Pioneer 10

from Wikipedia, the free encyclopedia
Pioneer 10

Pioneer 10 during final assembly
NSSDC ID 1972-012A
Mission goal Penetrating the asteroid belt and exploring Jupiter
Client National Aeronautics and Space AdministrationNASA NASA
Launcher Atlas Centaur
construction
Takeoff mass 258 kg
Instruments

AMA, CPI, CRS, GTT, HVM, IPP, IR, MD, PA, TRD, UV

Course of the mission
Start date March 3, 1972, 1:49 UTC
launch pad CC , LC-36B
End date January 2003
 
 03/03/1972 begin
 
 December 3, 1973 Passage of Jupiter
 
 1976 Passage of the Saturn orbit
 
 1979 Passage of the Uranus orbit
 
 06/13/1983 Passage of the Neptune Railway
 
 01/23/2003 Last contact with the probe
 
 The probe will leave the solar system
Artist's impression of the Pioneer 10 in space

Pioneer 10 is the first human-built spacecraft to reach the planet Jupiter and then the outer reaches of the solar system. It was part of the Pioneer program on 3 March 1972 by the Launch Complex 36 on Cape Canaveral with an Atlas - Centaur launch rocket. The probe has produced numerous scientific findings about the planet Jupiter, the asteroid belt, but also in the outer regions of the solar system. Pioneer 10 proved extremely robust and last sent data back to Earth in January 2003. With a mission duration of almost 31 years, it exceeded its planned lifespan of 21 months by more than sixteen times.

Planning and mission goals

As early as the 1960s, numerous scientists were busy with possible missions to the outer planets , especially to Jupiter, as it was recognized that its strong gravity can be used to accelerate space probes without using fuel by means of so-called swing-by . NASA approved a program for two identical probes in February 1969. These were assigned to the Pioneer series and were named Pioneer F and Pioneer G, respectively . The program was led by the Pioneer Project Office at the Ames Research Center , and the probes were to be developed and designed by TRW . Jupiter has an optimal launch window every 13 months , so the first probe should be launched in February or March 1972, and the second 13 months later. The exact responsibilities were as follows:

The mission objectives of the Pioneer probes focused on the area beyond Mars. The asteroid belt should be scientifically researched and at the same time its danger for space vehicles should be determined. The interplanetary medium between Mars and Jupiter was also of great scientific interest. Finally, Jupiter itself should also be studied intensively. The Pioneer probes required the fastest possible speed any man-made object would ever reach. Therefore, the most powerful launcher available at the time , an Atlas rocket with a Centaur upper stage, was chosen. Since the thrust was still insufficient, a third solid stage was also integrated, with which the necessary speed of over 14.3 km / s could be achieved.

technology

Pioneer 10 was primarily made of aluminum and weighed 258 kg at launch, 28 kg of which was accounted for by hydrazine as a fuel for attitude control. The central part of the probe consists of a hexagonal ring that houses the majority of the electronics and is made of aluminum in a sandwich honeycomb construction . The hexagon has a depth of 25.5 cm and a side length of 71 cm. On top of it is the conspicuous parabolic antenna with a diameter of 2.74 m. Three arms are symmetrically attached to the central part. Two of them carry two radionuclide batteries each three meters away (see energy supply ) in order to reduce interference from their radiation. The HVM instrument is located on the third, 6.6 m long boom . In the center of the ring there is a heated spherical tank with a diameter of 42 cm for the hydrazine.

power supply

Scheme of a SNAP-19 radionuclide battery

Pioneer 10 was the first probe to draw its energy exclusively from a thermoelectric radionuclide battery . This innovation was necessary because Jupiter's solar radiation is 27 times less than that of Earth, which means that solar cells would be impractical due to the required area of ​​around 23 m². The four batteries of Pioneer 10 are filled with the isotope plutonium-238 , which has a half-life of 87.7 years and emits alpha radiation during decay . This radiation releases large amounts of heat (temperature typically several hundred degrees Celsius). This heat is converted directly into electrical energy with 90 thermocouples per battery . The batteries are of the type SNAP-19 , which was also used in the Viking probes, weigh 15.4 kg each and have the dimensions 58 cm × 38 cm . When started, all batteries together generated 155  W , which sank to 140 W due to the plutonium decay and the wear and tear of the thermocouples by Jupiter. By 2004 the level had dropped to just 65 W. Pioneer 10 consumes a maximum of 106 W, of which 26 W were used for the scientific instruments. The board voltage is 28  V .

