Pioneer 11

Last updated

  Pioneer 11 ·   Earth  ·   Jupiter  ·   Saturn
  • Animation of Pioneer 11 trajectory around Jupiter.gif
    Animation of Pioneer 11's trajectory around Jupiter from November 30, 1974 to December 5, 1974
      Pioneer 11 ·   Jupiter  ·   Io  ·   Europa  ·   Ganymede  ·   Callisto
  • Animation of Pioneer 11 around Saturn.gif
    Animation of Pioneer 11 around Saturn
       Pioneer 11 ·  Saturn ·  Epimetheus ·  Janus ·  Mimas ·  Enceladus

    • Encounter with Jupiter

    Pioneer 11 flew past Jupiter in November and December 1974. During its closest approach, on December 2, it passed 42,828 kilometers (26,612 mi) above the cloud tops. The probe obtained detailed images of the Great Red Spot, transmitted the first images of the immense polar regions, and determined the mass of Jupiter's moon Callisto. Using the gravitational pull of Jupiter, a gravity assist was used to alter the trajectory of the probe towards Saturn and gain velocity. On April 16, 1975, following the Jupiter encounter, the micrometeoroid detector was turned off. [1]

    Commons-logo.svg Media related to Pioneer 11 Jupiter encounter at Wikimedia Commons

    Encounter with Saturn

    Pioneer 11
    An artist's impression of a Pioneer spacecraft on its way to interstellar space.jpg
    An artist's impression of Pioneer 11 on its way to interstellar space.
    Mission typePlanetary / Heliosphere exploration
    Operator NASA / Ames
    COSPAR ID 1973-019A OOjs UI icon edit-ltr-progressive.svg
    SATCAT no. 6421
    Website science.nasa.gov
    Mission duration22 years, 7 months and 19 days
    Spacecraft properties
    Manufacturer TRW
    Launch mass258.5 kg [1]
    Power155 watts (at launch)
    Start of mission
    Launch dateApril 6, 1973, 02:11:00 (1973-04-06UTC02:11Z) UTC [1]
    Rocket Atlas SLV-3D Centaur-D1A Star-37E
    Launch site Cape Canaveral LC-36B
    End of mission
    DisposalDecommissioned
    Last contactNovember 24, 1995 (1995-11-25)
    Flyby of Jupiter
    Closest approachDecember 3, 1974
    Distance43,000 kilometers (27,000 miles)

    Pioneer 11 passed by Saturn on September 1, 1979, at a distance of 21,000 km (13,000 mi) from Saturn's cloud tops. [29]

    By this time, Voyager 1 and Voyager 2 had already passed Jupiter and were en route to Saturn, so it was decided Pioneer 11 would pass through the Saturn ring plane at the same position Voyager 2 would later have to fly through in order to reach Uranus and Neptune. If there were faint ring particles capable of damaging a probe in that area, mission planners felt it was better to learn about it via Pioneer. [29] Thus, Pioneer 11 was acting as a "pioneer" in a true sense of the word; if danger were detected, then Voyager 2 could be redirected further away from the rings but miss the opportunity to visit the ice giants in the process.

    Pioneer 11 imaged—and nearly collided with—one of Saturn's small moons, passing at a distance of no more than 4,000 kilometers (2,500 mi). The object was tentatively identified as Epimetheus, a moon discovered the previous day from Pioneer's imaging, and suspected from earlier observations by Earth-based telescopes. After the Voyager flybys, it became known that there are two similarly sized moons (Epimetheus and Janus) in the same orbit, so there is some uncertainty about which one was the object of Pioneer's near-miss. Pioneer 11 encountered Janus on September 1, 1979, at 14:52  UTC, at a distance of 2,500 km (1,600 mi). At 16:20 UTC the same day, Pioneer 11 encountered Mimas at a distance of 103,000 km (64,000 mi).

    Besides Epimetheus, instruments located another previously undiscovered small moon and an additional ring, charted Saturn's magnetosphere and magnetic field, and found its planet-size moon, Titan, to be too cold for life. Hurtling underneath the ring plane, the probe sent back pictures of Saturn's rings. The rings, which normally seem bright when observed from Earth, appeared dark in the Pioneer pictures, and the dark gaps in the rings seen from Earth appeared as bright rings.

