Voyager 2#Scientific instruments

{{further|Grand Tour program}}

{{Main|Mariner Jupiter-Saturn}}

In the early space age, it was realized that a periodic alignment of the outer planets would occur in the late 1970s and enable a single probe to visit Jupiter, Saturn, Uranus, and Neptune by taking advantage of the then-new technique of gravity assists. NASA began work on a Grand Tour, which evolved into a massive project involving two groups of two probes each, with one group visiting Jupiter, Saturn, and Pluto and the other Jupiter, Uranus, and Neptune. The spacecraft would be designed with redundant systems to ensure survival throughout the entire tour. By 1972 the mission was scaled back and replaced with two Mariner program-derived spacecraft, the Mariner Jupiter-Saturn probes. To keep apparent lifetime program costs low, the mission would include only flybys of Jupiter and Saturn, but keep the Grand Tour option open.{{rp|263}} As the program progressed, the name was changed to Voyager.[https://voyager.jpl.nasa.gov/science/planetary.html Planetary Voyage] {{Webarchive|url=https://web.archive.org/web/20130826105129/http://voyager.jpl.nasa.gov/science/planetary.html |date=August 26, 2013 }} NASA Jet Propulsion Laboratory – California Institute of Technology. March 23, 2004. Retrieved April 8, 2007.

The primary mission of Voyager 1 was to explore Jupiter, Saturn, and Saturn's largest moon, Titan. Voyager 2 was also to explore Jupiter and Saturn, but on a trajectory that would have the option of continuing on to Uranus and Neptune, or being redirected to Titan as a backup for Voyager 1. Upon successful completion of Voyager 1's objectives, Voyager 2 would get a mission extension to send the probe on towards Uranus and Neptune.{{cite book |last1=Butrica |first1=Andrew |title=From Engineering Science to Big Science |page=267 |url=https://history.nasa.gov/SP-4219/Chapter11.html |access-date=September 4, 2015 |quote=Despite the name change, Voyager remained in many ways the Grand Tour concept, though certainly not the Grand Tour (TOPS) spacecraft. |archive-date=February 29, 2020 |archive-url=https://web.archive.org/web/20200229064831/https://history.nasa.gov/SP-4219/Chapter11.html |url-status=live }}

Titan was selected due to the interest developed after the images taken by Pioneer 11 in 1979, which had indicated the atmosphere of the moon was substantial and complex. Hence the trajectory was designed for optimum Titan flyby.{{Cite book |last=David W. Swift |url=https://books.google.com/books?id=E-NGFqfq1LsC&pg=PA69 |title=Voyager Tales: Personal Views of the Grand Tour |date=January 1, 1997 |publisher=AIAA |isbn=978-1-56347-252-7 |page=69}}{{Cite book |last=Jim Bell |url=https://books.google.com/books?id=KXPoAwAAQBAJ&pg=PT93 |title=The Interstellar Age: Inside the Forty-Year Voyager Mission |date=February 24, 2015 |publisher=Penguin Publishing Group |isbn=978-0-698-18615-6 |pages=93}}

Constructed by the Jet Propulsion Laboratory (JPL), Voyager 2, whose bus is shaped like a decagonal prism, included 16 hydrazine thrusters, three-axis stabilization, gyroscopes and celestial referencing instruments (Sun sensor/Canopus Star Tracker) to maintain pointing of the high-gain antenna toward Earth. Collectively these instruments are part of the Attitude and Articulation Control Subsystem (AACS) along with redundant units of most instruments and 8 backup thrusters. The spacecraft also included 11 scientific instruments to study celestial objects as it traveled through space.{{cite web |url=https://starbrite.jpl.nasa.gov/ds-view/pds/viewHostProfile.jsp?INSTRUMENT_HOST_ID=VG2 |title=Voyager 2: Host Information |date=1989 |publisher=NASA |access-date=January 2, 2011 |archive-url=https://web.archive.org/web/20170220172046/https://starbrite.jpl.nasa.gov/ds-view/pds/viewHostProfile.jsp?INSTRUMENT_HOST_ID=VG2 |archive-date=February 20, 2017}}

Built with the intent for eventual interstellar travel, Voyager 2 included a large, {{convert|3.7|m|ft|abbr=on}} parabolic, high-gain antenna (see diagram) to transceive data via the Deep Space Network on Earth. Communications are conducted over the S-band (about 13 cm wavelength) and X-band (about 3.6 cm wavelength) providing data rates as high as 115.2 kilobits per second at the distance of Jupiter, and then ever-decreasing as distance increases, because of the inverse-square law.{{Cite web |last1=Ludwig |first1=Roger |last2=Taylor |first2=Jim |date=2013 |title=Voyager Telecommunications |url=https://voyager.gsfc.nasa.gov/Library/DeepCommo_Chapter3--141029.pdf |url-status=live |access-date=August 7, 2023 |archive-date=August 8, 2023 |archive-url=https://web.archive.org/web/20230808014706/https://voyager.gsfc.nasa.gov/Library/DeepCommo_Chapter3--141029.pdf }} When the spacecraft is unable to communicate with Earth, the Digital Tape Recorder (DTR) can record about 64 megabytes of data for transmission at another time.{{cite web |title=NASA News Press Kit 77–136 |publisher=JPL/NASA |url=http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=9476.0;attach=591860 |access-date=December 15, 2014 |archive-date=May 29, 2019 |archive-url=https://web.archive.org/web/20190529081627/https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=9476.0;attach=591860 |url-status=live }}

File:MHW-RTG.gif

Voyager 2 is equipped with three multihundred-watt radioisotope thermoelectric generators (MHW RTGs). Each RTG includes 24 pressed plutonium oxide spheres. At launch, each RTG provided enough heat to generate approximately 157 W of electrical power. Collectively, the RTGs supplied the spacecraft with 470 watts at launch (halving every 87.7 years). They were predicted to allow operations to continue until at least 2020, and continued to provide power to five scientific instruments through the early part of 2023. In April 2023 JPL began using a reservoir of backup power intended for an onboard safety mechanism. As a result, all five instruments had been expected to continue operation through 2026.{{cite journal |last1=Furlong |first1=Richard R. |last2=Wahlquist |first2=Earl J. |date=1999 |title=U.S. space missions using radioisotope power systems |journal=Nuclear News |volume=42 |issue=4 |pages=26–34 |url=http://www2.ans.org/pubs/magazines/nn/pdfs/1999-4-2.pdf |access-date=January 2, 2011 |archive-date=October 16, 2018 |archive-url=https://web.archive.org/web/20181016011258/http://www3.ans.org/pubs/magazines/nn/pdfs/1999-4-2.pdf |url-status=dead }}{{cite web |title=NASA's Voyager Will Do More Science With New Power Strategy |url=https://www.jpl.nasa.gov/news/nasas-voyager-will-do-more-science-with-new-power-strategy |publisher=NASA Jet Propulsion Laboratory |access-date=April 28, 2023 |archive-date=April 27, 2023 |archive-url=https://web.archive.org/web/20230427182016/https://www.jpl.nasa.gov/news/nasas-voyager-will-do-more-science-with-new-power-strategy |url-status=live }} In October 2024 NASA announced that the plasma science instrument had been turned off, preserving power for the remaining four instruments.{{cite web |url=https://blogs.nasa.gov/voyager/2024/10/01/nasa-turns-off-science-instrument-to-save-voyager-2-power/ | title=NASA Turns Off Science Instrument to Save Voyager 2 Power |date=October 1, 2024 |publisher=NASA}}

Because of the energy required to achieve a Jupiter trajectory boost with an {{convert|825|kg|lb|adj=on}} payload, the spacecraft included a propulsion module made of a {{convert|1123|kg|lb|adj=on}} solid-rocket motor and eight hydrazine monopropellant rocket engines, four providing pitch and yaw attitude control, and four for roll control. The propulsion module was jettisoned shortly after the successful Jupiter burn.