communication

Communication took place primarily via the large high gain antenna, which has a diameter of 2.74 m and an opening angle of 3.3 °. It achieved an antenna gain of 38  dB . This achieved a transmission rate of 2  kbit / s in the asteroid belt and 1 kbit / s with Jupiter. In general, the transmission rate could be selected in 16 steps from 0.016 kbit / s to 2 kbit / s. The reception rate was very low with Jupiter with only one bit per second. There is also a medium gain antenna on the receiver, which could send and receive data even with an imprecise alignment to the earth. Should the probe not be able to carry out any alignment to the earth, there is a low-gain antenna on the other side, which could transmit and receive in a much larger area (32 ° opening angle ), albeit at extremely low transmission rates. This results from the very low antenna gain of only 21  dB . Therefore, it is only intended for emergency communication and was not used to transmit scientific data. All transmissions took place in the S-band at 2.110 or 2.292  GHz , whereby the two redundant transmitters each have a transmission power of 8 W and weigh 1.75 kg.

electronics

Like earlier space probes, the Pioneer 10 has hardly any automatic control systems and therefore had to be constantly supplied with commands from the ground station . There are a total of 222 commands, 73 of which are used to control the scientific instruments and 149 to control the probe. Each command is 22 bits long, so the transmission took 22 seconds when the probe was in Jupiter's range. However, this data rate was not sufficient for some situations in which several commands had to be executed in quick succession . Therefore, a memory was built in that could hold up to five commands. The scientific instruments have a memory with a total capacity of 50 kbit and can handle 18 different data formats. One of the few automatic components of the probe is the CONSCAN system. With the help of the minimum bearing , it can align the antenna autonomously to the earth. However, manual alignment using commands from the ground station is more effective in terms of fuel consumption, which is why CONSCAN mode was rarely used.

Flight control

To determine the position of the probe, three star sensors are used, two of which target the sun and one Canopus as guide stars . If one of the two stars moves out of the field of vision of the sensors, a correction of the position is initiated. This is carried out by twelve thrust nozzles arranged in pairs, which are located on the antenna dish. You can use a boost generate 1.8 to 6.2 Newton. The stability of the probe is ensured by its own rotation of around 4 to 5 revolutions per minute, the speed of rotation falling over time. The rotation takes place around the axis transmitter-antenna-central ring. The thrusters are also used to adjust the rotation.

plaque

The Pioneer badge

The Pioneer 10 badge is intended as an information carrier for aliens who might find the probe. It measures 22.9 cm in width and 15.2 cm in height. A 1.2 mm thick aluminum plate, which is coated with gold for corrosion protection, serves as the base material . Primary elements of the picture are a man and a woman, each unclothed, and the silhouette of the spaceship to enable a size comparison. The position of the earth is given relative to fourteen pulsars . Furthermore, the solar system and a hyperfine structure transition of a hydrogen atom are shown.

Scientific instruments

Diagram of Pioneer 10 and its systems

Pioneer 10 carried a total of 11 scientific instruments, whereby the "S-band experiment" is not counted as an independent system.

instrument Manufacturer Dimensions consumption
Asteroid / Meteoroid Astronomy (AMA) General Electric 3.3 kg 2.7 W.
Meteoroid Detectors (MD) Langley Research Center 1.7 kg 0.7 W
Imaging Photopolarimeter (IPP) University of Arizona 4.3 kg 2.2 W
Infrared Radiometers (IR) Caltech 2.0 kg 1.3 W
Ultraviolet Photometry (UV) University of California 0.7 kg 0.7 W
Charged Particle Instrument (CPI) University of Chicago 3.0 kg 2.4 W.
Trapped Radiation Detector (TRD) University of California 1.7 kg 2.9 W
Cosmic-Ray Spectra (CRS) Goddard Space Center 3.2 kg 2.2 W
Geiger Tube Telescope (GTT) University of Iowa 1.6 kg 0.7 W
Helium Vector Magnetometer (HVM) Jet Propulsion Laboratory 2.6 kg 5.0 W.
Quadrispherical Plasma Analyzer (PA) Ames Space Center 5.5 kg 4.0 W
total 29.6 kg 24.3 W

