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Voyager 1

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This is an old revision of this page, as edited by 110.175.228.227 (talk) at 21:23, 4 October 2012 (Moved explanation of 'termination shock' back to 1st use, since hyperlink erroneously points to heliosphere.). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

This article is about the spacecraft. For the album by The Verve, see Voyager 1 (album). For fictional Voyager One from Space: 1999, see Voyager One (Space: 1999).

Template:Infobox spacecraft

The Voyager 1 spacecraft is a 722 kilogram (1,592 lb) space probe launched by NASA in 1977 to study the outer Solar System and interstellar medium. Operating for 47 years, 1 month and 12 days as of today (17 October 2024) (current operation time), the spacecraft receives routine commands and transmits data back to the Deep Space Network. At a distance of about 122 AU (1.83×1010 km) as of September 2012,[1][2] it is the furthest manmade object from Earth. Voyager 1 is now in the heliosheath, which is the outermost layer of the heliosphere. On June 15, 2012, NASA scientists reported that Voyager 1 may be very close to entering interstellar space and becoming the first manmade object to leave the Solar System.[3][4]

Being a part of the Voyager program with its sister craft Voyager 2, the spacecraft is in extended mission, tasked with locating and studying the boundaries of the Solar System, including the Kuiper belt, the heliosphere and interstellar space. The primary mission ended November 20, 1980, after encountering the Jovian system in 1979 and the Saturnian system in 1980.[5] It was the first probe to provide detailed images of the two largest planets and their moons.

Mission background

History

In the 1960s, a Grand Tour to study the outer planets was proposed. This prompted NASA to begin work on a mission in the early 1970s. The development of the interplanetary probes coincided with a favorable alignment of the planets, which would allow a probe to reach the outer Solar System by means of the then-new gravity assist technique.

Gravity assists would enable a single probe to visit the four gas giants (Jupiter, Saturn, Uranus, and Neptune) while requiring a minimal amount of propellant and a shorter transit duration between planets. Originally, Voyager 1 was planned as Mariner 11 of the Mariner program. Due to budget cuts, the mission was scaled back to be a flyby of Jupiter and Saturn, and renamed the Mariner Jupiter-Saturn probes. As the program progressed, the name was later changed to Voyager as the probe designs began to differ greatly from previous Mariner missions.[6]

Golden record

Voyager Golden Record
Main article: Voyager Golden Record

Each Voyager space probe carries a gold-plated audio-visual disc in the event that either spacecraft is ever found by intelligent life-forms from other planetary systems.[4] The discs carry photos of the Earth and its lifeforms, a range of scientific information, spoken greetings from people (e.g. 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 Earth music, including works by Mozart and Chuck Berry's "Johnny B. Goode".

Spacecraft design

Voyager 1 was constructed by the Jet Propulsion Laboratory. It has 16 hydrazine thrusters, three-axis stabilization gyroscopes, and referencing instruments (Sun sensor/Canopus Star Tracker) to keep the probe's radio antenna pointed 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 travels through space.[7]

Communication system

The radio communication system of Voyager 1 was designed to be used up to and beyond the limits of the solar system during the extremely long flight of this space probe. The communication system includes a 3.7 meter diameter parabolic dish high-gain antenna (see diagram) to send and receive radio waves via the three Deep Space Network stations on the Earth. These modulated waves are placed in the S-band (about 13 cm in wavelength) and X-band (about 3.6 cm in wavelength) which provided a bit rate as high as 115.2 kilobits per second when Voyager 1 was at the distance of Jupiter from the Earth, and many fewer kilobits per second at larger distances.

When Voyager 1 is unable to communicate directly with the Earth, its digital tape recorder (DTR) can record up to 62,500 kilobytes of data for transmission at another time.[7] The length of time needed to send messages to Voyager 1 or to receive messages on the Earth depends on the straight-line distance between the two according to the simple equation t = D/c, where D is the distance and c is the speed of light (about 300,000 km/s). As noted below at the February 8, 2012 entry under Events, the communications signal transit time is over 16 hours.