Sixteen hydrazine Aerojet MR-103 thrusters on the mission module provide attitude control.{{cite web |title=MR-103 |url=http://www.astronautix.com/m/mr-103.html |archive-url=https://web.archive.org/web/20161228025700/http://astronautix.com/m/mr-103.html |url-status=dead |archive-date=December 28, 2016 |website=Astronautix.com |access-date=December 11, 2018}} Four are used to execute trajectory correction maneuvers; the others in two redundant six-thruster branches, to stabilize the spacecraft on its three axes. Only one branch of attitude control thrusters is needed at any time.{{cite journal |title=Voyager Backgrounder |url=https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19810001583.pdf#page=21 |website=Nasa.gov |date=October 1980 |publisher=Nasa |access-date=December 11, 2018 |archive-date=June 9, 2019 |archive-url=https://web.archive.org/web/20190609064757/https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19810001583.pdf#page=21 |url-status=live }}

Thrusters are supplied by a single {{convert|70|cm|in|adj=on|sp=us}} diameter spherical titanium tank. It contained {{convert|100|kg|lb}} of hydrazine at launch, providing enough fuel until 2034.{{cite web |last1=Koerner |first1=Brendan |title=What Fuel Does Voyager 1 Use? |url=https://slate.com/news-and-politics/2003/11/what-voyager-1-uses-for-fuel.html |website=Slate.com |access-date=December 11, 2018 |date=November 6, 2003 |archive-date=December 11, 2018 |archive-url=https://web.archive.org/web/20181211192625/https://slate.com/news-and-politics/2003/11/what-voyager-1-uses-for-fuel.html |url-status=live }}

{{Main|Voyager program}}

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• {{small|Data: [https://web.archive.org/web/20030507144627/http://pds-imaging.jpl.nasa.gov/Admin/resources/cd_voyager.html PDS/PDI data catalog], [https://pds-rings.seti.org/voyager/iss/raw_images.html PDS/PRN data catalog]}}

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| {{partial|Radio Science System
{{small|(disabled)}}}}

| (RSS)

| style="text-align:left;" | Utilized the telecommunications system of the Voyager spacecraft to determine the physical properties of planets and satellites (ionospheres, atmospheres, masses, gravity fields, densities) and the amount and size distribution of material in Saturn's rings and the ring dimensions.

• {{small|1=Data: [https://pds-ppi.igpp.ucla.edu/search/?sc=Voyager%202&i=RSS PDS/PPI data catalog], [https://pds-rings.seti.org/voyager/rss/index.html PDS/PRN data catalog] ([https://pds-rings.seti.org/vol/VG_2803_peer_review/ VG_2803]), [https://web.archive.org/web/20111027022734/http://nssdcftp.gsfc.nasa.gov/spacecraft_data/voyager/voyager2/radio_science_rss/ NSSDC Saturn data archive]}}

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| {{partial|Infrared interferometer spectrometer and radiometer
{{small|(disabled)}}}}

| (IRIS)

| style="text-align:left;" | Investigates both global and local energy balance and atmospheric composition. Vertical temperature profiles are also obtained from the planets and satellites as well as the composition, thermal properties, and size of particles in Saturn's rings.

• {{small|Data: [https://pds-rings.seti.org/voyager/iris/original_volume.html PDS/PRN data catalog], [https://pds-rings.seti.org/voyager/iris/expanded_volumes.html PDS/PRN expanded data catalog] ([https://pds-rings.seti.org/vol/VGIRIS_0001_peer_review/ VGIRIS_0001], [https://pds-rings.seti.org/vol/VGIRIS_0002_peer_review/ VGIRIS_002])}}

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| {{partial|Ultraviolet Spectrometer
{{small|(disabled)}}}}

| (UVS)

| style="text-align:left;" | Designed to measure atmospheric properties, and to measure radiation.

• {{small|Data: [https://pds-rings.seti.org/voyager/uvs/data.html PDS/PRN data catalog]}}

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| {{yes|Triaxial Fluxgate Magnetometer
{{small|(active)}}}}

| (MAG)

| style="text-align:left;" | Designed to investigate the magnetic fields of Jupiter and Saturn, the solar-wind interaction with the magnetospheres of these planets, and the interplanetary magnetic field out to the solar wind boundary with the interstellar magnetic field and beyond, if crossed.

• {{small|1=Data: [https://pds-ppi.igpp.ucla.edu/search/?sc=Voyager%202&i=MAG PDS/PPI data catalog], [https://web.archive.org/web/20061010065426/http://nssdcftp.gsfc.nasa.gov/spacecraft_data/voyager/voyager2/magnetic_fields/ NSSDC data archive]}}

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| {{partial|Plasma Spectrometer
{{small|(disabled)}}}}

| (PLS)

| style="text-align:left;" | Investigates the macroscopic properties of the plasma ions and measures electrons in the energy range from 5 eV to 1 keV.

• {{small|1=Data: [https://pds-ppi.igpp.ucla.edu/search/?sc=Voyager%202&i=PLS PDS/PPI data catalog], [https://web.archive.org/web/20061010065406/http://nssdcftp.gsfc.nasa.gov/spacecraft_data/voyager/voyager2/plasma/ NSSDC data archive]}}

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| {{partial|Low Energy Charged Particle Instrument
{{small|(disabled)}}}}

| (LECP)

| style="text-align:left;" | Measures the differential in energy fluxes and angular distributions of ions, electrons and the differential in energy ion composition.

• {{small|1=Data: [https://voyager-mac.umd.edu/ UMD data plotting], [https://pds-ppi.igpp.ucla.edu/search/?sc=Voyager%202&i=LECP PDS/PPI data catalog], [https://web.archive.org/web/20051126100616/http://nssdcftp.gsfc.nasa.gov:80/spacecraft_data/voyager/voyager2/particle/lecp/ NSSDC data archive]}}

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| {{partial|Cosmic Ray System
{{small|(disabled)}}}}

| (CRS)

| style="text-align:left;" | Determines the origin and acceleration process, life history, and dynamic contribution of interstellar cosmic rays, the nucleosynthesis of elements in cosmic-ray sources, the behavior of cosmic rays in the interplanetary medium, and the trapped planetary energetic-particle environment.

• {{small|1=Data: [https://pds-ppi.igpp.ucla.edu/search/?sc=Voyager%202&i=CRS PDS/PPI data catalog], [https://web.archive.org/web/20061009234128/http://nssdcftp.gsfc.nasa.gov/spacecraft_data/voyager/voyager2/particle/crs/ NSSDC data archive]}}

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| {{partial|Planetary Radio Astronomy Investigation
{{small|(disabled)}}}}

| (PRA)

| style="text-align:left;" | Utilizes a sweep-frequency radio receiver to study the radio-emission signals from Jupiter and Saturn.

• {{small|1=Data: [https://pds-ppi.igpp.ucla.edu/search/?sc=Voyager%202&i=PRA PDS/PPI data catalog]}}

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| {{no|Photopolarimeter System
{{small|(defective)}}}}

| (PPS)

| style="text-align:left;" | Utilized a telescope with a polarizer to gather information on surface texture and composition of Jupiter and Saturn and information on atmospheric scattering properties and density for both planets.

• {{small|Data: [https://pds-rings.seti.org/voyager/pps/data.html PDS/PRN data catalog]}}

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| {{yes|Plasma Wave Subsystem
{{small|(active)}}}}

| style="text-align:center" |(PWS)

| style="text-align:left;" | Provides continuous, sheath-independent measurements of the electron-density profiles at Jupiter and Saturn as well as basic information on local wave-particle interaction, useful in studying the magnetospheres.

• {{small|1=Data: [https://pds-ppi.igpp.ucla.edu/search/?sc=Voyager%202&i=PWS PDS/PPI data catalog]}}

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{{Gallery| align = center

| title = Images of the spacecraft |width=175

|File:Voyager Testing 1976 PIA21732.jpg|alt2=Voyager in transport to a solar thermal test chamber | Voyager in transport to a solar thermal test chamber.

|File:Voyager 2 is encapsulated.jpg|alt4=Voyager 2 awaiting payload entry into a Titan IIIE/Centaur rocket | Voyager 2 awaiting payload entry into a Titan IIIE/Centaur rocket.

}}

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| style="vertical-align:top;" | 1981-06-05

| Start Saturn observation phase.

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| style="vertical-align:top;" | 1985-11-04

| Start Uranus observation phase.

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| 1987-08-20

| 10 years of continuous flight and operation at 14:29:00 UTC.

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| style="vertical-align:top;" | 1989-06-05

| Start Neptune observation phase.

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| 1989-10-02

| Begin Voyager Interstellar Mission.

|-

! colspan="2" scope="col" | Interstellar phase[http://www.dmuller.net/spaceflight/mission.php?mission=voyager2&appear=black&showimg=yes "Voyager 2 Full Mission Timeline"] {{Webarchive|url=https://web.archive.org/web/20110723095346/http://www.dmuller.net/spaceflight/mission.php?mission=voyager2&appear=black&showimg=yes |date=July 23, 2011 }} Muller, Daniel, 2010[https://pds-rings.seti.org/voyager/mission/ "Voyager Mission Description"] {{Webarchive|url=https://web.archive.org/web/20181007014859/https://pds-rings.seti.org/voyager/mission/ |date=October 7, 2018 }} NASA, February 19, 1997[https://starbrite.jpl.nasa.gov/ds-view/pds/viewMissionProfile.jsp?MISSION_NAME=VOYAGER "JPL Mission Information"] {{Webarchive|url=https://web.archive.org/web/20170220172041/https://starbrite.jpl.nasa.gov/ds-view/pds/viewMissionProfile.jsp?MISSION_NAME=VOYAGER |date=February 20, 2017 }} NASA, JPL, PDS.

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| 1997-08-20

| 20 years of continuous flight and operation at 14:29:00 UTC.

