 Voyager spacecraft |
|
| Organization | NASA |
|---|---|
| Mission type | Flyby |
| Flyby of | Jupiter & Saturn |
| Launch date | September 5, 1977 (32 years, 193 days ago) |
| Launch vehicle | Titan IIIE/Centaur |
| Mission duration | undefined |
| Home page | NASA Voyager website |
| Mass | 721.9 kg (1,592 lb) |
| Power | 420 W |
The Voyager 1 spacecraft is a 722-kilogram (1,592 lb) robotic space probe of the outer Solar System and beyond, launched September 5, 1977. It still receives commands from, and transmits information to Earth, currently pursuing its extended mission to locate and study the boundaries of the Solar System, including the Kuiper belt and beyond. Its original mission was to visit[1] Jupiter and Saturn; and it was the first probe to provide detailed images of the moons of these planets.
Contents |
Voyager 1 is currently the farthest man-made object from Earth, traveling away from both the Earth and the Sun at a speed that corresponds to a greater specific orbital energy than any other probe.[2]
The current speed of New Horizons is slightly greater than Voyager 1 but when New Horizons reaches the same distance from the sun as Voyager 1 is now, its speed will be about 13 km/s (8 miles/sec) compared to Voyager's 17 km/s (10.5 miles/sec).[3] During its flight, Voyager 1 benefited from a number of gravity-assisted speed boosts.
As of August 28, 2009, Voyager 1 was about 110.94 AU (16.596 billion km, or 10.312 billion miles) from the Sun, and has passed the termination shock, entering the heliosheath, with the current goal of reaching and studying the heliopause, which is the known boundary of the solar system.
At this distance, signals from Voyager 1 have a Round Trip Light Time of 30:53:20 (hh:mm:ss) -- versus 24:56:14 for Voyager 2 (as of 2009-09-25).
If Voyager 1 is still functioning when it finally completes the passage through the heliopause (effectively becoming the first human-made object to leave the solar system), scientists will get their first direct measurements of the conditions in the interstellar medium, which may provide clues relevant to the origin and overall nature of the Universe.
With respect to the solar system Voyager 1 is on a hyperbolic trajectory, i.e. its speed (17 km/s) is higher than the local escape velocity. The speed is much less than the escape velocity with respect to the Milky Way (≥ 525 km/s = 326 miles/sec).[4] Thus it will not return to the inner solar system, but stay in the Milky Way.[5][6]
Along with Pioneer 10, Pioneer 11, Voyager 2, and the New Horizons, Voyager 1 is an interstellar probe. If Voyager 1 were traveling in the direction of the nearest star, it would arrive in about 75,000 years.
Voyager 1 had as its primary targets the planets Jupiter and Saturn and their associated moons and rings; its current mission is the detection of the heliopause and particle measurements of solar wind and the interstellar medium.
Both of the Voyager space probes have long outlasted their originally planned lifespan. Each space probe gets its electrical power from three radioisotope thermoelectric generators (RTGs), which are expected to continue to generate enough electric power to let the probes keep communicating with Earth at least until the year 2025.[7]
Voyager 1 was originally planned as Mariner 11 of the Mariner program. From the outset, it was designed to take advantage of the then-new technique of gravity assist. Luckily, the development of interplanetary probes coincided with an alignment of the planets called the Grand Tour.
The Grand Tour was a linked series of gravity assists that, with only the minimal fuel needed for course corrections, would enable a single probe to visit all four of the solar system's gas giant planets: Jupiter, Saturn, Uranus, and Neptune.
The nearly identical Voyager 1 and Voyager 2 space probes were designed with the possibility of a Grand Tour in mind, and their launches were timed to enable the Grand Tour to be carried out if things went well. However, the two Voyagers were only funded by Congress as Jupiter-Saturn probes. At one time, the program was called the "Mariner Jupiter-Saturn" project.
Because of this remarkable planetary alignment, a Voyager-class spacecraft could visit each of the four outer planets mentioned above in just twelve years, instead of the approximately thirty years that would usually be required otherwise.
The Voyager 1 probe was launched on September 5, 1977, by the National Aeronautics and Space Administration from Cape Canaveral, Florida, aboard a Titan IIIE/Centaur carrier rocket, two weeks after its twin space probe, Voyager 2 had been launched on August 20, 1977. Despite being launched after Voyager 2, Voyager 1 was sent off on a somewhat shorter, quicker trajectory, so that it reached both Jupiter and Saturn before its sister space probe did.
For details on the Voyager space probes' identical instrument packages, see the separate article on the overall Voyager Program.
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 kilometres (217,000 miles) 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 11.