Power

Voyager 1 has three large radioisotope thermoelectric generators (RTGs). Each RTG contains 24 pressed plutonium-238 oxide spheres. The heat from the spheres generated about 157 watts of electric power at the launch, with the remainder being dissipated as waste heat. Hence there was a total of about 470 watts of electric power provided by the three RTGs.

The power output of the RTGs does decline over time, but the RTGs of Voyager 1 will continue to support some of its operations through about 2025.[7][8]

  • RTG diagram 1
    RTG diagram 1
  • RTG diagram 1
    RTG diagram 1
  • RTG unit
    RTG unit

Scientific instruments

Expand
Instrument Name Abr. Description
Imaging Science System
(disabled) 		(ISS) Utilized a two-camera system (narrow-angle/wide-angle) to provide imagery of Jupiter, Saturn and other objects along the trajectory. More
Filters
Narrow Angle Camera Filters[9]
Name Wavelength Spectrum Sensitivity
Clear 280–640 nm
UV 280–370 nm
Violet 350–450 nm
Blue 430–530 nm
' '
'
Green 530–640 nm
' '
'
Orange 590–640 nm
' '
'
Wide Angle Camera Filters[10]
Name Wavelength Spectrum Sensitivity
Clear 280–640 nm
' '
'
Violet 350–450 nm
Blue 430–530 nm
CH4-U 536–546 nm
Green 530–640 nm
Na-D 588–590 nm
Orange 590–640 nm
CH4-JST 614–624 nm
Radio Science System
(disabled) 		(RSS) 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. More
Infrared Interferometer Spectrometer
(disabled) 		(IRIS) 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. More
Ultraviolet Spectrometer
(active) 		(UVS) Designed to measure atmospheric properties, and to measure radiation. More
Triaxial Fluxgate Magnetometer
(active) 		(MAG) Designed to investigate the magnetic fields of Jupiter and Saturn, the interaction of the solar wind with the magnetospheres of these planets, and the magnetic field of interplanetary space out to the boundary between the solar wind and the magnetic field of interstellar space, if crossed. More
Plasma Spectrometer
(defective) 		(PLS) Investigates the macroscopic properties of the plasma ions and measures electrons in the energy range from 5 eV to 1 keV. More
Low Energy Charged Particle Instrument
(active) 		(LECP) Measures the differential in energy fluxes and angular distributions of ions, electrons and the differential in energy ion composition. More
Cosmic Ray System
(active) 		(CRS) 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. More
Planetary Radio Astronomy Investigation
(disabled) 		(PRA) Utilizes a sweep-frequency radio receiver to study the radio-emission signals from Jupiter and Saturn. More
Photopolarimeter System
(defective) 		(PPS) 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. More
Plasma Wave System
(active) 		(PWS) 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. More

For more details on the Voyager space probes' identical instrument packages, see the separate article on the overall Voyager Program.

Images of the spacecraft
Media related to the Voyager spacecraft at Wikimedia Commons

Mission profile

Timeline of travel
Date Event
1977-09-05 Spacecraft launched at 12:56:00 UTC.
1977-12-10 Entered asteroid belt.
1977-12-19 Voyager 1 overtakes Voyager 2. (see diagram)
1978-09-08 Exited asteroid belt.
1979-01-06 Start Jupiter observation phase.
1980-08-22 Start Saturn observation phase.
1980-12-14 Begin Voyager Interstellar Mission.

[11] [12]

Launch and trajectory

The Voyager 1 probe was launched on September 5, 1977, from Space Launch Complex 41 at Cape Canaveral, Florida, aboard a Titan IIIE-Centaur launch vehicle. The twin Voyager 2 probe had been launched two weeks earlier, on August 20, 1977. Despite being launched later, Voyager 1 reached both Jupiter and Saturn sooner, following a shorter trajectory.

  • Voyager 1 lifted off with a Titan IIIE-Centaur
    Voyager 1 lifted off with a Titan IIIE-Centaur
  • Trajectory of Voyager 1 primary mission
    Trajectory of Voyager 1 primary mission.