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| 1998-11-13

| Terminate scan platform and UV observations.

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| 2007-08-20

| 30 years of continuous flight and operation at 14:29:00 UTC.

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| 2007-09-06

| Terminate data tape recorder operations.

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| 2008-02-22

| Terminate planetary radio astronomy experiment operations.

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| 2011-11-07

|Switch to backup thrusters to conserve power{{Cite news |url=https://www.jpl.nasa.gov/news/news.cfm?release=2011-341&rn=news.xml&rst=3189 |title=Voyager 2 to Switch to Backup Thruster Set |date=November 5, 2011 |first=Rosemary |last=Sullivant |id=2011-341 |publisher=JPL |access-date=October 5, 2018 |archive-date=February 26, 2021 |archive-url=https://web.archive.org/web/20210226001915/https://www.jpl.nasa.gov/news/news.cfm?release=2011-341&rn=news.xml&rst=3189 |url-status=dead }}

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| 2017-08-20

| 40 years of continuous flight and operation at 14:29:00 UTC.

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| 2018-11-05

| Crossed the heliopause and entered interstellar space.

|-

| 2023-07-18

| Voyager 2 overtook Pioneer 10 as the second farthest spacecraft from the Sun.{{Cite web|title=Distance between the Sun and Voyager 2|url=https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%27Sun%27&START_TIME=%272023-07-01%27&STOP_TIME=%272023-08-01%27&STEP_SIZE=%271%20day%27&QUANTITIES=%2720%27&CENTER=%27500@-32%27|url-status=live|archive-url=https://web.archive.org/web/20230709162418/https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%27Sun%27&START_TIME=%272023-07-01%27&STOP_TIME=%272023-08-01%27&STEP_SIZE=%271%20day%27&QUANTITIES=%2720%27&CENTER=%27500@-32%27|archive-date=July 9, 2023|access-date=July 18, 2023}}{{Cite web|title=Distance between the Sun and Pioneer 10|url=https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%27Sun%27&START_TIME=%272023-07-01%27&STOP_TIME=%272023-08-01%27&STEP_SIZE=%271%20day%27&QUANTITIES=%2720%27&CENTER=%27500@-23%27|url-status=live|archive-url=https://web.archive.org/web/20230714212211/https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%27Sun%27&START_TIME=%272023-07-01%27&STOP_TIME=%272023-08-01%27&STEP_SIZE=%271%20day%27&QUANTITIES=%2720%27&CENTER=%27500@-23%27|archive-date=July 14, 2023|access-date=July 18, 2023}}

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| 2024-10

| Turned off the plasma science instrument.{{Cite web|url=https://blogs.nasa.gov/voyager/2024/10/01/nasa-turns-off-science-instrument-to-save-voyager-2-power/|title=NASA Turns Off Science Instrument to Save Voyager 2 Power – Voyager|date=October 1, 2024|website=blogs.nasa.gov}}

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| 2025-03-24

| Low-energy charged particle instrument will be turned off.{{Cite web|url=https://www.jpl.nasa.gov/news/nasa-turns-off-two-voyager-science-instruments-to-extend-mission/|title=NASA Turns Off Two Voyager Science Instruments to Extend Mission|website=NASA Jet Propulsion Laboratory (JPL)}}

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{{clear}}

The Voyager 2 probe was launched on August 20, 1977, by NASA from Space Launch Complex 41 at Cape Canaveral, Florida, aboard a Titan IIIE/Centaur launch vehicle. Two weeks later, the twin Voyager 1 probe was launched on September 5, 1977. However, Voyager 1 reached both Jupiter and Saturn sooner, as Voyager 2 had been launched into a longer, more circular trajectory.{{Cite web |url=https://voyager.jpl.nasa.gov/frequently-asked-questions/fact-sheet/ |access-date=June 9, 2024 |website=NASA/JPL |title=Voyager - Fact Sheet |archive-date=April 13, 2020 |archive-url=https://web.archive.org/web/20200413080739/https://voyager.jpl.nasa.gov/frequently-asked-questions/fact-sheet/ |url-status=live }}{{Cite web |url=https://voyager.jpl.nasa.gov/frequently-asked-questions/fast-facts/ |access-date=June 9, 2024 |website=NASA/JPL |title=Voyager - Fast Facts |archive-date=May 22, 2022 |archive-url=https://web.archive.org/web/20220522131332/https://voyager.jpl.nasa.gov/frequently-asked-questions/fast-facts/ |url-status=live }}

Voyager 1{{'}}s initial orbit had an aphelion of {{Convert|8.9|AU|e6mi e9km|abbr=unit}}, just a little short of Saturn's orbit of {{Convert|9.5|AU|e6mi e9km|abbr=unit}}. Whereas, Voyager 2{{'}}s initial orbit had an aphelion of {{Convert|6.2|AU|e6mi e6km|abbr=unit}}, well short of Saturn's orbit.[https://ssd.jpl.nasa.gov/horizons.cgi HORIZONS] {{Webarchive|url=https://web.archive.org/web/20121007034731/https://ssd.jpl.nasa.gov/horizons.cgi |date=October 7, 2012 }}, JPL Solar System Dynamics (Ephemeris Type ELEMENTS; Target Body: Voyager n (spacecraft); Center: Sun (body center); Time Span: launch + 1 month to Jupiter encounter – 1 month)

In April 1978, no commands were transmitted to Voyager 2 for a period of time, causing the spacecraft to switch from its primary radio receiver to its backup receiver.{{cite web |title=40 Years Ago: Voyager 2 Explores Jupiter – NASA |url=https://www.nasa.gov/history/40-years-ago-voyager-2-explores-jupiter/ |access-date=April 4, 2024 |date=July 8, 2019 |archive-date=April 4, 2024 |archive-url=https://web.archive.org/web/20240404165002/https://www.nasa.gov/history/40-years-ago-voyager-2-explores-jupiter/ |url-status=live }} Sometime afterwards, the primary receiver failed altogether. The backup receiver was functional, but a failed capacitor in the receiver meant that it could only receive transmissions that were sent at a precise frequency, and this frequency would be affected by the Earth's rotation (due to the Doppler effect) and the onboard receiver's temperature, among other things.{{cite book |title=Planets Beyond: Discovering the Outer Solar System |last=Littmann |first=Mark |year=2004 |publisher=Courier Corporation |page=106 |url=https://books.google.com/books?id=RoJMadct4TQC&pg=PA106 |isbn=978-0-486-43602-9}}{{cite magazine |last=Davies |first=John |date=January 23, 1986 |title=Voyage to the tilted planet |url= |magazine=New Scientist |page= |pages=39–42 |volume=109 |issue=1492 |id=Google Books [https://www.google.com/books/edition/New_Scientist/sIkoAAAAMAAJ?hl=en&gbpv=1&bsq=%22Voyage%20to%20the%20tilted%20planet%22%20%22Davies%22 sIkoAAAAMAAJ], [https://www.google.com/books/edition/New_Scientist/vdc-AQAAIAAJ?hl=en&gbpv=1&bsq=%22Voyage%20to%20the%20tilted%20planet%22%20%22Davies%22 vdc-AQAAIAAJ]. HathiTrust [https://babel.hathitrust.org/cgi/pt?id=mdp.39015038787464&q1=%22Voyage+to+the+tilted+planet%22&start=1 mdp.39015038787464], [https://babel.hathitrust.org/cgi/pt?id=uc1.31822015726458&q1=%22Voyage+to+the+tilted+planet%22&start=1 uc1.31822015726458].}}

File:Titan 3E Centaur launches Voyager 2.jpg|Voyager 2 launch on August 20, 1977, with a Titan IIIE/Centaur

File:Animation of Voyager 2 trajectory.gif|Animation of Voyager 2{{'s}} trajectory from August 20, 1977, to December 30, 2000
{{legend2|magenta| Voyager 2 }}{{·}}{{legend2|Royalblue|Earth}}{{·}}{{legend2|Lime|Jupiter}} {{·}}{{legend2| Cyan |Saturn}}{{·}}{{legend2| Gold |Uranus }}{{·}}{{legend2| OrangeRed |Neptune }}{{·}}{{legend2| Yellow |Sun }}

File:Voyager 2 path.svg|Trajectory of Voyager 2 primary mission

File:Voyager 2 velocity vs distance from sun.svg|Plot of Voyager 2{{'s}} heliocentric velocity against its distance from the Sun, illustrating the use of gravity assists to accelerate the spacecraft by Jupiter, Saturn and Uranus.{{efn-ua|To observe Triton, Voyager 2 passed over Neptune's north pole, resulting in an acceleration out of the plane of the ecliptic, and, as a result, a reduced velocity relative to the Sun.{{cite web |url=https://solarsystem.nasa.gov/basics/bsf4-1.php |title=Basics of space flight: Interplanetary Trajectories |access-date=October 5, 2018 |archive-date=September 4, 2015 |archive-url=https://web.archive.org/web/20150904150022/https://solarsystem.nasa.gov/basics/bsf4-1.php |url-status=live }}}}