 Voyager 1 time lapse movie of Jupiter approach. |
 The Great Red Spot as seen from Voyager 1. |
 Io, the pattern near the bottom of the picture may be a volcanic crater with radiating lava flows. |
 False color detail of Jupiter's atmosphere, as imaged by Voyager 1. |
 Valhalla crater on Callisto. Image taken by Voyager 1 in 1979. |
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.[8]
|
On February 14, 1990, Voyager 1 took the first ever "family portrait" of our solar system as seen from outside,[9] which includes the famous image known as "Pale blue dot". It is estimated that both Voyager crafts have sufficient electrical power to operate their radio transmitters until at least after 2025, which will be over 48 years after launch. Voyager 1 is the most distant functioning space probe to receive commands and transmit information to Earth.
| 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 2008-03-18 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) |
| 2025 or after | Can no longer power any single instrument. |
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.
Scientists at the Johns Hopkins University Applied Physics Laboratory believe that Voyager 1 entered the termination shock in February 2003.[10] Some other scientists have expressed doubt, discussed in the journal Nature of November 6, 2003.[11] 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 with the data from the other instruments on board Voyager I.
However, in May 2005 a NASA press release said that consensus was that Voyager 1 was now in the heliosheath.[12] Scientists anticipate the craft will reach the heliopause in 2015.
Included in the spacecraft is one of the two Voyager Golden Records. This phonograph record contains sounds and images selected to portray the diversity of life and culture on Earth. It is intended for any intelligent extraterrestrial life form, or for future humans, that may find it.
As of 29 January 2010, Voyager 1 was at a distance of 112.816 AU (approximately 16.89 billion kilometers, 10.48 billion miles, or 0.0017 light years) from the Sun, which makes it the most distant human-made object from Earth.[13] At this distance, it is farther away from the Sun than any known natural solar system object, including Eris and 90377 Sedna, but excluding long-period comets. (Although Sedna has a highly-eccentric orbit that takes it 975 AU away from the Sun at aphelion, as of 2006 it is less than 90 AU away from the Sun and approaching its perihelion at 76 AU.[14][15])
At the above distance, light or radio waves, both of which are forms of electromagnetic radiation and propagate at 299,792.5 kilometers per second (the speed of light), take over 14.6 hours to reach the Earth from Voyager 1. As a basis for comparison, the Moon is about 1.4 light-seconds from Earth; the Sun is approximately 8.5 light-minutes away; Pluto is about 5.5 light-hours away; Trans-Neptunian object 2006 SQ372 at aphelion is about 12.3 light-days away; and the nearest star is 4.22 light-years away.
As of 9 October 2009, Voyager 1 was traveling at a speed of 17.078 kilometers per second relative to the Sun (3.6 AU per year or 61,600 km/h or 38,400 miles per hour), about 10% faster than Voyager 2. As of 10 October 2008, Voyager 1 was traveling at a speed of 17.097 kilometers per second relative to the Sun (a reduction of 19 m/s within a single year, due to the attraction of the sun).
On November 19, 2015, Voyager 1 will be 133.15 Astronomical Units from the Sun. Reasonably accurate information concerning its location can be found in this NASA paper with heliocentric coordinates of both space probes extrapolated up to 2015.
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 in the constellation Camelopardalis because AC+79 3888 is moving to the Solar System at about 119 kilometers per second.[16]
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. Its data was checked and verified against data from the Deep Space Network station at Madrid, Spain.[17] This is believed to be the first such tracking of Voyager 1.
As of May 2008, Voyager 1 is at 12.45° declination and 17.125 hours right ascension, placing it in the constellation Ophiuchus as observed from the Earth. NASA continues 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 by measuring the round-trip time delay of radio signals to and from Voyager 1. Then, halving that time delay, and multiplying by the well-known speed of light gives the one-way distance.
 Trajectory of Voyager 1 using Celestia |
 Voyager spacecraft structure |
Media related to Voyager 1 at Wikimedia Commons
|
|||||||||||||||||||||||
|
|||||||||||||||||
 |
The English used in this article or section may not be easy for everybody to understand. You can help Wikipedia by making this page or section simpler. |
The Voyager 1 spacecraft is an 815-kilogram unmanned probe of the outer solar system and beyond, launched September 5, 1977, and is currently operational, making it NASA's longest-lasting mission. It visited Jupiter and Saturn and was the first probe to provide detailed images of the moons of these planets.