Encounter with Jupiter

Main article: Exploration of Jupiter

Voyager 1 began photographing Jupiter in January 1979. Its closest approach to Jupiter was on March 5, 1979, at a distance of about 349,000 kilometers (217,000 mi) from the planet's center. Due to the greater photographic resolution allowed by a closer approach, most observations of the moons, rings, magnetic fields, and the radiation belt environment of the Jovian system were made during the 48-hour period that bracketed the closest approach. Voyager 1 finished photographing the Jovian system in April 1979.

The two Voyager space probes made a number of important discoveries about Jupiter, its satellites, its radiation belts, and its never-before-seen planetary rings. The most surprising discovery in the Jovian system was the existence of volcanic activity on the moon Io, which had not been observed either from the ground, or by Pioneer 10 or Pioneer 11.

  • The Great Red Spot as seen from Voyager 1.
    The Great Red Spot as seen from Voyager 1.
  • False color detail of Jupiter's atmosphere, as imaged by Voyager 1.
    False color detail of Jupiter's atmosphere.
  • View of lava flows radiating from the volcano Ra Patera on Io.
    View of lava flows radiating from the volcano Ra Patera on Io.
  • Volcanic eruption on Io photographed from Voyager 1
    Volcanic eruption on Io photographed from Voyager 1.
Media related to the Voyager 1 Jupiter encounter at Wikimedia Commons

Encounter with Saturn

Main article: Exploration of Saturn

The gravitational assist trajectories at Jupiter were successfully carried out by both Voyagers, and the two spacecraft went on to visit Saturn and its system of moons and rings. Voyager 1's Saturnian flyby occurred in November 1980, with the closest approach on November 12, 1980, when the space probe came within 124,000 kilometers (77,000 mi) of Saturn's cloud-tops. The space probe's cameras detected complex structures in the rings of Saturn, and its remote sensing instruments studied the atmospheres of Saturn and its giant moon Titan.

Because Pioneer 11 had one year earlier detected a thick, gaseous atmosphere over Titan, the Voyager space probes' controllers at the Jet Propulsion Laboratory elected for Voyager 1 to make a close approach of Titan, and of necessity end its Grand Tour there. (For the continuation of the Grand Tour, see the Uranus and Neptune sections of the article on Voyager 2.)

Its trajectory with a close fly-by of Titan caused an extra gravitational deflection that sent Voyager 1 out of the plane of the ecliptic, thus ending its planetary science mission. Voyager 1 could have been commanded onto a different trajectory, whereby the gravitational slingshot effect of Saturn's mass would have steered and boosted Voyager 1 out to a fly-by of Pluto. However, this plutonian option was not exercised, because the other trajectory that led to the close fly-by of Titan was decided to have more scientific value and less risk.[13]

  • View of Saturn lit from the right. Saturn's globe casts its shadow over the rings to the left. Part of the lower hemisphere can be seen through the rings. Some of the spoke-like ring features are visible as bright patches.
    Saturn from 5.3 million km, four days after its closest approach.
  • Mimas at a range of 425,000 km from Voyager 1
    Mimas at a range of 425,000 km from Voyager 1.
  • Tethys photographed by Voyager 1 from 1.2 million km
    Tethys photographed by Voyager 1 from 1.2 million km.
  • Fractured terrain on Dione imaged from a distance of 240,000 km from Voyager 1
    Fractured terrain on Dione.
  • Impact craters on the surface of Rhea appear similar to Earth's Moon
    Impact craters on the surface of Rhea appear similar to Mercury.
  • Cream-colored section of a disk is separated from the black space above by a fuzzy blue curve
    Titan's thick haze layer is shown in this enhanced Voyager 1 image.
  • orange coloured area at bottom right is separated from black space at upper left by diagonal series of blue bands
    Layers of haze covering Saturn's satellite Titan.
  • Voyager 1 image of Saturn's F Ring
    Voyager 1 image of Saturn's F Ring.
Media related to the Voyager 1 Saturn encounter at Wikimedia Commons

Interstellar mission

a set of grey squares trace roughly left to right. A few are labeled with single letters associated with a nearby coloured square. J is near to a square labeled Jupiter; E to Earth; V to Venus; S to Saturn; U to Uranus; N to Neptune. A small spot appears at the centre of each coloured square
The "family portrait" of the Solar System taken by Voyager 1

On February 14, 1990, Voyager 1 took the first ever "family portrait" of our Solar System as seen from outside,[14] which includes the famous image known as "Pale Blue Dot". It is estimated that both Voyager craft have sufficient electrical power to operate their radio transmitters until at least 2025, which will be over 48 years after launch.