    Commons-logo.svg Media related to Pioneer 11 Saturn encounter at Wikimedia Commons

    Interstellar mission

    On February 25, 1990, Pioneer 11 became the fourth human-made object to pass beyond the orbit of the planets. [30]

    By 1995, Pioneer 11 could no longer power any of its detectors, so the decision was made to shut it down. [31] On September 29, 1995, NASA's Ames Research Center, responsible for managing the project, issued a press release that began, "After nearly 22 years of exploration out to the farthest reaches of the Solar System, one of the most durable and productive space missions in history will come to a close." It indicated NASA would use its Deep Space Network antennas to listen "once or twice a month" for the spacecraft's signal, until "some time in late 1996" when "its transmitter will fall silent altogether." NASA Administrator Daniel Goldin characterized Pioneer 11 as "the little spacecraft that could, a venerable explorer that has taught us a great deal about the Solar System and, in the end, about our own innate drive to learn. Pioneer 11 is what NASA is all about – exploration beyond the frontier." [32] Besides announcing the end of operations, the dispatch provided a historical list of Pioneer 11 mission achievements.

    NASA terminated routine contact with the spacecraft on September 30, 1995, but continued to make contact for about two hours every two to four weeks. [31] Scientists received a few minutes of good engineering data on November 24, 1995, but then lost final contact once Earth moved out of view of the spacecraft's antenna. [1] [33]

    Timeline

    Pioneer 10 and 11 speed and distance from the Sun Pioneer speed and distance from Sun.svg
    Pioneer 10 and 11 speed and distance from the Sun
    Heliocentric positions of the five interstellar probes (squares) and other bodies (circles) until 2020, with launch and flyby dates. Markers denote positions on 1 January of each year, with every fifth year labelled. Plot 1 is viewed from the north ecliptic pole, to scale. Plots 2 to 4 are third-angle projections at 20% scale. In the SVG file, hover over a trajectory or orbit to highlight it and its associated launches and flybys. Interstellar probes trajectory.svg
    Heliocentric positions of the five interstellar probes (squares) and other bodies (circles) until 2020, with launch and flyby dates. Markers denote positions on 1 January of each year, with every fifth year labelled.
    Plot 1 is viewed from the north ecliptic pole, to scale.
    Plots 2 to 4 are third-angle projections at 20% scale.
    In the SVG file, hover over a trajectory or orbit to highlight it and its associated launches and flybys.
    Timeline of travel
    DateEvent
    1973-04-06
    		Spacecraft launched at 02:11:00.
    1974-04-19
    		Passage through the asteroid belt.
    1974-11-03
    		Start Jupiter observation phase.
    TimeEvent
    1974-12-02
    		Encounter with Jovian system.
    08:21:00
    		 Callisto flyby at 786,500 km.
    22:09:00
    		 Ganymede flyby at 692,300 km.
    1974-12-03
    03:11:00
    		 Io flyby at 314,000 km.
    04:15:00
    		 Europa flyby at 586,700 km.
    05:00:21
    		Jupiter shadow entry.
    05:01:01
    		Jupiter occultation entry.
    05:21:19
    		 Jupiter closest approach at 42,828 km.
    05:33:52
    		Jupiter shadow exit.
    05:43:03
    		Jupiter occultation exit.
    22:29:00
    		 Amalthea flyby at 127,500 km.
    1975-01-01
    		Phase stop.
    1979-07-31
    		Start Saturn observation phase.
    TimeEvent
    1979-08-29
    		Encounter with Saturnian system.
    06:06:10
    		 Iapetus flyby at 1,032,535 km.
    11:53:33
    		 Phoebe flyby at 13,713,574 km.
    1979-08-31
    12:32:33
    		 Hyperion flyby at 666,153 km.
    1979-09-01
    14:26:56
    		Descending ring plane crossing.
    14:50:55
    		 Epimetheus flyby at 6,676 km.
    15:06:32
    		 Atlas flyby at 45,960 km.
    15:59:30
    		 Dione flyby at 291,556 km.
    16:26:28
    		 Mimas flyby at 104,263 km.
    16:29:34
    		 Saturn closest approach at 20,591 km.
    16:35:00
    		Saturn occultation entry.
    16:35:57
    		Saturn shadow entry.
    16:51:11
    		 Janus flyby at 228,988 km.
    17:53:32
    		Saturn occultation exit.
    17:54:47
    		Saturn shadow exit.
    18:21:59
    		Ascending ring plane crossing.
    18:25:34
    		 Tethys flyby at 329,197 km.
    18:30:14
    		 Enceladus flyby at 222,027 km.
    20:04:13
    		 Calypso flyby at 109,916 km.
    22:15:27
    		 Rhea flyby at 345,303 km.
    1979-09-02
    18:00:33
    		 Titan flyby at 362,962 km.
    1979-10-05
    		Phase stop.
    1979-10-05
    		Begin Pioneer Interstellar Mission.
    1990-
    		Passed the orbit of Pluto.
    1995-09-30
    		Routine daily mission operations stopped. Pioneer 11 is 6.5 billion km from Earth.
    1995-11-24
    		Last signal received.
    [34] [1] [35]

