Pioneer 11 is the second one used for researchJupiterandOuter solar systemOfSpace probe。It is also the first probe to study Saturn and its rings.AndPioneer 10 The difference is that Pioneer 11 (also called Pioneer G) not only visited Jupiter, but also used Jupiter's strong gravity to change its orbitSaturn。After it approached Saturn, it followed its escape orbit and leftsolar system。
Pioneer 11 was located on April 6, 1973FloridaOfCape CanaveralLaunch.The total length of the detector is 2.9m, and a 2.74m diameterHigh gain antenna, install another one before itGain antenna。The other omnidirectional low gain antenna is installed on the high gain antennareceiverBelow.The detector consists of twoRadioisotope thermal motor（RTG）As an energy source, 144 watts can still be generated when visiting Jupiter, but only 100 watts can be generated when reaching Saturn.[1]
On Jupiter
The probe was closest to Jupiter on December 4, 1974. Within 34000 kilometers from the highest cloud layer of Jupiter, the probe changed its orbit to Saturn by the strong gravity of Jupiter.
Explore Saturn
Pioneer 11
The probe was closest to Saturn on September 1, 1979, within 21000 kilometers of Saturn's highest cloud layer.(At that timeVoyager 1andVoyager 2Has passed Jupiter and is heading towards Saturn) Pioneer 11 is set to fly over Saturn's halo, and its orbit will be the same as that of the upcoming travelers, for testingTraveler detectorTrack.Because Pioneer 11 can test whether there is a dim halo in the area that will damage the detector.So Pioneer 11, just like its name, is a "Pioneer".If a danger is detected, the Voyager probe will change its orbit to leave those rings, but will lose its visitUranusandNeptuneOpportunities.
Pioneer 11
In fact, the detector is used as a backup after launchTransmitting antenna。The detector began to share power with other instruments in February 1985 because the power provided by the battery began to decline.Ultimately, based onradio isotopeThe energy provided by the thermoelectric generator is not enough for the operation of the detector andTelemetry dataThe transmission was terminated on September 30, 1995.Before the termination of operation, the probe was about 44.7 hours away from the sunAstronomical unitDistance from the sunEquatorial surfaceForming 17.4 degreesInclination angleAt a speed of 2.5 astronomical units per year (12 kilometers per second)AquilaAnd will arrive there in 4 million years.
structural analysis
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The total length of the detector is 2.9m, and a 2.74m diameterHigh gain antenna, install a medium gain antenna before it.The other omnidirectional low gain antenna is installed under the high gain antenna receiver.The detector consists of two piecesradio isotopeThe thermoelectric generator (RTG), as an energy source, can still produce 144 watts when visiting Jupiter, but can only produce 100 watts when reaching Saturn.
The detector is also equipped with threea sensor: Stars（Elderly Star）The sensor and two sun sensors are used to calculate the location of the detector according to the position of the newly discovered stars relative to the earth and the sun.The star sensor and starting point of Pioneer 11 are set according toPioneer 10 Has been revised.Three pairs on the detectorRocket thruster, responsible for controlling the rotating shaft (4.8 rpm) and providing power for the detector.All three pairs of rocket propellers can be ignited continuously or stopped burning as instructed.
The above research is mainly based on theMagnetometer、plasmaanalyzer(dedicated to solar wind), particle sensorIon sensorA non image telescope that can detect light refracted by meteorites by overlapping different viewpoints, and some sealed and pressurized argon and nitrogen are used to calculate the penetration and measurement of meteoritesultravioletMeasurementinfrared lightAnd an image polarimeter forTake photosAnd calculate light deflection, light vibration, etc.As for further dataCelestial mechanicsandOccultation methodPhenomenon to calculate.
Gold plated aluminum plate
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And its sister detectorsPioneer 10 Similarly, Pioneer 11 also carried a piece of gold-plated aluminum plate containing human information.If the detector is captured by intelligent extraterrestrial creatures, this gold-plated aluminum plate will explain the source of the detector to them.An image of a man and a woman is painted on the aluminum plate,hydrogen atomThe spin transition of the sun and the earthGalaxyPosition in.stayPioneer detectorThe idea of putting gilded aluminum plates on the top to convey human messages was originally conceived by Eric Burgess in theSailor PlanVisit atCaliforniaPasadenaJet Propulsion LaboratoryProposed at.At that time, he and Hoagland went to find Zeng inCrimeaA famous astronomer who gave a speech at a conference on communication with extraterrestrial intelligent creaturesCarl Sagan The results of the doctor's conversation (see“Pioneer plaques ”Entry).
Anomaly analysis
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ByPioneer 10 And the radio tracking data sent back from No. 11. When the detector is 20 to 70 away from the sunAstronomical unitThe signal is slightly abnormalDopplerFrequency driftPhenomenon appears.This kind of drift makes the detector continuously increase the detection rate by (8.74 ± 1.33) × 10 ^ − 10 m/s ^ 2accelerationSlow down.In other words, it seems that an external force forced the pioneer probe ship to slow down.Scientists have talked about this phenomenon. Some people pointed out that this phenomenon is caused by a variety of factors, but others pointed out that it may be an undiscovered phenomenonLaws of physics。
Current status
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On March 6, 2011, Pioneer 11 was about 82.805 away from the sunAstronomical unit；Presents an ellipse latitude of 14.3 degreesdeflection-8.73 degrees.At a speed of 11.415 kilometers per second (2.408 astronomical units per year);Pioneer 11 was also inRight ascension18.759 hours,sunlightIt will take 11.54 hours to reach the position as far as Pioneer 11;It is towardsPioneer 10 In the opposite direction (towardsShield pedestalIn view of the fact that Pioneer 10 is heading towards leaving the center of the Milky Way, Pioneer 11 is heading towards the center of the Milky Way.