Asteroid / Meteoroid Astronomy (AMA)

The four telescopes of the AMA

This instrument measured the distribution of large and small boulders in the asteroid belt. For this purpose, four Ritchey-Chrétien-Cassegrain telescopes were used, each arranged at an angle of 45 ° to the axis of rotation. All telescopes had a focal length and diameter of 20 cm . Due to the short focal length, the field of view was 7.5 °. The incident light, which was reflected by the asteroids, was amplified by means of photocathodes and photomultiplier tubes . A measurement was triggered when an object was detected by at least three of the telescopes. The speed of the object was calculated by comparing the times of detection by the individual telescopes. The size was calculated from the amount of reflected light. The instrument failed in December 1973, at which point the asteroid belt had already been crossed.

Meteoroid Detectors (MD)

A meteoroid detector (above) and its distribution on the underside of the antenna (below)

The meteoroid detector supplemented the AMA and registered the impact of particles on the probe that weighed over 100 nanograms. For this purpose, 234 cells were filled with an argon - nitrogen mixture. When a particle penetrated the 0.05 mm thick film, the gas flowed out. This was detected by a cathode , which also ionized the gas. This also made it possible to determine the size of the impacted particle. The instrument had a total area of ​​2.45 m², with several detector plates being attached to the rear of the antenna (see picture on the right). In October 1980 the instrument was finally switched off.

Imaging Photopolarimeter (IPP)

This instrument was responsible for all photographic recordings in visible light. It used a Maksutov telescope with a diameter of 2.54 cm and a focal length of 86 mm. A calcite - Wollaston prism split the incoming light into two separate beams, which were then directed through two mirrors and two filters (blue: 390 to 490 nm, red: 580 to 700 nm) onto several photomultiplier tubes for amplification, which then generated the light digitized . It was also possible to determine the polarization and the temperature of a 0.46 ° image section, using a tungsten lamp for calibration . In the imaging mode, the instrument achieved a resolution of 0.5  mrad .

The IPP instrument

6 bits of brightness information per color were available for each pixel. The image was always 512 pixels wide and the height could be set to 128, 256 or 512 pixels. For the subsequent reading out of the 6144 byte memory, 12 seconds were available. This enabled the IPP to achieve data rates of up to 0.5 kbit / s, which corresponds to half of the transmission capacity at Jupiter. With a maximum image size of 3.15 Mbit, the transmission of an image could take up to 100 minutes. This caused considerable problems during the subsequent image processing by the ground station, since the green color channel had to be added synthetically and the strong distortions caused by the rotation of the planet could only be removed with complicated calculations. The IPP was activated periodically after its primary mission to measure star positions, as the two star sensors were increasingly unable to detect their reference star due to the increasing distance. Image errors occurred in October 1991, which is why it could no longer work in this function. To save electricity, the instrument was completely switched off three years later.

Infrared Radiometers (IR)

The IR instrument

This instrument measured the surface temperature of planets by evaluating the infrared radiation emitted . It was an evolution of the system used on Mariner 6 and 7 and had a higher resolution by comparison. It had a Cassegrain telescope with a diameter of 7.62 cm and a field of view of 1 ° × 3 °. A total of 88 bimetal thermophile sensors were used for measurements; radiation in the wavelength range from 14 to 56 μm was measured. At the closest approach to Jupiter, the field of view was 725 km × 2400 km, which allowed a rough mapping of the temperature regions of the planet.