{{Further|Exploration of Jupiter}}

File:Animation of Voyager 2's trajectory around Jupiter.gif

File:Voyager-2 Jupiter-flyby July-10-1979.png

Voyager 2{{'}}s closest approach to Jupiter occurred at 22:29 UT on July 9, 1979. It came within {{convert|570,000|km|mi|abbr=on}} of the planet's cloud tops.{{cite web |url=https://www.jpl.nasa.gov/history/70s/Voyager2_1979.htm |title=History |website=www.jpl.nasa.gov |access-date=October 5, 2018 |archive-date=April 16, 2022 |archive-url=https://web.archive.org/web/20220416064548/https://www.jpl.nasa.gov/history/70s/Voyager2_1979.htm |url-status=dead }}

Jupiter's Great Red Spot was revealed as a complex storm moving in a counterclockwise direction. Other smaller storms and eddies were found throughout the banded clouds.{{Cite web |title=Voyager Mission Description |url=https://pds-rings.seti.org/voyager/mission/#v2_jupiterencounter |access-date=2024-06-22 |website=pdsseti |archive-date=October 7, 2018 |archive-url=https://web.archive.org/web/20181007014859/https://pds-rings.seti.org/voyager/mission/#v2_jupiterencounter |url-status=live }}

Voyager 2 returned images of Jupiter, as well as its moons Amalthea, Io, Callisto, Ganymede, and Europa. During a 10-hour "volcano watch", it confirmed Voyager 1{{'}}s observations of active volcanism on the moon Io, and revealed how the moon's surface had changed in the four months since the previous visit. Together, the Voyagers observed the eruption of nine volcanoes on Io, and there is evidence that other eruptions occurred between the two Voyager fly-bys.

Jupiter's moon Europa displayed a large number of intersecting linear features in the low-resolution photos from Voyager 1. At first, scientists believed the features might be deep cracks, caused by crustal rifting or tectonic processes. Closer high-resolution photos from Voyager 2, however, were puzzling: the features lacked topographic relief, and one scientist said they "might have been painted on with a felt marker". Europa is internally active due to tidal heating at a level about one-tenth that of Io. Europa is thought to have a thin crust (less than {{convert|30|km|mi|abbr=on}} thick) of water ice, possibly floating on a {{Convert|50|km|mi|abbr=unit|adj=on}}-deep ocean.

Two new, small satellites, Adrastea and Metis, were found orbiting just outside the ring. A third new satellite, Thebe, was discovered between the orbits of Amalthea and Io.

{{Gallery| align = center

| style="width:175px;"|File:Jupiter - Region from the Great Red Spot to the South Pole.jpg|alt1=The Great Red Spot photographed during the Voyager 2 flyby of Jupiter | The Great Red Spot photographed during the Voyager 2 flyby of Jupiter

|File:Voyager 2 Jupiter Io.jpg|alt2=A transit of Io across Jupiter, July 9, 1979 | A transit of Io across Jupiter, July 9, 1979

|File:Io - July 10 1979 (34593324401).jpg|alt3=Several faint volcanic eruptions on Io, photographed by Voyager 2 | Several faint volcanic eruptions on Io, photographed by Voyager 2

|File:Crescent Europa - GPN-2000-000469.jpg|alt4=A color mosaic of Europa | A color mosaic of Europa

}}

{{Further|Exploration of Saturn}}

The closest approach to Saturn occurred at 03:24:05 UT on August 26, 1981.{{cite web |url=https://nssdc.gsfc.nasa.gov/nmc/EventQuery.jsp |title=NASA – NSSDCA – Master Catalog – Event Query |website=nssdc.gsfc.nasa.gov |access-date=October 5, 2018 |archive-date=March 26, 2019 |archive-url=https://web.archive.org/web/20190326020912/https://nssdc.gsfc.nasa.gov/nmc/EventQuery.jsp |url-status=live }} When Voyager 2 passed behind Saturn, viewed from Earth, it utilized its radio link to investigate Saturn's upper atmosphere, gathering data on both temperature and pressure. In the highest regions of the atmosphere, where the pressure was measured at {{Convert|70|mbar|psi|abbr=unit}},{{cite web |title=Saturn Approach |url=https://voyager.jpl.nasa.gov/mission/science/saturn/ |publisher=Jet Propulsion Laboratory |access-date=September 8, 2023 |archive-url=https://web.archive.org/web/20230809220343/https://voyager.jpl.nasa.gov/mission/science/saturn/ |archive-date=August 9, 2023 |url-status=live}} Voyager 2 recorded a temperature of {{Convert|82|K|C F|abbr=unit|lk=on}}. Deeper within the atmosphere, where the pressure was recorded to be {{Convert|1200|mbar|psi|abbr=unit}}, the temperature rose to {{Convert|143|K|C F|abbr=unit}}. The spacecraft also observed that the north pole was approximately {{Convert|10|C-change|F-change}} cooler at {{Convert|100|mbar|psi|abbr=unit}} than mid-latitudes, a variance potentially attributable to seasonal shifts (see also Saturn Oppositions).

After its Saturn fly-by, Voyager 2{{'}}s scan platform experienced an anomaly causing its azimuth actuator to seize. This malfunction led to some data loss and posed challenges for the spacecraft's continued mission. The anomaly was traced back to a combination of issues, including a design flaw in the actuator shaft bearing and gear lubrication system, corrosion, and debris build-up. While overuse and depleted lubricant were factors,{{cite journal |last1=Laeser |first1=Richard P. |publisher=Jet Propulsion Laboratory |title=Engineering the voyager uranus mission |journal=Acta Astronautica |year=1987 |volume=16 |pages=75–82 |doi=10.1016/0094-5765(87)90096-8 |url=https://archive.org/details/sim_acta-astronautica_1987_16/page/80/mode/2up |access-date=September 8, 2023 |bibcode=1986inns.iafcQ....L}} other elements, such as dissimilar metal reactions and a lack of relief ports, compounded the problem. Engineers on the ground were able to issue a series of commands, rectifying the issue to a degree that allowed the scan platform to resume its function.{{cite web |author1=Jet Propulsion Laboratory |author1-link=JPL |title=Lesson 394: Voyager Scan Platform Problems |url=https://llis.nasa.gov/lesson/394 |website=NASA Public Lessons Learned System |publisher=NASA |access-date=September 8, 2023 |archive-url=https://web.archive.org/web/20230908075606/https://llis.nasa.gov/lesson/394 |archive-date=September 8, 2023 |date=May 30, 1995 |url-status=live}} Voyager 2, which would have been diverted to perform the Titan flyby if Voyager 1 had been unable to, did not pass near Titan due to the malfunction, and subsequently, proceeded with its mission to explore the Uranian system.{{cite book|author=Bell, Jim|title=The Interstellar Age: Inside the Forty-Year Voyager Mission|url=https://books.google.com/books?id=KXPoAwAAQBAJ&pg=PT93|date=February 24, 2015|publisher=Penguin Publishing Group|isbn=978-0-698-18615-6|page=93|url-status=live|archive-url=https://web.archive.org/web/20160904191620/https://books.google.com/books?id=KXPoAwAAQBAJ&pg=PT93|archive-date=September 4, 2016}}{{rp|94}}

{{Gallery| align = center

| style="width:175px;"

|File:Saturn (planet) large.jpg|alt1=Voyager 2 Saturn approach view | Voyager 2 Saturn approach view

|File:Voyager 2 - Saturn - 3115 7854 2.png|alt2=North, polar region of Saturn imaged in orange and UV filters | North, polar region of Saturn imaged in orange and UV filters

|File:Voyager 2 - Titan - 3128 7866 2.png|alt5=Atmosphere of Titan imaged from 2.3 million km | Atmosphere of Titan imaged from 2.3 million km

|File:Voyager 2 - Titan - 3092 7807 2.png|alt6=Titan occultation of the Sun from 0.9 million km | Titan occultation of the Sun from 0.9 million km

|File:Voyager 2 - Saturn Rings - 3085 7800 2.png|alt8="Spoke" features observed in the rings of Saturn | "Spoke" features observed in the rings of Saturn