    Current status

    Due to power constraints and the vast distance to the probe, the last routine contact with the spacecraft was on September 30, 1995, and the last good engineering data was received on November 24, 1995. [3] [1]

    As of June 24, 2024, Pioneer 11 is estimated to be 113.121 AU (16.9227 billion km; 10.5153 billion mi) from the Earth and 114.089 AU (17.0675 billion km; 10.6052 billion mi) from the Sun. It was traveling at 11.155 km/s (40,160 km/h; 24,950 mph) relative to the Sun and traveling outward at about 2.35 AU per year. [36] [37] The spacecraft is heading in the direction of the constellation Scutum near the current position (June 2024) RA 18h 54m dec -8° 46' (J2000.0), close to Messier 26. In 928,000 years, it will pass within 0.25 parsecs (0.82 light-years ) of the K dwarf TYC 992-192-1 [38] and will pass near the star Lambda Aquilae in about four million years. [39]

    Pioneer 11 has been overtaken by the two Voyager probes launched in 1977. Voyager 1 has become the most distant object built by humans and will remain so for the foreseeable future, as no probe launched since Voyager has the speed to overtake it. [40]

    Pioneer anomaly

    Analysis of the radio tracking data from the Pioneer 10 and 11 spacecraft at distances between 20 and 70 AU from the Sun had consistently indicated the presence of a small but anomalous Doppler frequency drift. The drift can be interpreted as due to a constant acceleration of (8.74 ± 1.33) × 10−10 m/s2 directed towards the Sun. Although it was suspected that there was a systematic origin to the effect, none was found. As a result, there has been sustained interest in the nature of this so-called "Pioneer anomaly". [41] Extended analysis of mission data by Slava Turyshev and colleagues determined the source of the anomaly to be asymmetric thermal radiation and the resulting thermal recoil force acting on the face of the Pioneers away from the Sun. [42] [43]

    Pioneer plaque

    Pioneer plaque Pioneer10-plaque.jpg
    Pioneer plaque

    Pioneer 10 and 11 both carry a gold-anodized aluminum plaque in the event that either spacecraft is ever found by intelligent lifeforms from other planetary systems. The plaques feature the nude figures of a human male and female along with several symbols that are designed to provide information about the origin of the spacecraft. [44]

    Commemoration

    In 1991, Pioneer 11 was honored on one of 10 United States Postage Service stamps commemorating uncrewed spacecraft exploring each of the then nine planets and the Moon. Pioneer 11 was the spacecraft featured with Jupiter. Pluto was listed as "Not yet explored". [45]

    See also

    Related Research Articles

    <span class="mw-page-title-main">Mariner program</span> NASA space program from 1962 to 1973

    The Mariner program was conducted by the American space agency NASA to explore other planets. Between 1962 and late 1973, NASA's Jet Propulsion Laboratory (JPL) designed and built 10 robotic interplanetary probes named Mariner to explore the inner Solar System – visiting the planets Venus, Mars and Mercury for the first time, and returning to Venus and Mars for additional close observations.

    <span class="mw-page-title-main">Pioneer program</span> Series of United States uncrewed lunar and planetary space probes (1958-60; 1965-92)

    The Pioneer programs were two series of United States lunar and planetary space probes exploration. The first program, which ran from 1958 to 1960, unsuccessfully attempted to send spacecraft to orbit the Moon, successfully sent one spacecraft to fly by the Moon, and successfully sent one spacecraft to investigate interplanetary space between the orbits of Earth and Venus. The second program, which ran from 1965 to 1992, sent four spacecraft to measure interplanetary space weather, two to explore Jupiter and Saturn, and two to explore Venus. The two outer planet probes, Pioneer 10 and Pioneer 11, became the first two of five artificial objects to achieve the escape velocity that will allow them to leave the Solar System, and carried a golden plaque each depicting a man and a woman and information about the origin and the creators of the probes, in case any extraterrestrials find them someday.

