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How fast are the Voyager spacecrafts travelling?

NASA's Voyage probes are speeding their way around the Solar System.

Keiron Allen

Asked by: Anonymous

Launched in 1977, NASA’s two Voyager probes surveyed Jupiter and Saturn, with Voyager 2 also visiting Uranus and Neptune before heading out of the Solar System. Voyager 1 has since become the fastest and most distant man-made object in the Universe, travelling at around 61,500km/h at a distance of 17.6 billion km from the Earth. Perhaps most incredible of all, NASA is still in communication with it, despite radio signals taking 16 hours to reach it.

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We Finally Know What Happened When Voyager 2 Reached Interstellar Space

A few big takeaways from the craft's incredible journey.

• Scientists have finally analyzed data from Voyager 2’s journey to interstellar space and discovered remarkable insight into conditions at the edge of our solar system .
• The spacecraft reached the interstellar boundary between our solar system and interstellar space in 2018. Voyager 1 reached the boundary in 2012.
• Both spacecraft were launched in 1977, and have far surpassed scientists' expectations.

Scientists have finally analyzed data from Voyager 2’s journey to interstellar space and discovered a number of surprising differences—plus a few strange similarities.

Voyager 1 and 2 launched in August and October of 1977, respectively, and set out to explore the far reaches of the solar system and beyond. The spacecraft have revealed a vast amount of insight into distant planets and snapped pictures of previously undiscovered moons. Still, more than 40 years after their launch, they continue to provide scientists with an unparalleled look at the universe.

In 2012, Voyager 1 became the first spacecraft to reach interstellar space. Last year, Voyager 2 joined its companion in the interstellar medium, reaching the boundary set 119 times the Earth–sun distance away from Earth. The transition from our solar system to interstellar space, the researchers say, may take less than a day to cross. The data from Voyager 2’s crossing was published November 4 in a series of five papers in Nature Astronomy .

The heliopause is the theoretical boundary at which the sun’s solar wind meets interstellar winds, which are shot out from supernovae that have exploded millions of years ago. Additionally, galactic cosmic rays try to flow into our solar system, but only 30 percent of these rays actually reach Earth. Voyager 1 and 2 were also able to study changes in the magnetic fields within and outside of our solar system.

The two spacecraft reached interstellar space during different periods of solar activity, meaning conditions along the boundary were markedly different. Voyager 1 reached the interstellar boundary during the sun’s solar minimum, whereas Voyager 2 reached the boundary during the solar maximum, a period of heightened activity. Additionally, unlike its quicker counterpart, Voyager 2’s mission has largely taken place in Earth’s southern hemisphere.

The researchers also discovered that solar material was “leaking” out into the interstellar medium. “That was very different than what happened with Voyager 1, where hardly any material was leaking out,” said Tom Krimigis of John’s Hopkins’s Applied Physics Laboratory in an October 31 press conference.

In the case of Voyager 1, the team saw the opposite, where interstellar particles leaked into our solar system. The team hopes to reconvene to take a closer look at their data in the near future to understand how and why these particles slip out of the grasp of our solar system.

Another perplexing discovery? The direction of the magnetic fields both inside and outside of the heliopause is aligned, as was the case with Voyager 1. Leonard Burlaga of NASA Goddard Space Flight Center said scientists can dismiss the alignment of the magnetic fields once, but twice would be a remarkable coincidence. The strength of the magnetic field was stronger in interstellar space, the Voyager 2 found.

The scientists also discovered that the heliopause itself is much thinner and smoother than expected, and that the interstellar medium tucked close to the boundary layer, where solar and interstellar winds meet, is much hotter and unpredictable than expected. This newest research also revealed that the boundary layer itself may be more complex than initially thought, with multiple layers of different temperature, density, and speed.

Voyager 1 and 2 have roughly five years before they'll lose the use of their scientific instruments, said Ed Stone of the California Institute of Technology during the press conference. "When the two voyagers were launched, the space age was only 20 years old, Stone said. "So it was hard to know at that time that anything could last over 40 years."

There's still a lot left to explore, and the data dump has sparked a desire to explore faster, farther, and deeper into interstellar space.

Jennifer Leman is a science journalist and senior features editor at Popular Mechanics, Runner's World, and Bicycling. A graduate of the Science Communication Program at UC Santa Cruz, her work has appeared in The Atlantic, Scientific American, Science News and Nature. Her favorite stories illuminate Earth's many wonders and hazards.

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Two Voyager Spacecraft Still Going Strong After 20 Years 

Twenty years after their launch and long after their planetary reconnaissance flybys were completed, both Voyager spacecraft are now gaining on another milestone -- crossing that invisible boundary that separates our solar system from interstellar space, the heliopause.