On November 17, 1998, Voyager 1 overtook Pioneer 10 as the most distant man-made object from Earth, at a distance of 69.419 AU (1.03849×1010 km). It is currently the most distant functioning space probe to receive commands and transmit information to Earth. The spacecraft's mission now is its eternal mission, to study and wander the interstellar medium. At 17.26 km/s (10.72 mi/s)[15] it has the fastest heliocentric recession speed of any man-made object.[16]

Provided Voyager 1 does not collide with any stellar objects, the New Horizons space probe will never pass it, despite being launched from Earth at a faster speed than either Voyager spacecraft. New Horizons is traveling at about 15 km/s, 2 km/s slower than Voyager 1, and is still slowing down. When New Horizons reaches the same distance from the Sun as Voyager 1 is now, its speed will be about 13 km/s (8 mi/s).[17] The close flyby of Saturn and Titan gave Voyager 1 a massive advantage with its extra gravity assist.

Year End of specific capabilities as a result of the available electrical power limitations
2007 Termination of plasma subsystem (PLS)
2008 Power off Planetary Radio Astronomy Experiment (PRA)
2010 Terminate scan platform and Ultraviolet spectrometer (UVS) observations
2015 Termination of Data Tape Recorder (DTR) operations (limited by ability to capture 1.4 kbit/s data using a 70 m/34 m antenna array. This is the minimum rate at which the DTS can read-out data.)
2016 approx Termination of gyroscopic operations
2020 Start shutdown of science instruments (as of October 18, 2010 the order is undecided but the Low-Energy Charged Particles, Cosmic Ray Subsystem, Magnetometer, and Plasma Wave Subsystem instruments are expected to still be operating)[18]
2025–2030 Can no longer power any single instrument.

Heliopause

As Voyager 1 heads for interstellar space, its instruments continue to study the Solar System; Jet Propulsion Laboratory scientists are using the plasma wave experiments aboard Voyager 1 and 2 to look for the heliopause, the boundary at which the solar wind transitions into the interstellar medium.

a Bow Shock appears to wrap around the heliosphere that encompasses the Solar System
Voyager 1 is currently within the heliosheath and approaching interstellar space.
Plot showing a dramatic increase in the rate of cosmic ray particle detection by theVoyager 1 spacecraft (September 2012).

Scientists at the Johns Hopkins University Applied Physics Laboratory believe that Voyager 1 entered the termination shock in February 2003. [19] This marks the point where the solar wind slows to subsonic speeds. Some other scientists have expressed doubt, discussed in the journal Nature of November 6, 2003.[20] In a scientific session at the American Geophysical Union meeting in New Orleans on the morning of May 25, 2005, Dr. Ed Stone presented evidence that Voyager 1 crossed the termination shock in December 2004.

The issue will not be resolved until other data becomes available, since Voyager 1's solar-wind detector ceased functioning in 1990. This failure has meant that termination shock detection must be inferred from the data from the other instruments on board.[21][22][23]

However, in May 2005 a NASA press release said that consensus was that Voyager 1 was now in the heliosheath.[24] On June 15, 2012, NASA announced that the probe was detecting changes in the environment that are suspected to correlate with arrival at the heliopause.[25]

Current status

Simulated view of the position of Voyager 1 as of February 8, 2012 showing spacecraft trajectory since launch.
yellow spot surrounded by three concentric light-blue ellipses labeled from inside to out: Saturn, Uranus and Neptune. A grey ellipse labeled Pluto overlaps Neptune's ellipse. Four colored lines trails outwards from the central spot: a short red line labeled Voyager 2 traces to the right and up; a green and longer line labeled Pioneer 11 traces to the right; a purple line labeled Voyager 1 traces to the bottom right corner; and a dark blue line labeled Pioneer 10 traces left
Map showing location and trajectories of the Pioneer 10, Pioneer 11, Voyager 1 and Voyager 2 spacecraft, as of April 4, 2007.