}}

{{Further|Exploration of Uranus}}

The closest approach to Uranus occurred on January 24, 1986, when Voyager 2 came within {{convert|81,500|km|mi|sp=us|abbr=unit}} of the planet's cloudtops.[https://voyager.jpl.nasa.gov/mission/science/uranus/ "Uranus Approach"] {{Webarchive|url=https://web.archive.org/web/20180909173736/https://voyager.jpl.nasa.gov/mission/science/uranus/ |date=September 9, 2018 }} NASA Jet Propulsion Laboratory, California Institute of Technology. Accessed December 11, 2018. Voyager 2 also discovered 11 previously unknown moons: Cordelia, Ophelia, Bianca, Cressida, Desdemona, Juliet, Portia, Rosalind, Belinda, Puck and Perdita.{{efn-ua|Some sources cite the discovery of only 10 Uranian moons by Voyager 2, but Perdita was discovered in Voyager 2 images more than a decade after they were taken.{{cite journal |doi=10.1006/icar.2001.6597 |title=Voyager's Eleventh Discovery of a Satellite of Uranus and Photometry and the First Size Measurements of Nine Satellites |journal=Icarus |volume=151 |issue=1 |pages=69–77 |year=2001 |last1=Karkoschka |first1=E. |bibcode=2001Icar..151...69K}}}} The mission also studied the planet's unique atmosphere, caused by its axial tilt of 97.8°; and examined the Uranian ring system. The length of a day on Uranus as measured by Voyager 2 is 17 hours, 14 minutes. Uranus was shown to have a magnetic field that was misaligned with its rotational axis, unlike other planets that had been visited to that point,{{Cite journal |doi=10.1088/0034-4885/56/6/001 |title=Planetary magnetospheres |journal=Reports on Progress in Physics |volume=56 |issue=6 |pages=687–732 |year=1993 |last1=Russell |first1=C. T. |bibcode=1993RPPh...56..687R|s2cid=250897924 }} and a helix-shaped magnetic tail stretching 10 million kilometers (6 million miles) away from the Sun.

When Voyager 2 visited Uranus, much of its cloud features were hidden by a layer of haze; however, false-color and contrast-enhanced images show bands of concentric clouds around its south pole. This area was also found to radiate large amounts of ultraviolet light, a phenomenon that is called "dayglow". The average atmospheric temperature is about {{Convert|60|K|F C|abbr=unit}}. The illuminated and dark poles, and most of the planet, exhibit nearly the same temperatures at the cloud tops.

The Voyager 2 Planetary Radio Astronomy (PRA) experiment observed 140 lightning flashes, or Uranian electrostatic discharges with a frequency of 0.9-40 MHz.{{cite journal |last1=Aplin |first1=K.L. |last2=Fischer |first2=G. |last3=Nordheim |first3=T.A. |last4=Konovalenko | first4=A. |last5=Zakharenko |first5=V. |last6=Zarka |first6= P.|title=Atmospheric Electricity at the Ice Giants |journal=Space Science Reviews |date=2020 |volume=216 |issue=2 |page=26 |doi=10.1007/s11214-020-00647-0 |arxiv=1907.07151 |bibcode=2020SSRv..216...26A }}{{cite journal |last1=Zarka |first1=P. |last2=Pederson |first2=B.M. |title=Radio detection of uranian lightning by Voyager 2 |journal=Nature |date=1986 |volume=323 |issue=6089 |page=605-608 |doi=10.1038/323605a0 |bibcode=1986Natur.323..605Z }} The UEDs were detected from {{cvt|600000|km|mi}} of Uranus over 24 hours, most of which were not visible. However, microphysical modeling suggests that Uranian lightning occurs in convective storms occurring in deep troposphere water clouds. If this is the case, lightning will not be visible due to the thick cloud layers above the troposphere. Uranian lightning has a power of around 10⁸ W, emits 1×10^7 J – 2×10^7 J of energy, and lasts an average of 120 ms.

Detailed images from Voyager 2{{'}}s flyby of the Uranian moon Miranda showed huge canyons made from geological faults.Elizabeth Landau (2016) [https://www.nasa.gov/feature/jpl/voyager-mission-celebrates-30-years-since-uranus "Voyager Mission Celebrates 30 Years Since Uranus"] {{Webarchive|url=https://web.archive.org/web/20170505052650/https://www.nasa.gov/feature/jpl/voyager-mission-celebrates-30-years-since-uranus/ |date=May 5, 2017 }} National Aeronautics and Space Administration, January 22, 2016. Accessed December 11, 2018 One hypothesis suggests that Miranda might consist of a reaggregation of material following an earlier event when Miranda was shattered into pieces by a violent impact.

Voyager 2 discovered two previously unknown Uranian rings.Voyager 2 Mission Team (2012) [https://solarsystem.nasa.gov/news/184/1986-voyager-at-uranus/ "1986: Voyager at Uranus"] {{Webarchive|url=https://web.archive.org/web/20190524214544/https://solarsystem.nasa.gov/news/184/1986-voyager-at-uranus/ |date=May 24, 2019 }} NASA Science: Solar System Exploration, December 14, 2012. Accessed December 11, 2018. Measurements showed that the Uranian rings are different from those at Jupiter and Saturn. The Uranian ring system might be relatively young, and it did not form at the same time that Uranus did. The particles that make up the rings might be the remnants of a moon that was broken up by either a high-velocity impact or torn up by tidal effects.

In March 2020, NASA astronomers reported the detection of a large atmospheric magnetic bubble, also known as a plasmoid, released into outer space from the planet Uranus, after reevaluating old data recorded during the flyby.{{cite news |last=Hatfield |first=Miles |title=Revisiting Decades-Old Voyager 2 Data, Scientists Find One More Secret – Eight and a half years into its grand tour of the solar system, NASA's Voyager 2 spacecraft was ready for another encounter. It was Jan. 24, 1986, and soon it would meet the mysterious seventh planet, icy-cold Uranus. |url=https://www.nasa.gov/feature/goddard/2020/revisiting-decades-old-voyager-2-data-scientists-find-one-more-secret |date=March 25, 2020 |work=NASA |access-date=March 27, 2020 |archive-date=March 27, 2020 |archive-url=https://web.archive.org/web/20200327030510/https://www.nasa.gov/feature/goddard/2020/revisiting-decades-old-voyager-2-data-scientists-find-one-more-secret |url-status=live }}{{cite news |last=Andrews |first=Robin George |title=Uranus Ejected a Giant Plasma Bubble During Voyager 2's Visit – The planet is shedding its atmosphere into the void, a signal that was recorded but overlooked in 1986 when the robotic spacecraft flew past. |url=https://www.nytimes.com/2020/03/27/science/uranus-bubble-voyager.html |date=March 27, 2020 |work=The New York Times |access-date=March 27, 2020 |archive-date=March 27, 2020 |archive-url=https://web.archive.org/web/20200327215013/https://www.nytimes.com/2020/03/27/science/uranus-bubble-voyager.html |url-status=live }}

{{Gallery| align = center

| style="width:175px;"|File:Uranus Voyager2 color calibrated.png|alt1=Uranus as viewed by Voyager 2 | Uranus as viewed by Voyager 2

|File:Uranus Final Image.jpg|alt2=Departing image of crescent Uranus | Departing image of crescent Uranus

|File:Ariel Closest Approach.jpg|alt4=Ariel imaged from 130,000 km | Ariel as imaged from 130,000 km

|File:Uranian rings PIA01977 modest.jpg|alt8=Voyager 2 photo of the Rings of Uranus | The rings of Uranus imaged by Voyager 2

}}

{{Further|Exploration of Neptune}}

Following a course correction in 1987, Voyager 2{{'}}s closest approach to Neptune occurred on August 25, 1989.{{cite news |title=Voyager Steered Toward Neptune |url=https://www.newspapers.com/image/555835 |access-date=December 6, 2017 |work=Ukiah Daily Journal |date=March 15, 1987 |archive-date=December 7, 2017 |archive-url=https://web.archive.org/web/20171207085743/http://www.newspapers.com/image/555835/ |url-status=live }} Through repeated computerized test simulations of trajectories through the Neptunian system conducted in advance, flight controllers determined the best way to route Voyager 2 through the Neptune–Triton system. Since the plane of the orbit of Triton is tilted significantly with respect to the plane of the ecliptic; through course corrections, Voyager 2 was directed into a path about {{Convert|4950|km|mi|abbr=unit}} above the north pole of Neptune.{{cite web |title=Neptune |url=https://voyager.jpl.nasa.gov/science/neptune.html |publisher=Jet Propulsion Laboratory |access-date=March 3, 2016 |archive-date=March 4, 2016 |archive-url=https://web.archive.org/web/20160304090349/http://voyager.jpl.nasa.gov/science/neptune.html |url-status=live }} Five hours after Voyager 2 made its closest approach to Neptune, it performed a close fly-by of Triton, Neptune's largest moon, passing within about {{Convert|40000|km|mi|abbr=unit}}.National Aeronautics and Space Administration [https://voyager.jpl.nasa.gov/mission/science/neptune/ "Neptune Approach"] {{Webarchive|url=https://web.archive.org/web/20180909173736/https://voyager.jpl.nasa.gov/mission/science/neptune/ |date=September 9, 2018 }} NASA Jet Propulsion Laboratory: California Institute of Technology. Accessed December 12, 2018.