Since 1989, when Voyager 2 encountered Neptune, both spacecraft have been studying the environment of space in the outer solar system. Science instruments on both spacecraft are sensing signals that scientists believe are coming from the heliopause -- the outer most edge of the Sun's magnetic field that the spacecraft must pass through before they reach interstellar space.

"During their first two decades the Voyager spacecraft have had an unequaled journey of discovery. Today, even though Voyager 1 is now more than twice as far from the Sun as Neptune, their journey is only half over and more unique opportunities for discovery await the spacecraft as they head toward interstellar space," said Dr. Edward Stone, Voyager project scientist and director of NASA's Jet Propulsion Laboratory, Pasadena, CA. "The Voyagers owe their ability to operate at such great distances from the Sun to their nuclear electric power sources, which provide the electrical power they need to function."

The Sun emits a steady flow of electrically charged particles called the solar wind. As the solar wind expands supersonically into space, it creates a magnetized bubble around the Sun, called the heliosphere. Eventually, the solar wind encounters the electrically charged particles and magnetic field in the interstellar gas. The boundary created between the solar wind and interstellar gas is the heliopause. Before the spacecraft reach the heliopause, they will pass through the termination shock -- the zone in which the solar wind abruptly slows down from supersonic to subsonic speed.

Reaching the termination shock and heliopause will be major milestones for the spacecraft because no one has been there before and the Voyagers will gather the first direct evidence of their structure. Encountering the termination shock and heliopause has been a long-sought goal for many space physicists, and exactly where these two boundaries are located and what they are like still remains a mystery.

"Based on current data from the Voyager cosmic ray subsystem, we are predicting the termination shock to be in the range of 62 to 90 astronomical units (AU) from the Sun. Most 'consensus' estimates are currently converging on about 85 AU. Voyager 1 is currently at about 67 AU and moving outwards at 3.5 AU per year, so I would expect crossing the termination shock sometime before the end of 2003," said Dr. Alan Cummings, a co- investigator on the cosmic ray subsystem at the California Institute of Technology.

"Based on a radio emission event detected by the Voyager 1 and 2 plasma wave instruments in 1992, we estimate that the heliopause is located at110 to 160 AU from the Sun," said Dr. Donald A. Gurnett, principal investigator on the plasma wave subsystem at the University of Iowa. (One AU is equal to 150 million kilometers, or 93 million miles, or the distance from the Earth to the Sun.)

"The low-energy charged particle instruments on the two spacecraft continue to detect ions and electrons accelerated at the Sun and at huge shock waves, tens of AU in radius, that are driven outward through the solar wind. During the past five years, we have observed marked variations in this ion population, but have yet to see clear evidence of the termination shock. We should always keep in mind that our theories may be incomplete and the shock may be a lot farther out than we think," said Dr. Stamatios M. Krimigis, principal investigator for the low energy charged particle subsystem at The Johns Hopkins University Applied Physics Laboratory.

Voyager 2 was launched first on Aug. 20, 1977 and Voyager 1 was launched a few weeks later on a faster trajectory on Sept. 5. Initially both spacecraft were only supposed to explore two planets -- Jupiter and Saturn. But the incredible success of those two first encounters and the good health of the spacecraft prompted NASA to extend Voyager 2's mission on to Uranus and Neptune. As the spacecraft flew across the solar system, remote-control reprogramming has given the Voyagers greater capabilities than they possessed when they left the Earth.

There are four other science instruments that are still functioning and collecting data as part of the Voyager Interstellar Mission. The plasma subsystem measures the protons in the solar wind. "Our instrument has recently observed a slow, year-long increase in the speed of the solar wind which peaked in late 1996, and we are now observing a slow decrease in solar wind velocity," said Dr. John Richardson, of the Massachusetts Institute of Technology, principal investigator on the plasma subsystem. "We think the velocity peak coincided with the recent solar minimum. As we approach the solar maximum in 2000 the solar wind pressure should decrease, which will result in the termination shock and heliopause moving inward towards the Voyager spacecraft."

The magnetometer on board the Voyagers measures the magnetic fields that are carried out into interplanetary space by the solar wind. The Voyagers are currently measuring the weakest interplanetary magnetic fields ever detected and those magnetic fields being measured are responsive to charged particles that cannot be detected directly by any other instruments on the spacecraft, according to Dr. Norman Ness, principal investigator on the magnetometer subsystem at the Bartol Research Institute, University of Delaware.

Other science instruments still collecting data include the planetary radio astronomy subsystem and the ultraviolet spectrometer subsystem.