Ultraviolet Photometry (UV)

The UV instrument (above) and the functional diagram (below)

This instrument was used for the broadband measurement of ultraviolet radiation . It could detect wavelengths from 20 to 180 nm and was equipped with two filters for 121.6 and 58.4 nm. The spectral lines of hydrogen and helium could be recognized by means of these filters . A photometer with an opening angle of 20 ° was used as a detector . In interplanetary space, the instrument searched for radiation that was caused when hydrogen atoms were slowed down to subsonic speed and when ions collided with them. In December 1990, it was found that the charging capacity of the instrument was decreasing, which limited the useful life to a maximum of two days per week.

Charged Particle Instrument (CPI)

The CPI analyzed charged particles with the help of four sensors, two of which were responsible for interplanetary space and two for particles near Jupiter. The main detector, which worked with a sapphire crystal, was able to create an energy spectrum of 3 to 68 MeV for protons and 10 to 150 MeV per nucleon for oxygen . He could also see ionized elements down to the atomic mass of oxygen. It was also able to determine the isotopic composition of hydrogen and helium. This detector was designed for interplanetary space. The low-energy particle sensor was also used in this environment. It was based on cesium iodide and used a thin metal plate to measure low energy protons (0.3-0.9 MeV). The field of view was 70 °.

The CPI instrument

An electron current detector was used in the vicinity of Jupiter and Saturn. He used a silicon sensor for the measurement , which was shielded by a beryllium plate, which only let through electrons with high energy (over 3 MeV). The fourth detector was also intended for the space near the planets and looked for high-energy protons above 30 MeV. For this purpose, a thorium 232 element was placed between two silicon-based sensors. This enabled them to selectively measure the radiation produced by the reaction product uranium- 233 when it spontaneously decays without the influence of the electrons. The measurement was divided into eight 45 ° sectors.

Trapped Radiation Detector (TRD)

The TRD instrument with its five telescopes

This instrument consists of five detectors for electrons and protons. The first was a Cherenkov counter that used four channels to respond to particles with an energy of over 1, 6, 9, and 13 MeV, respectively. A three-channel electron scattering counter could detect electrons greater than 0.16, 0.26, and 0.46 MeV, respectively. A minimum ionization counter, which examined the cosmic background radiation , also worked on three channels . He detected electrons with more than 35 MeV and protons with more than 80 MeV. The last two sensors were scintillation counters , which recognized protons from an energy of 150 keV and electrons from 10 keV. The instrument could be read out with eight different data rates. A maximum of one channel could be read out in 1.5 seconds, which means that a complete cycle lasted at least 108 seconds. In the course of the mission, both scintillation counters and one channel of the Cherenkov counter failed because they used the same electronic components that had failed relatively early. To save electricity, the instrument was switched off on December 1, 1993.

Cosmic-Ray Spectra (CRS)

The CRS instrument

The CRS essentially consisted of three particle telescopes. The first measured high energy particles and consisted of five individual detectors. If these had an energy of 20 to 50 MeV per nucleon they were stopped, at higher energy they broke through the detectors. A maximum charge of up to 200 MeV could be measured. The other two telescopes captured low-energy particles. One could stop ions with an energy of 3 to 32 MeV and determine their charge and mass, with a measurement resolution of 20%. The last telescope could measure electrons in the range of 50 to 1000 keV as well as protons with an energy of 0.05 to 20 MeV. The resolution here was 20%. The entire instrument detected particles in eight sectors of 45 ° each.

Geiger Tube Telescope (GTT)

The GTT instrument

This Geiger counter was used to measure protons and electrons and to determine their place of origin. In order to achieve this, three detectors were arranged orthogonally to one another, so that one measured value was determined for each coordinate axis in three-dimensional space, which enabled tracing back. In order to filter out the background noise of the universe, there was another tube to measure it. The electronics could then use this measurement to remove the noise from the other detector readings. There were two of these sensor complexes that covered different energy ranges. The first complex recognized electrons with an energy of 5 to 21 MeV and 30 to 77.5 MeV for protons, the second electrons in the range of 0.55 to 21 MeV and protons at 6.6 to 77.5 MeV. A last tube was covered with a gold foil that did not allow any protons to pass, but electrons with an energy of over 60 keV. The GTT, which was developed by the well-known space pioneer James Van Allen , was the last instrument that was switched off due to a lack of energy.