Voyager 1 is not heading towards any particular star, but in about 40,000 years it will pass within 1.6 light years of the star AC+79 3888, which is at present in the constellation Camelopardalis. That star is generally moving towards our Solar System at about 119 km/s (430,000 km/h; 270,000 mph).[26]

On February 17, 1998, Voyager 1 became the furthest man-made object from Earth, passing Pioneer 10 at 69 AU from the Sun.[27] From this day onwards to the present, Voyager 1 has been the farthest manmade object from Earth, and no probe has passed its distance and there are no probes predicted to be launched in the next 20 years that will pass the probe.[citation needed]

On December 18, 2004, Voyager 1 passed the termination shock.[citation needed] This is the unofficial date of departure from the Solar System.[citation needed] While the spacecraft still remains under the Sun's influence, at the termination shock particles from the interstellar medium interact with solar particles, signaling that the hypothetical heliopause is not far from this point. Six years later in 2010 Voyager 1 entered an area of the heliosheath where the solar wind outward speed is 0, or flowing sideways relative to the Sun. This signals that Voyager 1 is getting very close to entering the interstellar medium.

On March 31, 2006, the amateur radio operators from AMSAT in Germany tracked and received radio waves from Voyager 1 using the 20-meter (66 ft) dish at Bochum with a long integration technique. Retrieved data was checked and verified against data from the Deep Space Network station at Madrid, Spain.[28] This is believed to be the first such tracking of Voyager 1.

On December 13, 2010, it was confirmed that Voyager 1 passed the reach of the solar wind emanating from the Sun. It is suspected that solar wind at this distance turns sideways due to interstellar wind pushing against the heliosphere. Since June 2010, detection of solar wind has been consistently at zero, providing conclusive evidence of the event.[29] The meridional (north-south) speed of the solar wind, which is suspected to have increased, cannot be inferred in Voyager 1's current configuration.[citation needed] On this date, the spacecraft was approximately 17.3 billion kilometers (116 AU or 10.8 billion miles) from the Sun.[30]

On March 8, 2011, Voyager 1 was commanded to change its orientation to detect the current direction of the solar wind. A test roll done in February confirmed the spacecraft's ability to maneuver and reorient itself. The course of the spacecraft was not changed. It rotated 70 degrees counterclockwise with respect to Earth to detect the solar wind. This was the first time the spacecraft had done any major maneuvering since the family portrait photograph of the planets was taken in 1990. The spacecraft will be maneuvered again in the coming months to further analyze the solar wind. After the first roll the spacecraft had no problem in reorienting itself with Alpha Centauri, Voyager 1's guide star, and it resumed sending transmissions back to Earth. This is a major milestone in the Voyager interstellar program. Voyager 2 is still detecting outward flow of solar wind but it is estimated that in the coming months or years it will experience the same conditions as Voyager 1.[31][32]

On May 21, 2011, the spacecraft was reported at 12.44° declination and 17.163 hours right ascension, and at an ecliptic latitude of 34.9° (the ecliptic latitude changes very slowly), placing it in the constellation Ophiuchus as observed from the Earth.[13] NASA continued its daily tracking of Voyager 1 with its Deep Space Network. This network measures both the elevation and azimuth angles of the incoming radio waves from Voyager 1, and it also measures the distance from the Earth to Voyager 1.

On June 15, 2011, the distance to the interstellar medium was recalculated, which is now believed to be much less than previously thought. NASA believes that Voyager 1 may cross into the space between the stars sometime in the next year or so. The Low Energy Charged Particle device on Voyager 1 has detected the outward flow of the solar wind to be at zero. This means it is flowing parallel up and down to the Sun, signaling that the interstellar medium is very close. Voyager 2 still has more travel time before it reaches the interstellar medium, while scientists believed Voyager 1 will enter interstellar space "at any time".[33]

On December 1, 2011, it was announced that Voyager 1 detected the first Lyman-alpha radiation originating from the Milky Way galaxy. Lyman-alpha radiation had previously been detected from other galaxies, but due to interference from the Sun, the radiation from the Milky Way was not detectable.[34]