    <i>Voyager 1</i> NASA space probe launched in 1977

    Voyager 1 is a space probe launched by NASA on September 5, 1977, as part of the Voyager program to study the outer Solar System and the interstellar space beyond the Sun's heliosphere. It was launched 16 days after its twin, Voyager 2. It communicates through the NASA Deep Space Network (DSN) to receive routine commands and to transmit data to Earth. Real-time distance and velocity data are provided by NASA and JPL. At a distance of 165.2 AU from Earth as of October 2024, it is the most distant human-made object from Earth. The probe made flybys of Jupiter, Saturn, and Saturn's largest moon, Titan. NASA had a choice of either doing a Pluto or Titan flyby; exploration of the moon took priority because it was known to have a substantial atmosphere. Voyager 1 studied the weather, magnetic fields, and rings of the two gas giants and was the first probe to provide detailed images of their moons.

    <i>Voyager 2</i> First spacecraft to visit Uranus and Neptune (launched in 1977 by NASA)

    Voyager 2 is a space probe launched by NASA on August 20, 1977, as a part of the Voyager program. It was launched on a trajectory towards the gas giants Jupiter and Saturn and enabled further encounters with the ice giants Uranus and Neptune. It remains the only spacecraft to have visited either of the ice giant planets, and was the third of five spacecraft to achieve Solar escape velocity, which will allow it to leave the Solar System. It has been sending scientific data to Earth for 47 years, 1 month, 25 days, making it the oldest active space probe. Launched 16 days before its twin Voyager 1, the primary mission of the spacecraft was to study the outer planets and its extended mission is to study interstellar space beyond the Sun's heliosphere.

    <i>Pioneer 10</i> First spacecraft to visit Jupiter and the outer Solar System (1972–2003)

    Pioneer 10 is a NASA space probe launched in 1972 that completed the first mission to the planet Jupiter. Pioneer 10 became the first of five planetary probes and 11 artificial objects to achieve the escape velocity needed to leave the Solar System. This space exploration project was conducted by the NASA Ames Research Center in California. The space probe was manufactured by TRW Inc.

    <span class="mw-page-title-main">Voyager program</span> Ongoing NASA interstellar program

    The Voyager program is an American scientific program that employs two interstellar probes, Voyager 1 and Voyager 2. They were launched in 1977 to take advantage of a favorable alignment of the two gas giants Jupiter and Saturn and the ice giants, Uranus and Neptune, to fly near them while collecting data for transmission back to Earth. After launch, the decision was made to send Voyager 2 near Uranus and Neptune to collect data for transmission back to Earth.

    <i>Cassini–Huygens</i> NASA/ESA mission sent to study Saturn and its moons (1997–2017)

    Cassini–Huygens, commonly called Cassini, was a space-research mission by NASA, the European Space Agency (ESA), and the Italian Space Agency (ASI) to send a space probe to study the planet Saturn and its system, including its rings and natural satellites. The Flagship-class robotic spacecraft comprised both NASA's Cassini space probe and ESA's Huygens lander, which landed on Saturn's largest moon, Titan. Cassini was the fourth space probe to visit Saturn and the first to enter its orbit, where it stayed from 2004 to 2017. The two craft took their names from the astronomers Giovanni Cassini and Christiaan Huygens.

    <span class="mw-page-title-main">Pioneer 4</span> First successful NASA mission to the Moon (1959)

    Pioneer 4 was an American spin-stabilized uncrewed spacecraft launched as part of the Pioneer program on a lunar flyby trajectory and into a heliocentric orbit making it the first probe of the United States to escape from the Earth's gravity. Launched on March 3, 1959, it carried a payload similar to Pioneer 3: a lunar radiation environment experiment using a Geiger–Müller tube detector and a lunar photography experiment. It passed within 58,983 km (36,650 mi) of the Moon's surface. However, Pioneer 4 did not come close enough to trigger its photoelectric sensor. The spacecraft was still in solar orbit as of 1969. It was the only successful lunar probe launched by the U.S. in 12 attempts between 1958 and 1963; only in 1964 would Ranger 7 surpass its success by accomplishing all of its mission objectives.