Voyager 1 encountered Jupiter on March 5, 1979, and Saturn on November 12, 1980 and then, because its trajectory was designed to fly close to Saturn's large moon Titan, Voyager 1's path was bent northward by Saturn's gravity, sending the spacecraft out of the ecliptic plane, the plane in which all the planets except Pluto orbit the Sun. Voyager 2 arrived at Jupiter on July 9, 1979, and Saturn on August 25, 1981, and was then sent on to Uranus on January 25, 1986 and Neptune on August 25, 1989. Neptune's gravity bent Voyager 2's path southward, sending it out of the ecliptic plane as well and on toward interstellar space.

Both spacecraft have enough electrical power and attitude control propellant to continue operating until about 2020, when the available electrical power will no longer support science instrument operation. Spacecraft electrical power is supplied by Radioisotope Thermoelectric Generators (RTGs) that provided approximately 470 watts power at launch. Due to the natural radioactive decay of the plutonium fuel source, the electrical energy provided by the RTGs is continually declining. At the beginning of 1997, the power generated by Voyager 1 had dropped to 334 watts and to 336 watts for Voyager 2. Both of these power levels represent better performance than had been predicted before launch.

The Voyagers are now so far from home that it takes nine hours for a radio signal traveling at the speed of light to reach the spacecraft. Science data are returned to Earth in real-time to the 34-meter Deep Space Network (DSN) antennas located in California, Australia and Spain. Voyager 1 will pass the Pioneer 10 spacecraft in January 1998 to become the most distant human- made object in our solar system.

Voyager 1 is currently 10.1 billion kilometers (6.3 billion miles) from Earth, having traveled 11.9 billion kilometers (7.4 billion miles) since its launch. The Voyager 1 spacecraft is departing the solar system at a speed of 17.4 kilometers per second (39,000 miles per hour).

Voyager 2 is currently 7.9 billion kilometers (4.9 billion miles) from Earth, having traveled 11.3 billion kilometers (6.9 billion miles) since its launch. The Voyager 2 spacecraft is departing the solar system at a speed of 15.9 kilometers per second (35,000 miles per hour).

JPL, a division of the California Institute of Technology, manages the Voyager Interstellar Mission for NASA's Office of Space Science, Washington, D. C.

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Voyager 2’s Discoveries From Interstellar Space

In its journey beyond the boundary of the solar wind’s bubble, the probe observed some notable differences from its twin, Voyager 1.

By Kenneth Chang

The Voyager 2 spacecraft burst out of the bubble of gases expanding from the sun and into the wild of the Milky Way a year ago. It was the second spacecraft to cross that boundary and directly observe the interstellar medium. Its faster-moving twin, Voyager 1, made the crossing six years earlier, in August 2012.

Launched 42 years ago, when Jimmy Carter was president, the twin spacecraft have persisted far longer than envisioned, as has their ability to send scientific findings home to Earth.

In a series of papers published on Monday in Nature Astronomy, scientists report what Voyager 2 observed at the boundary of the solar wind’s bubble and beyond.

“We’re certainly surprised,” Edward C. Stone, the mission’s project scientist, said of the probe’s longevity during a news conference on Thursday. “We’re also wonderfully excited by the fact that they do. When the two Voyagers were launched, the space age was only 20 years old. It was hard to know at that time that anything could last over 40 years.”

In many ways, the measurements echoed Voyager 1’s: a jump in the density of particles accompanied by a sharp decrease in their speed, a shift in the magnetic fields.

Voyager 2 also noted some differences, which could give clues about the complicated dynamics in that region of the solar system.

The sun spews in all directions a continuous stream of particles called the solar wind traveling at a speed of a million miles per hour. The particles are mostly hydrogen, but, heated to some 3 million degrees Fahrenheit, the atoms are ripped apart into protons and electrons.

At a distance of more than 11 billion miles from the sun, the solar wind, thinning out, is increasingly buffeted by the flow of particles in the interstellar wind and a galactic magnetic field generated by the long ago explosions of distant stars. The interstellar wind is much cooler — just tens of thousands of degrees — and denser.

Voyager 2 is heading in a different direction than Voyager 1, which could explain some of the differences. The sun was also more active in 2012, near the maximum phase of its cycle of activity. The sun is now near its lull, known as the solar minimum.

With Voyager 1, the outward velocity of the solar wind dropped to zero long before the boundary; it was pushed sideways. With Voyager 2, the outward velocities fluctuated, sometimes dipping to zero but then rising again.

Curiously, the distances from the sun for the two crossings out of the solar system were similar. Scientists had expected that the bubble would be pushed outward during the solar maximum and collapse inward during the solar minimum.

“A lot of the models leave a lot to be desired,” Stamatios Krimigis, a scientists at the Johns Hopkins Applied Physics Laboratory in Laurel, Md., and the principal investigator of one of the Voyager instruments, said in an interview.