In 1989, the Voyager 2 Planetary Radio Astronomy (PRA) experiment observed around 60 lightning flashes, or Neptunian electrostatic discharges emitting energies over 7×10{{sup|8}} J.{{cite journal |last1=Borucki |first1=W.J. |title=Predictions of lightning activity at Neptune |journal=Geophysical Research Letters |date=1989 |volume=16 |issue=8 |page=937-939 |doi=10.1029/gl016i008p00937|bibcode=1989GeoRL..16..937B }} A plasma wave system (PWS) detected 16 electromagnetic wave events with a frequency range of 50 Hz – 12 kHz at magnetic latitudes 7˚–33˚.{{cite journal |title=Whistlers in Neptune's magnetosphere: Evidence of atmospheric lightning |journal=Journal of Geophysical Research: Space Physics |date=1990 |volume=95 |page=20967-20976 |doi=10.1029/ja095ia12p20967|bibcode=1990JGR....9520967G |hdl=2060/19910002329 |hdl-access=free |last1=Gurnett |first1=D. A. |last2=Kurth |first2=W. S. |last3=Cairns |first3=I. H. |last4=Granroth |first4=L. J. |issue=A12 }} These plasma wave detections were possibly triggered by lightning over 20 minutes in the ammonia clouds of the magnetosphere. During Voyager 2{{'}}s closest approach to Neptune, the PWS instrument provided Neptune’s first plasma wave detections at a sample rate of 28,800 samples per second. The measured plasma densities range from 10{{sup|–3}} – 10{{sup|–1}} cm{{sup|–3}}.{{cite journal |last1=Belcher |first1=J.W. |last2=Bridge |first2=H.S. |last3=Bagenal |first3=F. |last4=Coppi |first4=B. |last5=Divers |first5=O. |last6=Eviatar |first6=A. |last7=Gordon |first7=G.S. |last8=Lazarus |first8=A.J. |last9=McNutt |first9=R.L. |last10=Ogilvie |first10= K.W. |last11=Richardson |first11= J.D. |last12= Siscoe |first12=G.L. |last13=Sittler |first13=E.C. |last14=Steinberg |first14=J.T. |last15=Sullivan |first15=J.D. |last16=Szabo |first16=A. |last17=Villanueva |first17=L. |last18=Vasyliunas |first18=V.M. |last19=Zhang |first19=M. |title= Plasma observations near Neptune: Initial results from Voyager 2 |journal=Science |date=1989 |volume=246 |issue=4936 |pages=1478–1483 |doi=10.1126/science.246.4936.1478 |pmid=17756003 |bibcode=1989Sci...246.1478B }}

Voyager 2 discovered previously unknown Neptunian rings,National Aeronautics and Space Administration [https://solarsystem.nasa.gov/moons/neptune-moons/in-depth/ "Neptune Moons"] {{Webarchive|url=https://web.archive.org/web/20200410070225/https://solarsystem.nasa.gov/moons/neptune-moons/in-depth/ |date=April 10, 2020 }} NASA Science: Solar System Exploration. Updated December 6, 2017. Accessed December 12, 2018. and confirmed six new moons: Despina, Galatea, Larissa, Proteus, Naiad and Thalassa.Elizabeth Howell (2016) [https://www.space.com/22222-neptunes-moons.html "Neptune's Moons: 14 Discovered So Far"] {{Webarchive|url=https://web.archive.org/web/20181215172111/https://www.space.com/22222-neptunes-moons.html |date=December 15, 2018 }} Space.com, June 30, 2016. Accessed December 12, 2018.{{efn-ua|One of these moons, Larissa, was first reported in 1981 from ground telescope observations, but not confirmed until the Voyager 2 approach.}} While in the neighborhood of Neptune, Voyager 2 discovered the "Great Dark Spot", which has since disappeared, according to observations by the Hubble Space Telescope.Phil Plait (2016) [https://slate.com/technology/2016/06/hubble-observation-reveals-a-new-dark-spot-on-neptune.html "Neptune Just Got a Little Dark"] {{Webarchive|url=https://web.archive.org/web/20181215175353/https://slate.com/technology/2016/06/hubble-observation-reveals-a-new-dark-spot-on-neptune.html |date=December 15, 2018 }} Slate, June 24, 2016. Accessed December 12, 2018. The Great Dark Spot was later hypothesized to be a region of clear gas, forming a window in the planet's high-altitude methane cloud deck.National Aeronautics and Space Administration (1998) [https://www.jpl.nasa.gov/spaceimages/details.php?id=PIA01286 "Hubble Finds New Dark Spot on Neptune"] {{Webarchive|url=https://web.archive.org/web/20170611173537/https://www.jpl.nasa.gov/spaceimages/details.php?id=PIA01286 |date=June 11, 2017 }} NASA Jet Propulsion Laboratory: California Institute of Technology, August 2, 1998. Accessed December 12, 2018.

{{Gallery| align = center

| style="width:175px;"|File:Neptune Voyager2 color calibrated.png|alt1=Voyager 2 image of Neptune | Voyager 2 image of Neptune

|File:Voyager 2 Neptune and Triton.jpg|alt2=Neptune and Triton three days after Voyager's flyby | Neptune and Triton three days after Voyager 2 flyby

|File:Neptune clouds.jpg|alt7=Cirrus clouds imaged above gaseous Neptune | Cirrus clouds imaged above gaseous Neptune

|File:Rings of Neptune PIA01997.png|alt8=Rings of Neptune taken in occultation from 280,000 km | Rings of Neptune taken in occultation from 280,000 km

|File:Triton moon mosaic Voyager 2 (large).jpg|alt6=Color mosaic of Voyager 2 Triton | Color mosaic of Voyager 2 Triton

}}

File:PIA22924-Voyager2LeavesTheSolarSystem-20181105.jpg

File:Voyager speed and distance from Sun.svg

Once its planetary mission was over, Voyager 2 was described as working on an interstellar mission, which NASA is using to find out what the Solar System is like beyond the heliosphere. {{As of|2023|9}} Voyager 2 is transmitting scientific data at about 160 bits per second.{{cite web |title=Voyager Space Flight Operations Schedule |url=https://voyager.jpl.nasa.gov/pdf/sfos2023pdf/23_09_07-23_09_25.sfos.pdf |website=Voyager Mission Status |publisher=Jet Propulsion Laboratory |access-date=September 8, 2023 |archive-url=https://web.archive.org/web/20230908082427/https://voyager.jpl.nasa.gov/pdf/sfos2023pdf/23_09_07-23_09_25.sfos.pdf |archive-date=September 8, 2023 |date=September 7, 2023 |url-status=live}} Information about continuing telemetry exchanges with Voyager 2 is available from Voyager Weekly Reports.{{cite web |url=https://voyager.jpl.nasa.gov/mission/weekly-reports/index.htm |title=Voyager Weekly Reports |publisher=Voyager.jpl.nasa.gov |date=September 6, 2013 |access-date=September 14, 2013 |archive-date=September 21, 2013 |archive-url=https://web.archive.org/web/20130921055929/http://voyager.jpl.nasa.gov/mission/weekly-reports/index.htm |url-status=live }}

File:72413main ACD97-0036-3.jpg, Pioneer 11, Voyager 1, and Voyager 2 spacecraft.]]

In 1992, Voyager 2 observed the nova V1974 Cygni in the far-ultraviolet, first of its kind. The further increase in the brightness at those wavelengths helped in the more detailed study of the nova.{{Cite report |url=https://quantummechanics.ucsd.edu/ph87/ScientificAmerican/sciam_magnificant-cosmos/nova-of-century.pdf |title=V1974 Cygni 1992: The Most Important Nova of the Century |access-date=June 9, 2024 |archive-date=May 6, 2023 |archive-url=https://web.archive.org/web/20230506063436/https://quantummechanics.ucsd.edu/ph87/ScientificAmerican/sciam_magnificant-cosmos/nova-of-century.pdf |url-status=live }}

In July 1994, an attempt was made to observe the impacts from fragments of the comet Comet Shoemaker–Levy 9 with Jupiter. The craft's position meant it had a direct line of sight to the impacts and observations were made in the ultraviolet and radio spectrum. Voyager 2 failed to detect anything, with calculations showing that the fireballs were just below the craft's limit of detection.{{cite book |last1=Ulivi |first1=Paolo |last2=Harland |first2=David M |date=2007 |title=Robotic Exploration of the Solar System Part I: The Golden Age 1957–1982 |publisher=Springer |page=449 |isbn=978-0-387-49326-8}}

