The second space probe used to study Jupiter and the outer solar system
This entry is missingOverview, add relevant content to make the entry more complete, and it can also be upgraded quickly. Hurry upeditCome on!
Pioneer 11 (Pioneer 11) is the second one used to study Jupiter andOuter solar systemOfSpace probe。It is also the first probe to study Saturn and its rings.AndPioneer 10 The difference is that Pioneer 11 (also known as Pioneer G) not only visited Jupiter.It also used Jupiter's strong gravity to change its orbit to Saturn.When it approaches Saturn, it follows its escape orbit and leaves the solar system.
The detector was located on April 6, 1973FloridaFrom Cape Canaveral.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 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.
structure
Announce
edit
The detector is also equipped with three sensors: the star (old planet) sensor and two sun sensors to calculate the position of the detector according to the position relative to the earth and the sun, and the position of old planet as a backup.The star sensor and starting point of Pioneer 11 are set according toPioneer 10Has 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 continue to ignite or suspend the ignition point according to the command.
The instrument on the detector is responsible for studying interstellar and planetary magnetic fields, solar wind, cosmic rays, transition regions of the solar sphere, and a large number of neutral hydrogen;Distribution, size, mass, flux and velocity of stardust particles;The outer solar system planet auroras, radio waves, the atmosphere of its satellites;And the surfaces of Jupiter, Saturn and their moons.
The above research mainly consists of the magnetometer on the detector, plasma analyzer (dedicated to solar wind), particle sensor, ion sensor, a non image telescope that can overlap different viewpoints to detect the sunlight refracted by passing meteorites, some sealed and pressurized argon and nitrogen to calculate the penetration of meteorites, ultraviolet meter, infrared meterAnd an image polarimeter for taking pictures and calculating light polarization, etc.Further data are calculated from celestial mechanics and occultation phenomena.
Visit Jupiter
Announce
edit
The probe was closest to Jupiter on December 4, 1974JupiterThe highest cloud layer is within 34000km.With Jupiter's strong gravity, the probe changed its orbit to Saturn.
Visit Saturn
Announce
edit
The probe was closest to Saturn on September 1, 1979SaturnThe highest cloud layer is within 21000km.
(At that timeVoyager 1andVoyager 2Has passed Jupiter and is heading for Saturn)Pioneer 11 It 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 still a dim halo that will damage the detector in this area.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 miss the opportunity to visit Uranus and Neptune.
In fact, the detector uses a spare transmission antenna just after the transmission.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 isotopeAfter the energy provided by the thermoelectric generator was insufficient for any further experiment, the operation of the detector and the telemetry data were terminated on September 30, 1995.Before the termination of operation, the detector was at a distance of about 44.7 astronomical units from the sun, formed a 17.4 degree tilt angle with the equatorial surface of the sun, and was flying at a speed of 2.5 astronomical units (12 kilometers per second) every year.
abnormal
Announce
edit
ByPioneer 10 According to the analysis of the radio tracking data sent back from No. 11, when the detector is 20 to 70 astronomical units away from the sun, its signal has some slightly abnormal Doppler frequency drift phenomenon.This drift makes the detector decelerate at an acceleration of (8.74 ± 1.33) × 10 − 10m/s2.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 a physical law that has not yet been discovered.
Mysteriously blocked
Announce
edit
When the researchers first conducted the abnormal analysis of Pioneer, although they used the observation records of Pioneer 11 in the past four years, it was only equivalent toPioneer 10Data for the past 11 and a half years.After the pursuit and search action initiated by the Planetary Society, Tulshev and his team regained the complete remote sensing record data of the two Pioneer spacecraft, including the data of Pioneer 10 for nearly 30 years and Pioneer 11 for nearly 20 years.At that time, they were 20-70 AU away from the sun.AU is the distance from the sun to the earth, about 150 million kilometers.
Most of the data were recorded on nearly 40 tapes stored in depth in the Jet Lab.In short, there are nearly 40 gigabytes of Pioneer 10 and 11 mission data, equivalent to half an hour of high-definition TV programs.They converted the data from magnetic tape to modern digital mode and projected it to restore the old appearance of spacecraft and other damaged materials.For the researchers of Pioneer's anomaly analysis, this work is quite time-consuming and may be futile.But Tulshev still firmly believes that once this information is used for analysis, this abnormal phenomenon will reveal new secrets.
Tulshev also insisted on watching the operation of NASA's New Horizon detector. Maybe one day it will appear this abnormal phenomenon, but if the mysterious force is found to be a real effect, we don't need to make a fuss about it."The only thing we can do now is to recover these new data," Tulshev said. "Let these data be analyzed before we talk about it."
Scientists said that the same phenomenon also occurred on the Galileo and Ulysses spacecraft.GalileoIt was launched in 1989 to study Jupiter.It reached Jupiter on December 7, 1995.After successfully completing its flight, it was sent to a deliberately destroyed orbit of Jupiter on September 21, 2003.Ulysses was launched in October 1990 and reached Jupiter in February 1992.Later, it successfully studied Jupiter, comets and other celestial bodies.This task has been postponed to 2008.