Voyager 2 also measured what scientists describe as a magnetic barrier, “like the pile-up of slowly moving cars on a major highway, a few miles ahead of the scene of an accident,” Leonard F. Burlaga, a scientist working with the spacecraft’s magnetometer, wrote in an email.

When solar wind slows, the density of particles increases and the magnetic field strengthens.

“Again, it’s like the cars, which turn away from the lanes of the accident and move slowly along the available lanes,” Dr. Burlaga said. “The cars are more densely spaced, the drivers are heated, but they eventually move along.”

The missions were originally designed to last four years to fly by Jupiter and Saturn. Voyager 2 also visited Uranus and Neptune. Voyager 2 still has five functioning instruments for measuring the void; Voyager 1 has four.

Both Voyagers are expected to last another five years or so until their batteries die out. Both are powered by electricity generated by the heat of radioactive plutonium. As the plutonium diminishes, the spacecraft receive less and less energy.

Once the Voyagers shut down, there will be no more data from beyond our solar system for years. Only one other spacecraft, the New Horizons probe that flew by Pluto in 2015 and visited another object in the distant Kuiper belt in January this year, is headed that way. But it is moving more slowly and its plutonium power will run out before it reaches interstellar space.

“Right now, when the Voyagers go offline, that’s kind of it unless we do something else,” said Ralph McNutt, a physicist at the Johns Hopkins Applied Physics Laboratory.

Dr. McNutt is leading a study to look at what it might take to build an ultrafast spacecraft that could leave the solar system in a hurry. The development of NASA’s long-delayed giant rocket, the Space Launch System, makes that mission more plausible.

The mission could also perform what is known as an Oberth maneuver, named after Hermann Oberth, a German physicist who came up with the idea in 1927. A probe would first head to Jupiter, using the giant planet’s gravity to accelerate toward the sun. As it then swings around the sun, the spacecraft would fire a rocket engine, accelerating to a speed where it could cover close to a couple of billion miles a year. That would be more than five times the speed of the Voyagers.

That would be tricky to pull off, however. For such a powered flyby to be effective, the probe would have to travel within a million miles or so from the sun.

“Well, it’s not as easy as it sounds,” said Dr. Krimigis, who is taking part in the study which should be completed in a couple of years. “At that distance, every metal we know melts.”

Kenneth Chang has been at The Times since 2000, writing about physics, geology, chemistry, and the planets. Before becoming a science writer, he was a graduate student whose research involved the control of chaos. More about Kenneth Chang

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Voyager 2 Gets a Life-Extending Power Boost in Deep Space

NASA engineers have come up with a power-saving strategy to eke more time—and more science—out of the Voyager probes, humanity’s longest-running spacecraft , as they continue venturing into unexplored reaches of interstellar space.

And time is of the essence: Voyager 1 and 2 have been flying since 1977, and their power sources have been gradually fading, putting their instruments at risk. Out in the vast abyss of deep space, unfathomably far from our sun, solar power isn’t viable. That’s why engineers equipped each Voyager with a trio of radioisotope thermoelectric generators , or RTGs. These work by converting the heat from the decay of radioisotope fuel, plutonium-238, into electricity. They’re basically nuclear batteries—and they’re finally running out of juice, losing a predictable 4 watts per year. While the Voyagers don’t need that power for propulsion, it’s essential to their ability to collect scientific readings of far-flung charged particles and magnetic fields—so far, humanity’s only opportunity to sample that data in interstellar space.

A couple of years ago, NASA began exploring ways to keep the Voyagers’ instruments running as long as possible. The first move, in 2019, was to start turning off the heaters for the science instruments. That worked; the devices kept working despite temperatures dropping some 50 degrees Celsius, much colder than the conditions they’d been tested in. But it still wasn’t enough, so at the end of March, a NASA team initiated an energy-saving strategy on Voyager 2 that dips into some reserve power meant to protect systems from voltage spikes.

While this strategy does leave the craft more vulnerable, the risk of such spikes seems to be very low, says Suzanne Dodd, the Voyager project manager at NASA’s Jet Propulsion Laboratory in Southern California. Assuming all goes well, they’ll start similar voltage management on Voyager 1 as early as this fall. Altogether, Dodd thinks this could buy the probes’ science mission a few extra years. Voyager is still a mission of discovery, she says, and every piece of data the spacecraft obtain in interstellar space is valuable. “I continue to be amazed by these spacecraft and by the engineers who come up with clever ways to operate them,” says Dodd.