Voyager 1 is the farthest human-made object from Earth, traveling away from both the Earth and the Sun at a relatively faster speed than any other probe. The New Horizons mission to Pluto was launched from Earth at a faster speed than Voyager 1, however since that probe will not get all the gravity assists which sped Voyager along its path, it will never pass Voyager 1.[1]
As of August 12, 2006, Voyager 1 is over 14.96 terameters (14.96×109 km, 100 AU or 9.3 billion miles) from the Sun, and has thus entered the heliosheath, the termination shock region between the solar system and interstellar space, a vast area where the Sun's influence gives way to interstellar space. If Voyager 1 is still functioning when it finally passes the heliopause, scientists will get their first direct measurements of the conditions in the interstellar medium. At this distance, signals from Voyager 1 take more than thirteen hours to reach its control center at the Jet Propulsion Laboratory, a joint project of NASA and Caltech near Pasadena, California. Voyager 1 is on a hyperbolic trajectory and has achieved escape velocity, meaning that its orbit will not return to the inner solar system. Along with Pioneer 10, Pioneer 11, and its sister ship Voyager 2, Voyager 1 is an interstellar probe.
Voyager 1 had as its primary targets the planets Jupiter and Saturn and their associated moons and rings; its current mission is the detection of the heliopause and particle measurements of solar wind and the interstellar medium. Both Voyager probes are powered by three radioisotope thermoelectric generators, which have far outlasted their originally intended lifespan, and are now expected to continue to generate enough power to keep communicating with Earth until at least around the year 2020.
Contents |
Voyager 1 was originally planned as Mariner 11 of the Mariner program. From the outset, it was designed to take advantage of the then-new technique of gravity assist. By fortunate chance, the development of interplanetary probes coincided with an alignment of the planets called the Grand Tour. The Grand Tour was a linked series of gravity assists that, with only the minimal fuel needed for course corrections, would enable a single probe to visit all four of the solar system's gas giant planets: Jupiter, Saturn, Uranus and Neptune. The identical Voyager 1 and Voyager 2 probes were designed with the Grand Tour in mind, and their launches were timed to enable the Grand Tour if desired.
Because of this alignment, Voyager could visit each of these planets in just twelve years, instead of the 30 that would usually be required.
Voyager 1 was launched on September 5, 1977 by NASA from Cape Canaveral aboard a Titan IIIE Centaur rocket, shortly after its sister craft, Voyager 2 on August 20, 1977. Despite being launched after Voyager 2, Voyager 1 was sent on a faster trajectory so it reached Jupiter and Saturn before its sister craft.
Initially, an underburn in the second stage of the Titan IIIE rocket left an estimated one second's worth of fuel remaining in that stage. Although ground crews were worried that Voyager 1 would not make it to Jupiter, the Centaur upper stage proved to have enough fuel to compensate.
For details on the Voyager instrument packages, see the separate article on the Voyager program.
Voyager 1 began photographing Jupiter in January 1979. Its closest approach to Jupiter was on March 5, 1979, at a distance of 349,000 kilometers (217,000 miles) from its center. Due to the greater resolution allowed by close approach, most observations of the moons, rings, magnetic fields, and radiation environment of the Jupiter system were made in the 48-hour period bracketing closest approach. It finished photographing the planet in April.
The two Voyager spacecraft made a number of important discoveries about Jupiter and its satellites. The most surprising was the existence of volcanic activity on Io, which had not been observed from the ground or by Pioneer 10 or 11.
Great Red Spot From Voyager
The Great Red Spot as seen from Voyager 1. |
Volcanic crater with radiating lava flows on
Color picture of Io, Jupiter's innermost Galilean satellite. |
Jupiter from Voyager
False color detail of Jupiter's atmosphere, as imaged by Voyager 1. |
Valhalla crater on
Valhalla crater on Callisto. Image taken by Voyager 1 in 1979. |
The gravity assist at Jupiter was successful, and the spacecraft went on to visit Saturn. Voyager 1's Saturn flyby occurred in November 1980, with the closest approach on November 12 when it came within 124,000 kilometers (77,000 miles) of the planet's cloud-tops. The craft detected complex structures in Saturn's rings, and studied the atmospheres of Saturn and Titan. Because of the earlier discovery of a thick atmosphere on Titan, the Voyager controllers at the Jet Propulsion Laboratory elected for Voyager 1 to make a close approach of Titan and terminate its Grand Tour. (For the continuation of the Grand Tour, see the Uranus and Neptune sections of the Voyager 2 article.) The Titan-approach trajectory caused an additional gravity assist that took Voyager 1 out of the plane of the ecliptic, thus ending its planetary science mission.