S-band experiment

The S-band experiment is not counted as a separate instrument as it used all the hardware of the high gain antenna. It used its S-band transmitter to directly illuminate the atmosphere of planets and moons. When walking through the atmosphere , the signal changed due to interactions with its molecules, which made it possible to draw conclusions about their structure, density and temperature. Since the gravitational forces slightly changed the frequency of the radio waves, it was also possible to determine the density of the entire celestial body. For Jupiter's moon Europa , the deviation from the value determined later was approx. 8%, with Pioneer 11 later achieving deviations of less than one percent.

Helium Vector Magnetometer (HVM)

Parts of the HVM instrument

This instrument was used to measure magnetic fields. The sensor is attached to one of the three booms at a distance of 6.6 meters from the cell in order to minimize interference from the radionuclide batteries, the on-board electronics and the probe's own magnetic field. The central part of the HVM is filled with helium . The gas was charged differently by magnetic fields, which changed its absorption properties. This change is measured by an infrared sensor and then interpreted accordingly. The sensitivity was 4 to 0.01  nT , the maximum magnetic fields could be measured with a strength of 140 μT, which corresponds to three times the earth's magnetic field near the ground. The measuring ranges could be regulated in eight steps, whereby the probe could also adapt them automatically. The instrument kept data until November 1975 and was finally shut down in June 1986.

Quadrispherical Plasma Analyzer (PA)

The PA instrument

This instrument was used to measure particles with very low energy and has a measuring channel with medium and high resolution. The latter was able to detect electrons in the range from 1 to 500 eV and protons with an energy of 0.1 to 18 keV. Before the measurement, the particles were accelerated over a distance of 9 cm by means of 26  channel electron multipliers at a voltage of 9 kV. The detectors, which were arranged in a semicircle and had a field of view of 51 °, then only registered particles which had a charge corresponding to a voltage of 0.1 to 8 kV. The medium resolution channel had an entrance opening of 12 cm and covered an angle of incidence of 15 to 22.5 °. The acceleration path was only one centimeter, and only protons with an equivalent voltage of 0.1 to 18 kV were measured. Electrons were detected in the range from 1 to 500 volts. The instrument was shut down in September 1995.

Course of the mission

begin

Launch of Pioneer 10 with the Atlas rocket

Since Pioneer 10 had to reach a high escape speed to get to Jupiter , a powerful launcher was needed. An Atlas rocket with a Centaur upper stage was chosen. In addition, a "Star 37E" solids upper stage was used. It weighed 1127 kg and delivered a thrust of 66.7 kN over a period of 43 seconds. This probe was launched on March 3, 1972 at 1:49  UTC from Launch Complex 36 of Cape Canaveral AFB . Unlike many previous probes, Pioneer 10 was put directly on a course to Jupiter instead of being put into parking orbit first. With a speed of 14.36 kilometers per second, it exceeded the speed of the Apollo spacecraft . It took them three days to orbit the moon, Pioneer 10 only eleven hours.

First flight phase and asteroid belt

Pioneer 10 achieved important scientific results early on. For the first time , the zodiacal light could be detected from far beyond the earth. In August 1972, a solar storm occurred , which Pioneer 9 and 10 could simultaneously observe and measure. In February 1973, the probe became the first human-made object to reach the asteroid belt . This was completely new territory, even particles with a diameter of 0.05 mm could seriously damage the probe. At the time it was suspected that the asteroid belt could make an advance towards Jupiter impossible. It turned out, however, that this assumption was completely exaggerated, because the AMA instrument could neither detect large asteroids, nor could the MD system report many impacts. The closest approach to a cataloged object ( asteroids from the Palomar-Leiden group ) was 8.8 million kilometers. Thus one could practically rule out the asteroid belt as a serious danger to future spaceships. Approximately 16,000 commands were sent to the probe during the entire journey to Jupiter.