Now 45 years old, the Voyagers spent their first two decades flying through the solar system, snapping photos of Jupiter, Saturn, Uranus, and Neptune as they zoomed by. Voyager 1 also captured the iconic “ pale blue dot ” photograph of a tiny, distant Earth. As they kept going, they continued capturing data. They have long outlived their predecessors, Pioneer 10 and 11 , which were the first probes to fly by the gas giants but shut down more than 20 years ago. Both Voyagers have flown well beyond the Kuiper belt, a region hosting Pluto and other small, icy bodies. In 2012, Voyager 1 left the heliosphere, the protective bubble of particles and magnetic fields generated by the sun, beyond which lies the interstellar medium. Its twin followed six years later, at which point both were officially in interstellar territory, cruising at 35,000 miles per hour into the unknown.

Today, Voyager 1 is 159 astronomical units from home, and Voyager 2 is at 133 AU, traveling in a different direction. (1 AU is the distance between the Earth and sun, or about 93 million miles.) The spacecraft are surely showing signs of age—the team dealt with telemetry problems on Voyager 1 last year—but the cosmic workhorses are continuing on .

It’s not uncommon for NASA missions to far outlive their expected lifetimes, and to be granted extensions after achieving their main objectives. The Opportunity Mars rover rolled on for nearly 15 years , rather than three months. The Saturn-focused Cassini orbiter, which NASA operated in collaboration with the European Space Agency, persevered for 20 years instead of four. But the Voyagers surely take the cosmic cake. If the energy-conserving gambit of Dodd’s team works, the two could reach the unprecedented age of 50—with a “stretch goal” of reaching 200 AU around the year 2035.

But this will require sacrificing the science instruments one by one.

Voyager 2 still has five instruments humming along: a magnetometer, a plasma wave surveyor, a plasma science experiment, a cosmic ray detector, and a low-energy charged particle detector. The first two only take about 2W to run, and their electronics are in the body of the probe, so they’ll probably be the last to be shut down. The others are housed on the boom of the craft, where it’s frigid, and they use between 3 and  5 watts each, so turning each one of them off would buy another year of life.

Interstellar space might seem completely empty, but it’s not: There are still solar particles and magnetic phenomena to study. “The further we get from the sun, the more interesting it gets because we really don’t know what we might find. And having two Voyager spacecraft is like seeing through binoculars,” says Linda Spilker, the Voyager project scientist at JPL. For instance, astrophysicists expected that outside the heliosphere, the sun’s magnetic field would slowly rotate into the direction of the interstellar medium, and the Voyagers would be able to track that. But they’ve seen no such rotation yet, Spilker says, suggesting models of the magnetic fields need updating.

The spacecraft have also used their instruments to survey interstellar material and to detect radiation from a dazzlingly bright gamma-ray burst in another galaxy last October.

Missions based on newer probes will take advantage of Voyager’s ongoing solar science. As early as 2025, NASA plans to launch the Interstellar Mapping and Acceleration Probe (IMAP) to survey the heliosphere. The Voyagers are already well outside of the heliosphere, so the measurements from the distant probes can be compared to those from the much closer new one. “Having the Voyagers out there during IMAP will be really wonderful. As we’re seeing imaging with IMAP, the Voyagers are also going to be making valuable measurements locally,” says David McComas, a Princeton physicist who leads the IMAP collaboration. He likens it to doctors taking a CAT scan of a person’s brain for the big picture, plus a biopsy for detailed information.

The Voyagers aren’t done yet, but they already have an impressive legacy. That includes NASA’s New Horizons probe, which glided by Pluto in 2015 . Now 55 AU away from Earth, that spacecraft is probing the edge of the heliosphere with newer, better sensors than the Voyagers are equipped with, and it has already taken images of objects that hadn’t even been discovered when the Voyagers launched, like Pluto’s moons and a Kuiper Belt object called Arrokoth . “For all of us at New Horizons, the Voyager team, they are our heroes,” says Alan Stern, the collaboration’s principal investigator and a planetary scientist at the Southwest Research Institute. New Horizons is the only other distant human-made probe still operating, and it could last until 2050, Stern says. The team is now looking for a new target for a flyby.

Inspired by the Voyagers’ tremendous success, engineers are already designing next-generation spacecraft concepts, such as those that could be powered by lasers and lightsails and could one day whiz into our interstellar environs faster and farther than 1970s probes could. What advice should they glean from the Voyagers’ long and healthy lives? First, says Dodd, it’s useful to have plenty of fuel and redundant systems, because even robust instruments eventually fail. And it’s important to pass knowledge on, she says, in case the craft outlives the generation of engineers who designed it.

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Voyager 2: An iconic spacecraft that's still exploring 45 years on

The interstellar vagabond continues to explore the cosmos along with its twin, Voyager 1.