Titan
Layers of haze covering Saturn's satellite Titan |
Titan's thick haze layer-picture from
Titan's thick haze layer is shown in this enhanced Voyager 1 image. |
It is estimated both Voyager craft would have sufficient electrical power to operate at least some instruments until 2020.
| Year | End of specific capabilities as a result of the available electrical power limitations |
|---|---|
| 2003 | Terminate scan platform and UV observations |
| ~2010 | Termination of gyro operations |
| ~2010 | Termination of DTR operations (limited by ability to capture 1.4 kbit/s data using a 70 m/34 m antenna array) |
| ~2016 | Initiate instrument power sharing |
| > 2020 | Can no longer power any single instrument |
As the Voyager 1 space probe 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.
Scientists at the Johns Hopkins University Applied Physics Lab believe that Voyager entered the termination shock in February 2003. Some other scientists have expressed doubt, discussed in the journal Nature of November 6 2003. In a scientific session at the American Geophysical Union meeting in New Orleans on the morning of March 25 2005, Dr. Ed Stone presented evidence that Voyager 1 crossed the termination shock in December 2004 "SH22A-01". The issue will not be resolved for some months as other data become available, since Voyager's solar-wind detector ceased functioning in 1990. However, in May 2005 a NASA press release said that consensus was that Voyager 1 was now in the heliosheath.[1] Scientists believe the craft will reach the heliopause in 2015.
As of August 12, 2006 at 21:13 UTC (or 07:21:32 UTC without light-time correction), Voyager 1 was at a distance of 100 AU (approximately 14.96 terameters, 9.3 billion miles or 0.002 light years from the Sun), which makes it the most distant human-made object from Earth.[2] At this distance, it is more distant from the Sun than any known natural solar-system object, including 90377 Sedna. Though Sedna has an orbit that takes it 975 AU away from the Sun at apihelion, as of 2006 it is less than 90 AU away from the Sun and approaching its perihelion at 76 AU.
At its current distance, light (which travels at 300,000 kilometers per second) takes over 13.8 hours to reach the spacecraft from Earth. As a basis for comparison, the Moon is about 1.4 light seconds from Earth, the Sun is about 8.5 light minutes away, and Pluto is at an average distance of approximately 5.5 light hours. As of November 2005, the spacecraft was travelling at a speed of 17.2 kilometers per second relative to the sun (3.6 AU per year or 38,400 miles per hour), 10% faster than Voyager 2. Accurate information concerning its location can be found in this NASA paper with heliocentric coordinates extrapolated up to 2015 of both probes. It is not heading towards any particular star, but in 40,000 years it will be within 1.7 light years of the star AC+793888 in the Camelopardis constellation.
Voyager 1, as of September 2006, is at 12.22° declination and 17.051hrs Right Ascension, placing it in the constellation Ophiuchus.
NASA continues daily tracking of Voyager 1 with the Deep Space Network stations.
On 31 March 2006, the amateur radio operators from AMSAT Germany tracked and received data from Voyager 1 using the 20 m dish at Bochum with a long integration technique. Its data were checked and verified against data from the Deep Space Network station at Madrid, Spain. AMSAT-DL article in German; ARRL article in English. This is believed to be the first such tracking of Voyager.
   | NASA ''Voyager'' website - Voyager - The Interstellar Mission |
| | Spacecraft Escaping the Solar System - Spacecraft escaping the Solar System |
| | Voyager Enters Solar System's Final Frontier - NASA - Voyager Enters Solar System's Final Frontier |
| | NASA: Voyager I enters solar system's final frontier - CNN.com - NASA: Voyager I enters solar system's final frontier - May 25, 2005 |
| | ARRL article in English - ARRLWeb: European Hams Hear Signals from the Edge of Space |
| | NASA: Voyager II detects solar system's edge - CNN.com - Voyager II detects solar system's edge - May 23, 2006 |
| | We Are Here: The Pale Blue Dot. - YouTube - We Are Here: The Pale Blue Dot |
| | Spacecraft reaches edge of solar system - CNN.com - Spacecraft reaches edge of solar system - Nov. 5, 2003 |
| | Voyager 1 Mission Profile - Solar System Exploration: Missions: By Target: Beyond Our Solar System: Present: Voyager 1 |
| | NASA's Solar System Exploration - Solar System Exploration |
| | Pioneering NASA Spacecraft Mark Thirty Years of Flight - NASA - Pioneering NASA Spacecraft Mark Thirty Years of Flight |
| | Voyager 1 (NSSDC Master Catalog) - NASA - NSSDC - Spacecraft - Details |
| | this abstract - "SH22A-01" in sm05 |
|
|
Wikis
Quiz
Map
Search