On November 29, 2006, a telemetered command to Voyager 2 was incorrectly decoded by its on-board computer—in a random error—as a command to turn on the electrical heaters of the spacecraft's magnetometer. These heaters remained turned on until December 4, 2006, and during that time, there was a resulting high temperature above {{convert|130|°C|°F|abbr=on}}, significantly higher than the magnetometers were designed to endure, and a sensor rotated away from the correct orientation.{{Cite book|last=Shuai|first=Ping|url=https://books.google.com/books?id=ewcqEAAAQBAJ&pg=PA189|title=Understanding Pulsars and Space Navigations|publisher=Springer Singapore|year=2021|isbn=9789811610677|pages=189|access-date=March 20, 2023|archive-date=April 5, 2023|archive-url=https://web.archive.org/web/20230405145758/https://books.google.com/books?id=ewcqEAAAQBAJ&pg=PA189|url-status=live}}

On August 30, 2007, Voyager 2 passed the termination shock and then entered into the heliosheath, approximately {{Convert|1|e9mi|e9km|abbr=unit}} closer to the Sun than Voyager 1 did.{{cite web |

url=https://www.nasa.gov/mission_pages/voyager/voyager-20071210.html |

title=NASA – Voyager 2 Proves Solar System Is Squashed |

website=www.nasa.gov |

access-date=October 5, 2018 |

archive-date=April 13, 2020 |

archive-url=https://web.archive.org/web/20200413080741/https://www.nasa.gov/mission_pages/voyager/voyager-20071210.html |

url-status=live }} This is due to the interstellar magnetic field of deep space. The southern hemisphere of the Solar System's heliosphere is being pushed in.[https://www.reuters.com/article/scienceNews/idUSN1044867120071211 Voyager 2 finds solar system's shape is 'dented' # 2007-12-10, Week Ending December 14, 2007.] {{Webarchive|url=https://web.archive.org/web/20200927210726/https://www.reuters.com/article/scienceNews/idUSN1044867120071211 |date=September 27, 2020 }} Retrieved December 12, 2007.

On April 22, 2010, Voyager 2 encountered scientific data format problems.{{cite news |url=https://www.boston.com/news/nation/articles/2010/05/06/nasa_working_on_voyager_2_data_problem/ |title=NASA working on Voyager 2 data problem |author=John Antczak |date=May 6, 2010 |agency=Associated Press |access-date=October 5, 2018 |archive-date=March 5, 2016 |archive-url=https://web.archive.org/web/20160305012426/http://www.boston.com/news/nation/articles/2010/05/06/nasa_working_on_voyager_2_data_problem/ |url-status=live }} On May 17, 2010, JPL engineers revealed that a flipped bit in an on-board computer had caused the problem, and scheduled a bit reset for May 19.{{cite web |url=https://www.jpl.nasa.gov/news/news.cfm?release=2010-151 |title=Engineers Diagnosing Voyager 2 Data System |publisher=Jet Propulsion Laboratory |access-date=May 17, 2010 |archive-date=June 12, 2010 |archive-url=https://web.archive.org/web/20100612222643/http://www.jpl.nasa.gov/news/news.cfm?release=2010-151 |url-status=dead }} On May 23, 2010, Voyager 2 resumed sending science data from deep space after engineers fixed the flipped bit.{{cite web |url=http://www.space-travel.com/reports/NASA_Fixes_Bug_On_Voyager_2_999.html |title=NASA Fixes Bug On Voyager 2 |access-date=May 25, 2010 |archive-date=May 27, 2010 |archive-url=https://web.archive.org/web/20100527134927/http://www.space-travel.com/reports/NASA_Fixes_Bug_On_Voyager_2_999.html |url-status=live }}

In 2013, it was originally thought that Voyager 2 would enter interstellar space in two to three years, with its plasma spectrometer providing the first direct measurements of the density and temperature of the interstellar plasma. But the Voyager project scientist, Edward C. Stone and his colleagues said they lacked evidence of what would be the key signature of interstellar space: a shift in the direction of the magnetic field. Finally, in December 2018, Stone announced that Voyager 2 reached interstellar space on November 5, 2018.

File:PIA22921-Voyager2-Position-20181210.jpg: Earth is one astronomical unit (AU) from the Sun; Saturn is at 10 AU, and the heliopause is at around 120 AU. Neptune is 30.1 AU from the Sun; thus the edge of interstellar space is around four times as far from the Sun as the last planet.]]

Maintenance to the Deep Space Network cut outbound contact with the probe for eight months in 2020. Contact was reestablished on November 2, when a series of instructions was transmitted, subsequently executed, and relayed back with a successful communication message.{{Cite news|last=Dockrill|first=Peter|date=November 5, 2020|title=NASA finally makes contact with Voyager 2 after longest radio silence in 30 years|work=Live Science|url=https://www.livescience.com/nasa-makes-contact-voyager-2-long-radio-silence.html|access-date=November 5, 2020|archive-date=November 5, 2020|archive-url=https://web.archive.org/web/20201105133231/https://www.livescience.com/nasa-makes-contact-voyager-2-long-radio-silence.html|url-status=live}} On February 12, 2021, full communications were restored after a major ground station antenna upgrade that took a year to complete.

In October 2020, astronomers reported a significant unexpected increase in density in the space beyond the Solar System as detected by the Voyager 1 and Voyager 2; this implies that "the density gradient is a large-scale feature of the VLISM (very local interstellar medium) in the general direction of the heliospheric nose".{{cite news |last=Starr |first=Michelle |title=Voyager Spacecraft Detect an Increase in The Density of Space Outside The Solar System |url=https://www.sciencealert.com/for-some-reason-the-density-of-space-is-higher-just-outside-the-solar-system |date=October 19, 2020 |work=ScienceAlert |access-date=October 19, 2020 |archive-date=October 19, 2020 |archive-url=https://web.archive.org/web/20201019133221/https://www.sciencealert.com/for-some-reason-the-density-of-space-is-higher-just-outside-the-solar-system |url-status=live }}{{cite journal |last1=Kurth |first1=W.S. |last2=Gurnett |first2=D.A. |title=Observations of a Radial Density Gradient in the Very Local Interstellar Medium by Voyager 2 |date=August 25, 2020 |journal=The Astrophysical Journal Letters |volume=900 |number=1 |pages=L1 |doi=10.3847/2041-8213/abae58 |bibcode=2020ApJ...900L...1K |s2cid=225312823 |doi-access=free }}

On July 18, 2023, Voyager 2 overtook Pioneer 10 as the second farthest spacecraft from the Sun.

On July 21, 2023, a programming error misaligned Voyager 2's high gain antenna{{Cite web |last=Inskeep |first=Steve |date=August 2, 2023 |title=NASA loses contact with Voyager Two after a programming error on Earth |url=https://www.npr.org/2023/08/02/1191519686/nasa-loses-contact-with-voyager-two-after-a-programming-error-on-earth |archive-date=August 2, 2023 |access-date=January 15, 2023 |website=NPR |archive-url=https://web.archive.org/web/20230802093328/https://www.npr.org/2023/08/02/1191519686/nasa-loses-contact-with-voyager-two-after-a-programming-error-on-earth |url-status=live }} 2 degrees away from Earth, breaking communications with the spacecraft. By August 1, the spacecraft's carrier signal was detected using multiple antennas of the Deep Space Network.{{Cite news |date=August 1, 2023 |title=Voyager 2: Nasa picks up 'heartbeat' signal after sending wrong command |language=en-GB |work=BBC News |url=https://www.bbc.com/news/world-66371569 |access-date=August 2, 2023 |archive-date=August 2, 2023 |archive-url=https://web.archive.org/web/20230802095458/https://www.bbc.com/news/world-66371569 |url-status=live }}{{Cite web |date=July 28, 2023 |title=Mission Update: Voyager 2 Communications Pause – The Sun Spot |url=https://blogs.nasa.gov/sunspot/2023/07/28/mission-update-voyager-2-communications-pause/ |access-date=July 29, 2023 |website=blogs.nasa.gov |language=en-US |archive-date=July 29, 2023 |archive-url=https://web.archive.org/web/20230729144934/https://blogs.nasa.gov/sunspot/2023/07/28/mission-update-voyager-2-communications-pause/ |url-status=live }} A high-power "shout" on August 4 sent from the Canberra station{{cite news|author=Ellen Francis|date=August 5, 2023|title='Interstellar shout' restores NASA contact with lost Voyager 2 spacecraft|url=https://www.washingtonpost.com/technology/2023/08/05/nasa-voyager2-contact-interstellar-shout/|newspaper=Washington Post|access-date=August 5, 2023|archive-date=August 5, 2023|archive-url=https://web.archive.org/web/20230805134746/https://www.washingtonpost.com/technology/2023/08/05/nasa-voyager2-contact-interstellar-shout/|url-status=live}} successfully commanded the spacecraft to reorient towards Earth, resuming communications.{{Cite news |date=August 4, 2023 |title=Voyager 2: Nasa fully back in contact with lost space probe |language=en-GB |work=BBC News |url=https://www.bbc.com/news/science-environment-66408851 |access-date=August 4, 2023 |archive-date=August 4, 2023 |archive-url=https://web.archive.org/web/20230804215149/https://www.bbc.com/news/science-environment-66408851 |url-status=live }} As a failsafe measure, the probe is also programmed to autonomously reset its orientation to point towards Earth, which would have occurred by October 15.