Voyager 2 as the backup

Jupiter and saturn flyby, uranus and neptune flyby, voyager 2's interstellar adventure, voyager 2's legacy, additional information.

Voyager 2, was the first of two twin probes NASA sent to investigate the outer planets of our solar system. 

The probe was launched aboard a Titan IIIE-Centaur from Cape Canaveral Space Launch Complex 41 (previously Launch Complex 41) on Aug. 20, 1977, its twin spacecraft Voyager 1 was launched about two weeks later on Sept. 5. NASA planned for the Voyager spacecraft to take advantage of an alignment of the outer planets that takes place only every 176 years. The alignment would allow both probes to swing from one planet to the next, with a gravity boost to help them along the way.

While Voyager 1 focused on Jupiter and Saturn , Voyager 2 visited both those planets and also ventured to Uranus and Neptune. Voyager 2's mission to those last two planets would be humanity's only visit in the 20th century.

Related: Celebrate 45 years of Voyager with these amazing images of our solar system (gallery)

Voyager 2 is now traveling through interstellar space. As of early November 2018, NASA announced that Voyager 2 had crossed the outer edge of our solar system ( Voyager 1 crossed the boundary into interstellar space in 2012. ) Voyager 2 is now approximately 12 billion miles (19 billion kilometers) away from Earth and counting!  

Although there was not enough money in Voyager 2's budget to guarantee it would still work when flying past Uranus and Neptune, its trajectory was designed to go past those planets anyway. If the spacecraft were still working after Saturn, NASA could try to take pictures of the other planets.

Voyager 2 was ready as a backup for Voyager 1. If Voyager 1 failed when taking pictures of Jupiter and Saturn, NASA was prepared to alter Voyager 2's path to follow Voyager 1's trajectory. It would cut off the Uranus and Neptune option, but still, preserve the possibility of capturing images.

The backup plan was never executed, though, because Voyager 1 went on to make many discoveries at Jupiter and Saturn, working well enough for NASA to carry out its original plans for Voyager 2.

Voyager 2 reached Jupiter in 1979, two years after launching from Cape Canaveral. Since Voyager 1 had just gone through the system four months earlier, Voyager 2's arrival allowed NASA to take valuable comparison shots of Jupiter and its moons. It captured changes in the Great Red Spot and also resolved some of the moon's surfaces in greater detail.

Voyager 2 took pictures of many of Jupiter's satellites. Among its most spectacular findings were pictures from the icy moon Europa . Voyager 2 snapped detailed photos of the icy moon's cracks from 128,000 miles (205,996 km) away and revealed no change in elevation anywhere on the moon's surface.

Proving that moons are abundant around the outer planets, Voyager 2 happened to image Adrastea, a small moon of Jupiter, only months after Voyager 1 found two other Jupiter moons, Thebe and Metis. Adrastea is exceptionally small, only about 19 miles (30.5 kilometers) in diameter at the smallest estimate.

Next in line was Saturn. Voyager 2  became the third spacecraft to visit Saturn when it arrived at its closest point to the ringed planet on Aug. 26, 1981, and took hundreds of pictures of the planet, its moons and its rings . Suspecting that Saturn might be circled by many ringlets, scientists conducted an experiment. They watched the star Delta Scorpii for nearly two and a half hours as it passed through the plane of the rings. As expected, the star's flickering light revealed ringlets as small as 330 feet (100 meters) in diameter. 

Voyager 2's made its closest approach to Uranus on Jan. 24, 1986, becoming the first spacecraft to visit the ice giant. The probe made several observations of the planet, noting that the south pole was facing the sun and that its atmosphere is about 85% hydrogen and 15% helium. 

Additionally, Voyager 2 discovered rings around Uranus, 10 new moons and a magnetic field that, oddly, was 55 degrees off the planet's axis. Astronomers are still puzzling over Uranus' orientation today.

Voyager 2's pictures of the moon Miranda revealed it to be perhaps the strangest moon in the solar system. Its jumbled-up surface appears as though it was pushed together and broken apart several times.

The spacecraft then made it to Neptune , reaching the closest point on Aug. 25, 1989. It skimmed about 3,000 miles from the top of the planet's atmosphere and spotted five new moons as well as four rings around the planet. Remarkably, Voyager 2 is currently the only human-made object to have flown by the intriguing ice giant, according to NASA .

On November 5, 2018, Voyager 2 crossed the heliopause — the boundary between the heliosphere and interstellar space. At this stage, the probe was 119 astronomical units from the sun. (One AU is the average Earth-sun distance, which is about 93 million miles, or 150 million kilometers.) Voyager 1 made the crossing at nearly the same distance, 121.6 AU.