    <span class="mw-page-title-main">Gravity assist</span> Space navigation technique

    A gravity assist, gravity assist maneuver, swing-by, or generally a gravitational slingshot in orbital mechanics, is a type of spaceflight flyby which makes use of the relative movement and gravity of a planet or other astronomical object to alter the path and speed of a spacecraft, typically to save propellant and reduce expense.

    <i>Sakigake</i> Japanese flyby mission to Halleys Comet (1985–1999)

    Sakigake, known before launch as MS-T5, was Japan's first interplanetary spacecraft, and the first deep space probe to be launched by any country other than the USA or the Soviet Union. It aimed to demonstrate the performance of the new launch vehicle, test its ability to escape from Earth gravity, and observe the interplanetary medium and magnetic field. Sakigake was also supposed to act as a frame of reference for data received from probes that flew closer to Halley's Comet. Early measurements would be used to improve the mission of the Suisei probe launched several months later.

    <i>New Horizons</i> NASA spacecraft launched in 2006

    New Horizons is an interplanetary space probe launched as a part of NASA's New Frontiers program. Engineered by the Johns Hopkins University Applied Physics Laboratory (APL) and the Southwest Research Institute (SwRI), with a team led by Alan Stern, the spacecraft was launched in 2006 with the primary mission to perform a flyby study of the Pluto system in 2015, and a secondary mission to fly by and study one or more other Kuiper belt objects (KBOs) in the decade to follow, which became a mission to 486958 Arrokoth. It is the fifth space probe to achieve the escape velocity needed to leave the Solar System.

    <span class="mw-page-title-main">Grand Tour program</span> NASAs space program intended to explore the outer solar system

    The Grand Tour is a NASA program that would have sent two groups of robotic probes to all the planets of the outer Solar System. It called for four spacecraft, two of which would visit Jupiter, Saturn, and Pluto, while the other two would visit Jupiter, Uranus, and Neptune. The enormous cost of the project, around $1 billion, led to its cancellation and replacement with Mariner Jupiter-Saturn, which became the Voyager program.

    <span class="mw-page-title-main">Exploration of Jupiter</span> Overview of the exploration of Jupiter the planet and its moons

    The exploration of Jupiter has been conducted via close observations by automated spacecraft. It began with the arrival of Pioneer 10 into the Jovian system in 1973, and, as of 2024, has continued with seven further spacecraft missions in the vicinity of Jupiter and two more en route. All but one of these missions were undertaken by the National Aeronautics and Space Administration (NASA), and all but three were flybys taking detailed observations without landing or entering orbit. These probes make Jupiter the most visited of the Solar System's outer planets as all missions to the outer Solar System have used Jupiter flybys. On 5 July 2016, spacecraft Juno arrived and entered the planet's orbit—the second craft ever to do so. Sending a craft to Jupiter is difficult, mostly due to large fuel requirements and the effects of the planet's harsh radiation environment.

    <span class="mw-page-title-main">Exploration of Saturn</span> Overview of the exploration of Saturn

    The exploration of Saturn has been solely performed by crewless probes. Three missions were flybys, which formed an extended foundation of knowledge about the system. The Cassini–Huygens spacecraft, launched in 1997, was in orbit from 2004 to 2017.

    <span class="mw-page-title-main">Planetary flyby</span> Sending a space probe past a planet or dwarf planet

    A planetary flyby is the act of sending a space probe past a planet or a dwarf planet close enough to record scientific data. This is a subset of the overall concept of a flyby in spaceflight.

    <span class="mw-page-title-main">Plasma Wave Subsystem</span> Instrument on board the Voyager space probes

    Plasma Wave Subsystem, abbreviated PWS, is an instrument that is on board the Voyager 1 and Voyager 2 unmanned probes of the Voyager program. The device is 16 channel step frequency receiver and a low-frequency waveform receiver that can measure electron density. The PWS uses the two long antenna in a V-shape on the spacecraft, which are also used by another instrument on the spacecraft. The instrument recorded data about the Solar System's gas giants, and about the outer reaches of the Heliosphere, and beyond. In the 2010s, the PWS was used to play the "sounds of interstellar space" as the spacecraft can sample the local interstellar medium after they departed the Sun's heliosphere. The heliosphere is a region essentially under the influence of the Sun's solar wind, rather than the local interstellar environment, and is another way of understanding the Solar System in comparison to the objects gravitationally bound around Earth's Sun.