On December 5, 2011, it was announced that Voyager 1 had entered a new region referred to as a "cosmic purgatory" by NASA. Within this stagnation region, charged particles streaming from the Sun slow and turn inward, and the solar system's magnetic field has doubled in strength as interstellar space appears to be applying pressure. Energetic particles originating in the solar system have declined by nearly half, while the detection of high-energy electrons from outside has increased by 100 fold. The inner edge of the stagnation region is located approximately 113 astronomical units from the Sun, while the outer edge is unknown.[35][36]

On June 14, 2012, NASA announced that Voyager 1 has reported a marked increase in its detection of charged particles from interstellar space, which are normally deflected by the solar winds within the heliosphere from the Sun. The craft thus begins to enter the interstellar medium at the "final frontier of the solar system",[37][24] or the "edge of the Solar System"[38][39]. Voyager 1 is the farthest man-made object from Earth.

On September 5, 2012, Voyager 1 was in space for 35 years since its launch to Jupiter and Saturn. The craft is currently more than 11 billion miles from the sun. Twin Voyager 2, which celebrated its launch anniversary two weeks earlier, trails behind at 9 billion miles from the sun.[40]

On September 9, 2012, Voyager 1 was 121.836 AU (1.82264×1010 km; 1.13254×1010 mi) from the Earth and 121.798 AU (1.82207×1010 km; 1.13218×1010 mi) from the Sun; and traveling at 17.043 km/s (38,120 mph) (relative to the Sun) and traveling outward at about 3.595 AU per year.[1] Sunlight takes 16.89 hours to get to Voyager 1. The brightness of the Sun from the spacecraft is magnitude −16.3.[1] Voyager 1 is heading in the direction of the constellation Ophiuchus.[1] (To compare, Proxima Centauri, the closest star to our Sun, is about 4.2 light-years (or 2.65×105 AU) distant. Voyager 1's current relative velocity to the Sun is 17,043 m/s (61,350 km/h; 38,120 mph). This calculates as 3.592 AU per year, about 10% faster than Voyager 2. At this velocity, 73,775 years would pass before reaching the nearest star, Proxima Centauri, were the spacecraft traveling in the direction of that star. Voyager 1 will need about 17,565 years at its current velocity to travel a complete light year.)

Voyager 1 is predicted to enter the interstellar medium between 2012–15.