Jupiter

Jupiter with the "big red spot"

In November 1973, Pioneer 10 reached the Jupiter system when it crossed the orbit of the outermost then known moon, Sinope . The closest approach to Jupiter took place on December 3, 1973. On November 26th, the probe entered the bow shock wave of Jupiter's magnetosphere , which was recognized by the rapid decrease in speed (from 451 km / s to 225 km / s) and the greatly increased temperature of the solar wind . When Pioneer 10 crossed this zone within a day, the solar wind was no longer measurable due to Jupiter's strong magnetic field, whose flux density was 5 nT. Since there was increased solar activity a few days earlier , this magnetic field was temporarily compressed on November 29th, so that the probe came into contact with solar particles for another 11 hours. On December 1, the probe was finally within the magnetic field of Jupiter, which was 3.5 million kilometers away. Now they started taking the photos, 95 hours before the next approach. Due to the camera's large field of view, the planet was only full format eight hours before the closest approach. 74 hours after the approach, the operation of the IPP was stopped and 180 pictures could be taken. On December 3, 1973, Pioneer 10 did not receive some commands due to the strong radiation, which meant that the IPP did not photograph the moon Io . During the passage through the radiation belt , the probe received a radiation dose that was 1000 times higher than the dose that was lethal for humans . Nevertheless, one image each of the moons Ganymede , Europa and Callisto was possible . Due to the almost completely manual control of the probe, 400 to 2000 commands were sent per day in the Jupiter system.

Several low-resolution images of four moons of Jupiter

Thanks to Pioneer 10, it was possible to analyze Jupiter's structure much better than with the earth-based instruments of the time. So she found a smaller counterpart to the Great Red Spot , which had been discovered earlier from Earth. However, with the arrival of Pioneer 11, this new spot was gone. Temperature measurements showed that the bright zones of the planet were 6 Kelvin cooler than the dark ones, which can be explained by their higher albedo value. As suspected, Jupiter radiated 2.5 times more energy than it absorbed from solar radiation. In the strong radiation belt of the planet, up to 13 million high-energy electrons per cubic centimeter were measured, with protons the concentration was up to 4 million protons / cm³. In the case of the low-energy electrons, the density increased to up to 500 million electrons / cm³, which was 5000 times more than in the Van Allen Belt . The atmosphere was carefully examined and the helium content, pressure and temperature could be determined. The temperature minimum of −163 ° C was reached at a pressure of 0.03 bar. The HVM instrument measured the location, shape and strength of Jupiter's magnetic field, the influence of which extends to Saturn's orbit. In the upper cloud layers, the flux density of the field was 0.4 mT. Gravitational measurements revealed that the core of the planet is only very small and fluid. The S-band experiment could be used on the moon Io and a ground pressure of 0.05 mbar was determined, with the atmosphere being up to 115 km high. A pronounced ionosphere was also discovered on the moon , which extended 700 km on the day side and had an electron density of 60,000 electrons per cubic centimeter. On the night side it was much thinner with only 9000 electrons / cm³. A hydrogen cloud was also discovered between Ios orbit and Jupiter.

The probe approached Jupiter's cloud ceiling up to 130,354 kilometers and was further accelerated by the swing-by maneuver. As a result, the maximum speed reached was for a short time 132,000 km / h (= 36.67 km / s). Due to the immense mass of the planet, the trajectory of Pioneer 10 was deflected by almost 90 °, but it remained in the ecliptic .

After Jupiter

The trajectories of the Voyager and Pioneer probes

In 1976 Pioneer 10 passed the orbit of Saturn, in 1979 that of Uranus and 1983 that of Neptune. An exploration of these planets was not possible and also not planned because they were far from the orbit of the probe. Pioneer 10 remained the furthest man-made object until February 17, 1998. The Voyager 1 probe, launched in 1977, is now at a greater distance from Earth thanks to its higher speed.

