Editing Pioneer 10 (section)

====Power and communications====
[[File:NASM-NASM2016-00091.jpg|thumb|SNAP-19 RTGs mounted on an extension boom of ''Pioneer 10'' replica]]

''Pioneer 10'' uses four [[SNAP-19]] [[radioisotope thermoelectric generator]]s (RTGs). They are positioned on two three-rod trusses, each {{convert|3|m|ft|sp=us}} in length and 120 degrees apart. This was expected to be a safe distance from the sensitive scientific experiments carried on board. Combined, the RTGs provided 155&nbsp;W at launch, and decayed to 140&nbsp;W in transit to Jupiter. The spacecraft required 100&nbsp;W to power all systems.<ref name="NASA_sp349_396"/>{{rp|44–45}} The generators are powered by the radioisotope fuel [[plutonium-238]], which is housed in a multi-layer capsule protected by a graphite heat shield.<ref name=skrabek_mcgrew1987/>

The pre-launch requirement for the SNAP-19 was to provide power for two years in space; this was greatly exceeded during the mission.<ref name=bennett_skrabek1996/> The plutonium-238 has a [[half-life]] of 87.74 years, so that after 29 years the radiation being generated by the RTGs was at 80% of its intensity at launch. However, steady deterioration of the [[thermocouple]] junctions led to a more rapid decay in electrical power generation, and by 2001 the total power output was 65&nbsp;W. As a result, later in the mission only selected instruments could be operated at any one time.<ref name=prd65_8/>

The space probe includes a redundant system of [[transceiver]]s, one attached to the narrow-beam, [[high-gain antenna]], the other to an omni-antenna and medium-gain antenna. The parabolic dish for the high-gain antenna is {{convert|2.74|m|ft|sp=us}} in diameter and made from an aluminum honeycomb sandwich material. The spacecraft was spun about an axis that is parallel to the axis of this antenna so that it could remain oriented toward the Earth.<ref name=prd65_8/> Each transceiver is an 8&nbsp;W one and transmits data across the [[S-band]] using 2110&nbsp;MHz for the uplink from Earth and 2292&nbsp;MHz for the downlink to Earth with the [[Deep Space Network]] tracking the signal. Data to be transmitted is passed through a [[convolution code|convolutional encoder]] so that most communication errors could be [[error detection and correction|corrected]] by the receiving equipment on Earth.<ref name="NASA_sp349_396"/>{{rp|43}} The data transmission rate at launch was 256&nbsp;bit/s, with the rate degrading by about 1.27&nbsp;millibit/s for each day during the mission.<ref name=prd65_8/>

Much of the computation for the mission is performed on Earth and transmitted to the spacecraft, where it was able to retain in memory up to five commands of the 222 possible entries by ground controllers. The spacecraft includes two command decoders and a command distribution unit, a very limited form of a processor, to direct operations on the spacecraft. This system requires that mission operators prepare commands long in advance of transmitting them to the probe. A data storage unit is included to record up to 6,144&nbsp;[[bytes]] of information gathered by the instruments. The digital telemetry unit is used to prepare the collected data in one of the thirteen possible formats before transmitting it back to Earth.<ref name="NASA_sp349_396"/>{{rp|38}}