See also

References

  1. ^ a b c d Peat, Chris (September 9, 2012). "Spacecraft escaping the Solar System". Heavens-Above. Retrieved September 9. 2012. {{cite web}}: Check date values in: |accessdate= (help)
  2. ^ Voyager 1, Where are the Voyagers – NASA Voyager 1
  3. ^ Amos, Jonathan (June 15, 2012). "Particles point way for Nasa's Voyager". BBC News. Retrieved June 15, 2012.
  4. ^ a b Ferris, Timothy (May 2012). "Timothy Ferris on Voyagers' Never-Ending Journey". Smithsonian Magazine. Retrieved June 15, 2012.
  5. ^ The term "visit" is used here in the sense of "approach".
  6. ^ Chapter 11 "Voyager: The Grand Tour of Big Science" (sec. 268.), by Andrew,J. Butrica, found in From Engineering Science To Big Science ISBN 978-0-16-049640-0 edited by Pamela E. Mack, NASA, 1998
  7. ^ a b c "VOYAGER 1:Host Information". NASA. 1989. Retrieved January 2, 2011.
  8. ^ Furlong, Richard R.; Wahlquist, Earl J. (1999). "U.S. space missions using radioisotope power systems" (PDF). Nuclear News. 42 (4): 26–34. Retrieved January 2, 2011.
  9. ^ "Voyager 1 Narrow Angle Camera Description". NASA / PDS. August 26, 2003. Retrieved January 17, 2011. {{cite web}}: |first= missing |last= (help)
  10. ^ "Voyager 1 Wide Angle Camera Description". NASA / PDS. August 26, 2003. Retrieved January 17, 2011. {{cite web}}: |first= missing |last= (help)
  11. ^ "Voyager Mission Description" NASA, February 19, 1997
  12. ^ "Voyager 1 Full Mission Timeline" Muller, Daniel, 2010
  13. ^ a b "Voyager – Frequently Asked Questions". Voyager.jpl.nasa.gov. February 14, 1990. Retrieved September 1, 2010.
  14. ^ "Photo Capion". Public Information Office. Retrieved August 26, 2010.
  15. ^ Webb, Stephen (2002). If the universe is teeming with aliens-- where is everybody?: fifty solutions to the Fermi paradox and the problem of extraterrestrial life. Copernicus Series. Springer. p. 62. ISBN 0-387-95501-1.
  16. ^ Darling, Dr. David. "Fastest Spacecraft". Retrieved February 4, 2012.
  17. ^ "New Horizons Salutes Voyager". New Horizons. August 17, 2006. Retrieved November 3, 2009.
  18. ^ "Voyager – Spacecraft – Spacecraft Lifetime". NASA Jet Propulsion Laboratory. October 18, 2010. Retrieved September 30, 2011. shutdown order has not been determined
  19. ^ Tobin, Kate (November 5, 2003). "Spacecraft reaches edge of solar system". CNN. Retrieved August 7, 2007.
  20. ^ L A Fisk (2003). "Planetary Science: Over the edge?". Nature. 426 (6962): 21–22. doi:10.1038/426021a. PMID 14603294.
  21. ^ Stamatios M. Krimigis (2003). "Voyager 1 exited the solar wind at a distance of 85 au from the Sun". Nature. 426: 45–48. doi:10.1038/nature02068. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  22. ^ Frank B. McDonald (2003). "Enhancements of energetic particles near the heliospheric termination shock". Nature. 426: 48–51. doi:10.1038/nature02066. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  23. ^ Leonard F. Burlaga (2003). "Search for the heliosheath with Voyager 1 magnetic field measurements". Geophysical Research Letters. 30: 2072–2075. Bibcode:2003GeoRL..30tSSC9B. doi:10.1029/2003GL018291. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  24. ^ a b "Voyager Enters Solar System's Final Frontier". NASA. May 24, 2005. Retrieved August 7, 2007.
  25. ^ NASA Voyager 1 Spacecraft Nears Interstellar Space
  26. ^ "Voyager – Mission – Interstellar Mission". Voyager.jpl.nasa.gov. August 9, 2010. Retrieved March 17, 2011.
  27. ^ "Voyager 1 now most distant man-made object in space". CNN. February 17, 1998. Archived from the original on July 1, 2012. Retrieved July 1, 2012.
  28. ^ AMSAT-DL article in German; ARRL article in English
  29. ^ Voyager 1 Sees Solar Wind Decline
  30. ^ Jonathan Amos (December 14, 2010). "Voyager near Solar System's edge". BBC News. Retrieved December 21, 2010.
  31. ^ Voyager – The Interstellar Mission
  32. ^ "Voyager: Still dancing 17 billion km from Earth". BBC News. March 9, 2011.
  33. ^ NASA/Jet Propulsion Laboratory (June 15, 2011). Recalculating the distance to interstellar space. ScienceDaily
  34. ^ "Voyager Probes Detect "invisible" Milky Way Glow". National Geographic. December 1, 2011. Retrieved December 4, 2011.
  35. ^ "Spacecraft enters 'cosmic purgatory'". December 6, 2011. Retrieved December 7, 2011.
  36. ^ "Voyager 1 hits new region at solar system edge". December 5, 2011. Retrieved December 7, 2011.
  37. ^ ""Did You Know"? – Voyager – The Interstellar Mission". NASA. Retrieved September 5, 2012.
  38. ^ "What Does the Edge of the Solar System Look Like? Ask Voyager". NASA. November 5, 2003. Retrieved September 5, 2012.
  39. ^ "Data From NASA's Voyager 1 Point to Interstellar Future". June 14, 2012. Retrieved June 16, 2012. {{cite web}}: Unknown parameter |publishser= ignored (|publisher= suggested) (help)
  40. ^ "NASA's Voyager 1 on verge of leaving solar system". CBS News. Retrieved September 4, 2012.

Media related to Voyager 1 at Wikimedia Commons

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