Although Pioneer 10 was not designed for use outside of Jupiter's orbit, the instruments for measuring radiation and ions were generally also suitable for analyzing interplanetary space. The probe's low energy level soon became a problem, as the output of the radionuclide batteries was continuously decreasing, which is why more and more scientific instruments had to be switched off over time. The AMA system had to be switched off in December 1973 and the IR instrument followed in January 1974 . The magnetometer was then deactivated in November . In 1976 the main transmitter of the communication system failed, so that one had to switch to the reserve transmitter. The program memory was deactivated in September, also to save electricity. Because the operating temperature was too low, the meteorite detector could no longer be operated effectively and was switched off in October 1980. Since 1980 it has been observed that Pioneer 10 slightly deviated from the predicted course. This phenomenon is known as the Pioneer anomaly and has not been clarified for a long time, but is now attributed to the uneven heat radiation of the radionuclide batteries. Further problems with the system led to a drop in performance, so that one was forced to fall back on the large 70 m antennas of the Deep Space Network . These are the most powerful models of their kind, with which a data rate of 16 bit / s can be achieved. In November 1993 the TRD instrument was switched off, in December the undervoltage protection was switched off to save electricity. From now on, even small fluctuations in the electrical systems could mean a total failure. For this reason, the protection was switched on again temporarily when course corrections were made, as separate batteries were used. In September 1995 the plasma analyzer was deactivated so that only four instruments were active: UV , CPI , CRS and GTT .

To save money, Pioneer 10 was officially written off on March 31, 1997, although it was still functional. However, it was always possible to withdraw funds from other projects in order to make contact with the probe every now and then. The probe was then used to train ground controllers who used it to practice handling probes that had very long signal transit times (several hours). In addition, you also received scientific data. Due to the ever-decreasing energy level, one was still forced to switch off the last instruments. In January 2001, only the GTT system was then active. On February 10, 2000, Pioneer was able to receive a command for the last time (the probe reported a successful reception), as the increasing distance caused the reception strength to drop below a critical level. On April 27, 2002, usable data could be received from the probe for the last time.

The last identifiable signal was received on January 23, 2003, at the next planned contact on February 7, no signal could be detected by the probe and so the mission ended after 31 years at a distance of about 81  AU (about 12 billion kilometers) . Since then, the space probe has been moving approximately in the direction of the star Aldebaran, 67  light years away in the constellation Taurus , whose current position it will reach in around 2 million years.

Important stages of the mission and theoretically the future flight history of the probe ( italics = no verification possible due to the lack of communication)

Costs and benefits

The total cost for Pioneer 10 are provided by NASA with 350 million US dollars estimated, of which 200 million to development and construction and 150 million to the mission monitoring. Compared to later missions, the probe cost relatively little. Pioneer 10 provided important findings for the Voyager probes , the design and equipment of which were adapted accordingly. It was also shown that a safe passage through the asteroid belt was possible. For the first time, the probe also provided detailed images of Jupiter and its moons . With a mission time of 31 years with a planned 21 months, one can speak of a great success for NASA.

literature

  • Mark Wolverton: The Depths of Space: The Story of the Pioneer Planetary Probes . Joseph Henry Press, 2004, ISBN 0-309-09050-4 .
  • John D. Anderson, Philip A. Laing, Eunice L. Lau, Anthony S. Liu, Michael Martin Nieto and Slava G. Turyshev: Study of the anomalous acceleration of Pioneer 10 and 11 . In: Physical Review D . Volume 65, 2002, 082004, doi : 10.1103 / PhysRevD.65.082004 , arxiv : gr-qc / 0104064v5 .

Movie

In the science fiction film Star Trek V - On the Edge of the Universe , Pioneer 10 is used as a training target by a Klingon "Bird of Prey" spaceship and destroyed.

Web links

Commons : Pioneer 10  - collection of pictures, videos and audio files
Commons : Pioneer Missions  - collection of pictures, videos and audio files

Individual evidence

  1. ^ Pioneer 10 . NSSDC. Retrieved August 7, 2009.
  2. ^ Charged Particle Instrument (CPI). NASA , accessed September 23, 2016 .
  3. ↑ http://www.nasa.gov/centers/ames/missions/archive/pioneer.html NASA Pioneer
  4. ↑ JA Van Allen: Update on Pioneer 10 . University of Iowa, February 17, 1998.
  5. ↑ PIONEER 10 SPACECRAFT SENDS LAST SIGNAL (www.nasa.gov, February 25, 2003)
  6. ↑ NunyVanstta135: Captain Klaa destroys the Pioneer 10 probe for target practice (Star Trek 5 Scene). April 24, 2014, accessed May 12, 2016 .