According to NASA Jet Propulsion Laboratory (JPL) , Voyager 2 has enough fuel to keep its instruments running until at least 2025. By then, the spacecraft will be approximately 11.4 billion miles (18.4 billion kilometers) away from the sun. 

But Voyager 2 is destined to roam the Milky Way long after its instruments have stopped working.

In about 40,000 years Voyager 2 will pass 1.7 light-years (9.7 trillion miles) from the star Ross 248, according to NASA JPL. The cosmic vagabond will continue its journey through interstellar space and pass 4.3 light-years, (25 trillion miles) from Sirius in about 296,000 years. 

Voyager 2's observations paved the way for later missions. The Cassini spacecraft, which was at Saturn between 2004 and 2017, tracked down evidence of liquid water at the planet's icy moons several decades after the Voyagers initially revealed the possible presence of water. Cassini also mapped the moon, Titan , after the Voyagers took pictures of its thick atmosphere.

Voyager 2's images of Uranus and Neptune also serve as a baseline for current observations of those giant planets. In 2014, astronomers were surprised to see giant storms on Uranus — a big change from when Voyager 2 flew by the planet in 1986. 

To see where Voyager 2 is now you can check out the mission status with resources from NASA . Learn more about the iconic spacecraft with the National Air and Space Museum .  

Bibliography

NASA. In depth: Voyager 2. NASA. Retrieved August 17, 2022, from www.solarsystem.nasa.gov/missions/voyager-2/in-depth/

NASA. Voyager - mission status. NASA. Retrieved August 17, 2022, from www.voyager.jpl.nasa.gov/mission/status/

NASA. Voyager - the interstellar mission. NASA. Retrieved August 17, 2022, from www. voyager.jpl.nasa.gov/mission/interstellar-mission

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Elizabeth Howell (she/her), Ph.D., is a staff writer in the spaceflight channel since 2022 covering diversity, education and gaming as well. She was contributing writer for Space.com for 10 years before joining full-time. Elizabeth's reporting includes multiple exclusives with the White House and Office of the Vice-President of the United States, an exclusive conversation with aspiring space tourist (and NSYNC bassist) Lance Bass, speaking several times with the International Space Station, witnessing five human spaceflight launches on two continents, flying parabolic, working inside a spacesuit, and participating in a simulated Mars mission. Her latest book, " Why Am I Taller ?", is co-written with astronaut Dave Williams. Elizabeth holds a Ph.D. and M.Sc. in Space Studies from the University of North Dakota, a Bachelor of Journalism from Canada's Carleton University and a Bachelor of History from Canada's Athabasca University. Elizabeth is also a post-secondary instructor in communications and science at several institutions since 2015; her experience includes developing and teaching an astronomy course at Canada's Algonquin College (with Indigenous content as well) to more than 1,000 students since 2020. Elizabeth first got interested in space after watching the movie Apollo 13 in 1996, and still wants to be an astronaut someday. Mastodon: https://qoto.org/@howellspace

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Voyager 2 live position and data

This page shows Voyager 2 location and other relevant astronomical data in real time. The celestial coordinates, magnitude, distances and speed are updated in real time and are computed using high quality data sets provided by the JPL Horizons ephemeris service (see acknowledgements for details). The sky map shown in the background represents a rectangular portion of the sky 60x40 arcminutes wide. By comparison the diameter of the full Moon is about 30 arcmins, so the full horizontal extent of the map is approximately 2 full Moons wide. Depending on the device you are using, the map can be dragged horizondally or vertically using the mouse or touchscreen. The deep sky image in the background is provided by the Digitized Sky Survey ( acknowledgements ).

Current close conjunctions

List of bright objects (stars brighter than magnitude 9.0 and galaxies brighter than magmitude 14.0) close to Voyager 2 (less than 1.5 degrees):

Additional resources

• 15 Days Ephemerides
• Interactive Sky Map (Planetarium)
• Rise & Set Times
• Distance from Earth

Astronomy databases

• The Digitized Sky Survey, a photographic survey of the whole sky created using images from different telescopes, including the Oschin Schmidt Telescope on Palomar Mountain
• The Hipparcos Star Catalogue, containing more than 100.000 bright stars
• The PGC 2003 Catalogue, containing information about 1 million galaxies
• The GSC 2.3 Catalogue, containing information about more than 2 billion stars and galaxies

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Nasa’s voyager will do more science with new power strategy, jet propulsion laboratory, power to the probes, more about the mission.

The plan will keep Voyager 2’s science instruments turned on a few years longer than previously anticipated, enabling yet more revelations from interstellar space.

Editor’s note: Language was added in the second paragraph on May 1 to underscore that the mission will continue even after a science instrument is retired.

