.nasa.gov/mission/mariner-7/ |access-date=2025-03-01 |language=en-US}}</ref>

* Imaging System (Two TV cameras)
* Infrared Spectrometer
* Ultraviolet Spectrometer
* Infrared Radiometer
* Celestial Mechanics Experiment
* S-Band Occultation Experiment
* Conical Radiometer