As the power from the RTG slowly reduces, various items of equipment have been turned off on the spacecraft.{{Cite web |url=https://voyager.jpl.nasa.gov/mission/science/thirty-year-plan/ |title=Voyager – Operations Plan to the End Mission |website=voyager.jpl.nasa.gov |language=en |access-date=September 20, 2019 |archive-date=September 10, 2020 |archive-url=https://web.archive.org/web/20200910162755/https://voyager.jpl.nasa.gov/mission/science/thirty-year-plan/ |url-status=live }} The first science equipment turned off on Voyager 2 was the PPS in 1991, which saved 1.2 watts.

Some thrusters needed to control the correct attitude of the spacecraft and to point its high-gain antenna in the direction of Earth are out of use due to clogging problems in their hydrazine injector. The spacecraft no longer has backups available for its thruster system and "everything onboard is running on single-string" as acknowledged by Suzanne Dodd, Voyager project manager at JPL, in an interview with Ars Technica.{{cite web | last=Clark | first=Stephen | title=NASA wants the Voyagers to age gracefully, so it's time for a software patch | website=Ars Technica | date=October 24, 2023 | url=https://arstechnica.com/space/2023/10/nasa-wants-the-voyagers-to-age-gracefully-so-its-time-for-a-software-patch/ | access-date=October 27, 2023 | archive-date=October 27, 2023 | archive-url=https://web.archive.org/web/20231027215228/https://arstechnica.com/space/2023/10/nasa-wants-the-voyagers-to-age-gracefully-so-its-time-for-a-software-patch/ | url-status=live }} NASA has decided to patch the computer software in order to modify the functioning of the remaining thrusters to slow down the clogging of the small diameter hydrazine injector jets. Before uploading the software update on the Voyager 1 computer, NASA will first try the procedure with Voyager 2, which is closer to Earth.

The probe is expected to keep transmitting weak radio messages until at least the mid-2020s, more than 48 years after it was launched.{{cite web |url=https://voyager.jpl.nasa.gov/spacecraft/spacecraftlife.html |title=Voyager – Spacecraft – Spacecraft Lifetime |access-date=May 25, 2008 |date=March 15, 2008 |publisher=NASA Jet Propulsion Laboratory |archive-date=March 1, 2017 |archive-url=https://web.archive.org/web/20170301102317/http://voyager.jpl.nasa.gov/spacecraft/spacecraftlife.html |url-status=live }} NASA says that "The Voyagers are destined—perhaps eternally—to wander the Milky Way."{{Cite web |title=Future |url=https://voyager.jpl.nasa.gov/mission/interstellar.html |url-status=live |archive-url=https://web.archive.org/web/20120514175011/http://voyager.jpl.nasa.gov/mission/interstellar.html |archive-date=May 14, 2012 |access-date=October 13, 2013 |publisher=NASA}}

Voyager 2 is not headed toward any particular star. The nearest star is 4.2 light-years away, and at 15.341 km/s, the spacecraft travels one light-year in about 19,541 years - during which time the nearby stars will also move substantially. In roughly 42,000 years, Voyager 2 will pass the star Ross 248 (10.30 light-years away from Earth) at a distance of 1.7 light-years.{{cite journal |title=Future stellar flybys of the Voyager and Pioneer spacecraft |journal=Research Notes of the AAS |volume=3 |issue=4 |pages=59 |date=April 3, 2019 |doi=10.3847/2515-5172/ab158e |last1=Bailer-Jones |first1=Coryn A. L. |last2=Farnocchia |first2=Davide |bibcode=2019RNAAS...3...59B|arxiv=1912.03503 |s2cid=134524048 |doi-access=free }} If undisturbed for 296,000 years, Voyager 2 should pass by the star Sirius (8.6 light-years from Earth) at a distance of 4.3 light-years.{{cite news |last1=Baldwin |first1=Paul |title=NASA's Voyager 2 heads for star Sirius... by time it arrives humans will have died out |url=https://www.express.co.uk/news/world/567957/NASA-s-Voyager-2-sets-course-for-star-Sirius-by-time-it-arrives-human-race-will-be-dead |access-date=September 1, 2022 |work=Express.co.uk |date=December 4, 2017 |language=en |archive-date=September 1, 2022 |archive-url=https://web.archive.org/web/20220901052903/https://www.express.co.uk/news/world/567957/NASA-s-Voyager-2-sets-course-for-star-Sirius-by-time-it-arrives-human-race-will-be-dead |url-status=live }}

{{Main|Voyager Golden Record}}

File:Voyager Golden Record greeting in English.ogg]]

File:The Sounds of Earth Record Cover - GPN-2000-001978.jpg

Both Voyager space probes carry a gold-plated audio-visual disc, a compilation meant to showcase the diversity of life and culture on Earth in the event that either spacecraft is ever found by any extraterrestrial discoverer.{{Cite magazine |last=Ferris |first=Timothy |date=May 2012 |title=Timothy Ferris on Voyagers' Never-Ending Journey |url=https://www.smithsonianmag.com/science-nature/Timothy-Ferris-on-Voyagers-Never-Ending-Journey.html |url-status=dead |archive-url=https://web.archive.org/web/20131104221550/http://www.smithsonianmag.com/science-nature/Timothy-Ferris-on-Voyagers-Never-Ending-Journey.html |archive-date=November 4, 2013 |access-date=August 19, 2013 |magazine=Smithsonian Magazine}}{{Cite web |last=Gambino |first=Megan |title=What Is on Voyager's Golden Record? |url=https://www.smithsonianmag.com/science-nature/what-is-on-voyagers-golden-record-73063839/ |access-date=January 15, 2024 |website=Smithsonian Magazine |language=en |archive-date=April 8, 2020 |archive-url=https://web.archive.org/web/20200408014620/https://www.smithsonianmag.com/science-nature/what-is-on-voyagers-golden-record-73063839/ |url-status=live }} The record, made under the direction of a team including Carl Sagan and Timothy Ferris, includes photos of the Earth and its lifeforms, a range of scientific information, spoken greetings from people such as the Secretary-General of the United Nations and the President of the United States and a medley, "Sounds of Earth", that includes the sounds of whales, a baby crying, waves breaking on a shore, and a collection of music spanning different cultures and eras including works by Wolfgang Amadeus Mozart, Blind Willie Johnson, Chuck Berry and Valya Balkanska. Other Eastern and Western classics are included, as well as performances of indigenous music from around the world. The record also contains greetings in 55 different languages.{{Cite web |title=Voyager Golden record |url=https://voyager.jpl.nasa.gov/spacecraft/goldenrec.html |url-status=live |archive-url=https://web.archive.org/web/20110927062632/http://voyager.jpl.nasa.gov/spacecraft/goldenrec.html/ |archive-date=September 27, 2011 |access-date=August 18, 2013 |publisher=JPL}} The project aimed to portray the richness of life on Earth and stand as a testament to human creativity and the desire to connect with the cosmos.{{Cite magazine |last=Ferris |first=Timothy |date=August 20, 2017 |title=How the Voyager Golden Record Was Made |url=https://www.newyorker.com/tech/annals-of-technology/voyager-golden-record-40th-anniversary-timothy-ferris |access-date=January 15, 2024 |magazine=The New Yorker |language=en-US |issn=0028-792X |archive-date=January 15, 2024 |archive-url=https://web.archive.org/web/20240115000108/https://www.newyorker.com/tech/annals-of-technology/voyager-golden-record-40th-anniversary-timothy-ferris |url-status=live }}

{{Portal|Astronomy|Stars|Spaceflight|Outer space|Solar System}}

• Family Portrait
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{{Reflist|group=upper-alpha}}

{{Reflist}}

• {{cite web |title=Saturn Science Results |website=Voyager Science Results at Saturn |url=https://voyager.jpl.nasa.gov/science/saturn.html |access-date=February 8, 2005}}
• {{cite web |title=Uranus Science Results |website=Voyager Science Results at Uranus |url=https://voyager.jpl.nasa.gov/science/uranus.html |access-date=February 8, 2005}}
• Nardo, Don (2002). Neptune. Thomson Gale. {{ISBN|0-7377-1001-2}}
• [https://descanso.jpl.nasa.gov/DPSummary/Descanso4--Voyager_new.pdf JPL Voyager Telecom Manual]

{{Commons and category}}

• [https://science.nasa.gov/mission/voyager/ NASA Voyager website]
• [https://web.archive.org/web/20070801230949/http://solarsystem.nasa.gov/missions/profile.cfm?MCode=Voyager_2 Voyager 2 Mission Profile] by [https://solarsystem.nasa.gov/ NASA's Solar System Exploration]
• [https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1977-076A Voyager 2 (NSSDC Master Catalog)]

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