Launched in 1977, the Voyager 2 spacecraft is more than 12 billion miles (20 billion kilometers) from Earth, using five science instruments to study interstellar space. To help keep those instruments operating despite a diminishing power supply, the aging spacecraft has begun using a small reservoir of backup power set aside as part of an onboard safety mechanism. The move will enable the mission to postpone shutting down a science instrument until 2026, rather than this year.

Switching off a science instrument will not end the mission. After shutting off the one instrument in 2026, the probe will continue to operate four science instruments until the declining power supply requires another to be turned off. If Voyager 2 remains healthy, the engineering team anticipates the mission could potentially continue for years to come

Voyager 2 and its twin Voyager 1 are the only spacecraft ever to operate outside the heliosphere, the protective bubble of particles and magnetic fields generated by the Sun. The probes are helping scientists answer questions about the shape of the heliosphere and its role in protecting Earth from the energetic particles and other radiation found in the interstellar environment.

“The science data that the Voyagers are returning gets more valuable the farther away from the Sun they go, so we are definitely interested in keeping as many science instruments operating as long as possible,” said Linda Spilker, Voyager’s project scientist at NASA’s Jet Propulsion Laboratory in Southern California, which manages the mission for NASA.

Both Voyager probes power themselves with radioisotope thermoelectric generators (RTGs), which convert heat from decaying plutonium into electricity. The continual decay process means the generator produces slightly less power each year. So far, the declining power supply hasn’t impacted the mission’s science output, but to compensate for the loss, engineers have turned off heaters and other systems that are not essential to keeping the spacecraft flying.

With those options now exhausted on Voyager 2, one of the spacecraft’s five science instruments was next on their list. (Voyager 1 is operating one less science instrument than its twin because an instrument failed early in the mission. As a result, the decision about whether to turn off an instrument on Voyager 1 won’t come until sometime next year.)

In search of a way to avoid shutting down a Voyager 2 science instrument, the team took a closer look at a safety mechanism designed to protect the instruments in case the spacecraft’s voltage – the flow of electricity – changes significantly. Because a fluctuation in voltage could damage the instruments, Voyager is equipped with a voltage regulator that triggers a backup circuit in such an event. The circuit can access a small amount of power from the RTG that’s set aside for this purpose. Instead of reserving that power, the mission will now be using it to keep the science instruments operating.

Although the spacecraft’s voltage will not be tightly regulated as a result, even after more than 45 years in flight, the electrical systems on both probes remain relatively stable, minimizing the need for a safety net. The engineering team is also able to monitor the voltage and respond if it fluctuates too much. If the new approach works well for Voyager 2, the team may implement it on Voyager 1 as well.

“Variable voltages pose a risk to the instruments, but we’ve determined that it’s a small risk, and the alternative offers a big reward of being able to keep the science instruments turned on longer,” said Suzanne Dodd, Voyager’s project manager at JPL. “We’ve been monitoring the spacecraft for a few weeks, and it seems like this new approach is working.”

The Voyager mission was originally scheduled to last only four years, sending both probes past Saturn and Jupiter. NASA extended the mission so that Voyager 2 could visit Neptune and Uranus; it is still the only spacecraft ever to have encountered the ice giants. In 1990, NASA extended the mission again, this time with the goal of sending the probes outside the heliosphere. Voyager 1 reached the boundary in 2012, while Voyager 2 (traveling slower and in a different direction than its twin) reached it in 2018.

A division of Caltech in Pasadena, JPL built and operates the Voyager spacecraft. The Voyager missions are a part of the NASA Heliophysics System Observatory, sponsored by the Heliophysics Division of the Science Mission Directorate in Washington.

For more information about the Voyager spacecraft, visit:

https://www.nasa.gov/voyager

Calla Cofield Jet Propulsion Laboratory, Pasadena, Calif. 626-808-2469 [email protected]

Voyager 2 Trajectory through the Solar System

This visualization tracks the trajectory of the Voyager 2 spacecraft through the solar system. Launched on August 20, 1977, it was one of two spacecraft sent to visit the giant planets of the outer solar system.

Like Voyager 1, Voyager 2 flew by Jupiter and Saturn, but the Voyager 2 mission was extended to fly by Uranus and Neptune before being directed out of the solar system.

To fit the 40-year history of the mission into a short visualization, the pacing of time accelerates through most of the movie, starting at about 5 days per second at the beginning and speeding up to about 11 months per second after the planet flybys are passed.

The termination shock and heliopause are the 'boundaries' created when the plasma between the stars interacts with the plasma flowing outward from the Sun. They are represented with simple grid models and oriented so their 'nose' is pointed in the direction (Right Ascension = 17h 24m, declination = 17 degrees south) represented by more recent measurements from other missions.