    Shensuo, formerly Interstellar Express, is a proposed Chinese National Space Administration program designed to explore the heliosphere and interstellar space. The program will feature two or three space probes that will purportedly be launched in 2024 and follow differing trajectories to encounter Jupiter to assist them out of the Solar System. The first probe, IHP-1, will travel toward the nose of the heliosphere, while the second probe, IHP-2, will fly near to the tail, skimming by Neptune and Triton in January 2038. There may be another probe—tentatively IHP-3—which would launch in 2030 to explore to the northern half of the heliosphere. IHP-1 and IHP-2 would be the sixth and seventh spacecraft to leave the Solar System, as well as first non-NASA probes to achieve this status.

    References

    1. 1 2 3 4 5 6 7 "Pioneer 11 - NASA Science". science.nasa.gov. NASA . Retrieved December 1, 2022.
    2. 1 2 Fimmel, Swindell & Burgess 1974, p. 19.
    3. 1 2 3 "The Pioneer Missions". nasa.gov. NASA / Ames. March 27, 2007. Archived from the original on October 19, 2021. Retrieved March 3, 2015.
    4. ↑ "Milestones of Flight". Smithsonian National Air and Space Museum. Archived from the original on April 15, 2012. Retrieved February 8, 2011.
    5. ↑ Burrows 1990, pp. 266–268.
    6. ↑ Fimmel, Swindell & Burgess 1974, p. 42.
    7. ↑ Mark Wade. "Pioneer 10-11". Encyclopedia Astronautica. Retrieved February 8, 2011.
    8. ↑ "Pioneer 11". Weebau Space Encyclopedia. November 9, 2010. Retrieved January 12, 2012.
    9. ↑ Fimmel, Swindell & Burgess 1974, pp. 42–43.
    10. ↑ Fimmel, Swindell & Burgess 1974, p. 43.
    11. ↑ Fimmel, Swindell & Burgess 1974, pp. 44–45.
    12. ↑ Fimmel, Swindell & Burgess 1974, p. 38.
    13. ↑ "Pioneer 10 & 11". Views of the Solar System. Retrieved December 20, 2018.
    14. ↑ E. J. Smith. "Pioneer 11: Magnetic Fields". nssdc.gsfc.nasa.gov. NASA . Retrieved February 19, 2011.
    15. ↑ A. Barnes. "Pioneer 11: Quadrispherical Plasma Analyzer". nssdc.gsfc.nasa.gov. NASA . Retrieved February 19, 2011.
    16. 1 2 3 4 5 6 7 8 9 10 Simpson 2001, p. 146.
    17. ↑ J. A. Simpson. "Pioneer 11: Charged Particle Instrument (CPI)". nssdc.gsfc.nasa.gov. NASA . Retrieved February 19, 2011.
    18. ↑ F. B. MacDonald. "Pioneer 11: Cosmic-Ray Spectra". nssdc.gsfc.nasa.gov. NASA . Retrieved February 19, 2011.
    19. ↑ J. A. Van Allen. "Pioneer 11: Geiger Tube Telescope (GTT)". nssdc.gsfc.nasa.gov. NASA . Retrieved February 19, 2011.
    20. ↑ R. W. Fillius. "Pioneer 11: Jovian Trapped Radiation". nssdc.gsfc.nasa.gov. NASA . Retrieved February 19, 2011.
    21. ↑ W. H. Kinard. "Pioneer 11: Meteoroid Detectors". nssdc.gsfc.nasa.gov. NASA . Retrieved February 19, 2011.
    22. ↑ R. K. Soberman. "Pioneer 11: Asteroid/Meteoroid Astronomy". nssdc.gsfc.nasa.gov. NASA . Retrieved February 19, 2011.
    23. ↑ D. L. Judge. "Pioneer 11: Ultraviolet Photometry". nssdc.gsfc.nasa.gov. NASA . Retrieved February 19, 2011.
    24. ↑ T. Gehrels. "Pioneer 11: Imaging Photopolarimeter (IPP)". nssdc.gsfc.nasa.gov. NASA . Retrieved February 19, 2011.
    25. ↑ A. P. Ingersoll. "Pioneer 11: Infrared Radiometers". nssdc.gsfc.nasa.gov. NASA . Retrieved February 19, 2011.
    26. ↑ M. H. Acuña. "Pioneer 11: Jovian Magnetic Field". nssdc.gsfc.nasa.gov. NASA . Retrieved September 24, 2013.
    27. ↑ John Uri (September 3, 2019). "40 Years Ago: Pioneer 11 First to Explore Saturn". nasa.gov. NASA . Retrieved July 25, 2024.
    28. ↑ "Pioneer 11 Successfully Retargeted for Saturn". New Scientist . Vol. 62. May 9, 1974. p. 294. Retrieved December 5, 2017.
    29. 1 2 "40 Years Ago: Pioneer 11 First to Explore Saturn - NASA". September 3, 2019. Retrieved October 14, 2024.
    30. ↑ "Pioneer 11 Is Reported to Leave Solar System" . The New York Times . February 25, 1990. p. 24. Retrieved December 3, 2017.
    31. 1 2 "Farewell to a Pioneer". Science News . Vol. 148, no. 16. Society for Science. October 14, 1995. p. 250. JSTOR   4018121.
    32. ↑ D. Savage; Ann Hutchison (September 28, 1995). "Pioneer 11 to End Operations after Epic Career" (TXT). nssdc.gsfc.nasa.gov. NASA / Ames . Retrieved August 7, 2011.
    33. ↑ Elizabeth Howell (September 26, 2012). "Pioneer 11: Up Close with Jupiter & Saturn". Space.com. Retrieved December 10, 2017.
    34. ↑ Fimmel, Swindell & Burgess 1974, pp. 61–94.
    35. ↑ Daniel Muller. "Pioneer 11 Full Mission Timeline". Spaceflight Realtime Simulations and Information. Archived from the original on March 4, 2016. Retrieved January 9, 2011.
    36. ↑ "Spacecraft escaping the Solar System". Heavens Above. Retrieved August 24, 2022.
    37. ↑ "Pioneer 11 - Live Position". www.theskylive.com. Retrieved July 19, 2015.
    38. ↑ C. A. L. Bailer-Jones; D. Farnocchia (April 3, 2019). "Future Stellar Flybys of the Voyager and Pioneer spacecraft". Research Notes of the AAS. 3 (4): 59. arXiv: 1912.03503 . Bibcode:2019RNAAS...3...59B. doi: 10.3847/2515-5172/ab158e . S2CID   134524048.
    39. ↑ "Hardware, Leaving the Solar System: Where are they now?". DK Eyewitness - Encyclopedia of Space and the Universe. 2001. ISBN   978-0-789-40881-5.
    40. ↑ "Voyager - Mission Status". voyager.jpl.nasa.gov. NASA / JPL . Retrieved December 15, 2021.
    41. ↑ Robert Roy Britt (October 18, 2004). "The Problem with Gravity: New Mission Would Probe Strange Puzzle". Space.com. Retrieved June 7, 2011.
    42. ↑ "Pioneer Anomaly Solved!". The Planetary Society . Archived from the original on April 22, 2012. Retrieved April 20, 2012.
    43. ↑ S. G. Turyshev; V. T. Toth; G. Kinsella; et al. (June 12, 2012). "Support for the Thermal Origin of the Pioneer Anomaly". Physical Review Letters . 108 (24): 241101. arXiv: 1204.2507 . Bibcode:2012PhRvL.108x1101T. doi:10.1103/PhysRevLett.108.241101. PMID   23004253.
    44. ↑ C. Sagan; L. S. Sagan; F. Drake (February 25, 1972). "A Message from Earth". Science . 175 (4024): 881–884. Bibcode:1972Sci...175..881S. doi:10.1126/science.175.4024.881. PMID   17781060.
    45. ↑ Syd Kronish (October 27, 1991). "Space Launches are Featured" . The Index Journal. South Carolina, USA. p. 21. Retrieved December 5, 2017– via Newspapers.com.

    Bibliography

    This page is based on this Wikipedia article
    Text is available under the CC BY-SA 4.0 license; additional terms may apply.
    Images, videos and audio are available under their respective licenses.