nasa voyager interstellar

Voyager 1 and 2: The Interstellar Mission

An image of Neptune taken by the Voyager 2 spacecraft. Image credit: NASA

NASA has beautiful photos of every planet in our solar system. We even have images of faraway Neptune , as you can see in the photo above.

Neptune is much too distant for an astronaut to travel there with a camera. So, how do we have pictures from distant locations in our solar system? Our photographers were two spacecraft, called Voyager 1 and Voyager 2!

An artist’s rendering of one of the Voyager spacecraft. Image credit: NASA

The Voyager 1 and 2 spacecraft launched from Earth in 1977. Their mission was to explore Jupiter and Saturn —and beyond to the outer planets of our solar system. This was a big task. No human-made object had ever attempted a journey like that before.

The two spacecraft took tens of thousands of pictures of Jupiter and Saturn and their moons. The pictures from Voyager 1 and 2 allowed us to see lots of things for the first time. For example, they captured detailed photos of Jupiter's clouds and storms, and the structure of Saturn's rings .

Image of storms on Jupiter taken by the Voyager 1 spacecraft. Image credit: NASA

Voyager 1 and 2 also discovered active volcanoes on Jupiter's moon Io , and much more. Voyager 2 also took pictures of Uranus and Neptune. Together, the Voyager missions discovered 22 moons.

Since then, these spacecraft have continued to travel farther away from us. Voyager 1 and 2 are now so far away that they are in interstellar space —the region between the stars. No other spacecraft have ever flown this far away.

Where will Voyager go next?

Watch this video to find out what's beyond our solar system!

Both spacecraft are still sending information back to Earth. This data will help us learn about conditions in the distant solar system and interstellar space.

The Voyagers have enough fuel and power to operate until 2025 and beyond. Sometime after this they will not be able to communicate with Earth anymore. Unless something stops them, they will continue to travel on and on, passing other stars after many thousands of years.

Each Voyager spacecraft also carries a message. Both spacecraft carry a golden record with scenes and sounds from Earth. The records also contain music and greetings in different languages. So, if intelligent life ever find these spacecraft, they may learn something about Earth and us as well!

A photo of the golden record that was sent into space on both Voyager 1 and Voyager 2. Image credit: NASA/JPL-Caltech

More about our universe!

Where does interstellar space begin?

Searching for other planets like ours

Play Galactic Explorer!

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As NASA’s Voyager 1 Surveys Interstellar Space, Its Density Measurements Are Making Waves

An illustration depicting one of NASA’s twin Voyager spacecraft. Both Voyagers have entered interstellar space, or the space outside our Sun’s heliosphere. Credit: NASA/JPL-Caltech Full Image Details

In the sparse collection of atoms that fills interstellar space, Voyager 1 has measured a long-lasting series of waves where it previously only detected sporadic bursts.

Until recently, every spacecraft in history had made all of its measurements inside our heliosphere , the magnetic bubble inflated by our Sun. But on Aug. 25, 2012, NASA’s Voyager 1 changed that. As it crossed the heliosphere’s boundary , it became the first human-made object to enter – and measure – interstellar space. Now eight years into its interstellar journey, a close listen of Voyager 1’s data is yielding new insights into what that frontier is like.

If our heliosphere is a ship sailing interstellar waters, Voyager 1 is a life raft just dropped from the deck, determined to survey the currents. For now, any rough waters it feels are mostly from our heliosphere’s wake. But farther out, it will sense the stirrings from sources deeper in the cosmos. Eventually, our heliosphere’s presence will fade from its measurements completely.

“We have some ideas about how far Voyager will need to get to start seeing more pure interstellar waters, so to speak,” said Stella Ocker, a Ph.D. student at Cornell University in Ithaca, New York, and the newest member of the Voyager team. “But we’re not entirely sure when we’ll reach that point.”

Ocker’s new study, published on Monday in Nature Astronomy , reports what may be the first continuous measurement of the density of material in interstellar space. “This detection offers us a new way to measure the density of interstellar space and opens up a new pathway for us to explore the structure of the very nearby interstellar medium,” Ocker said.

When one pictures the stuff between the stars – astronomers call it the “interstellar medium,” a spread-out soup of particles and radiation – one might reimagine a calm, silent, serene environment. That would be a mistake.

“I have used the phrase ‘the quiescent interstellar medium’ – but you can find lots of places that are not particularly quiescent,” said Jim Cordes, space physicist at Cornell and co-author of the paper.

Like the ocean, the interstellar medium is full of turbulent waves. The largest come from our galaxy’s rotation, as space smears against itself and sets forth undulations tens of light-years across. Smaller (though still gigantic) waves rush from supernova blasts, stretching billions of miles from crest to crest. The smallest ripples are usually from our own Sun, as solar eruptions send shockwaves through space that permeate our heliosphere’s lining.

These crashing waves reveal clues about the density of the interstellar medium – a value that affects our understanding of the shape of our heliosphere, how stars form, and even our own location in the galaxy. As these waves reverberate through space, they vibrate the electrons around them, which ring out at characteristic frequencies depending on how crammed together they are. The higher the pitch of that ringing, the higher the electron density. Voyager 1’s Plasma Wave Subsystem – which includes two “bunny ear” antennas sticking out 30 feet (10 meters) behind the spacecraft – was designed to hear that ringing.

An illustration of NASA's Voyager spacecraft showing the antennas used by the Plasma Wave Subsystem and other instruments. Credit: NASA/JPL-Caltech Full Image Details

In November 2012, three months after exiting the heliosphere, Voyager 1 heard interstellar sounds for the first time. Six months later, another “whistle” appeared – this time louder and even higher pitched. The interstellar medium appeared to be getting thicker, and quickly.

NASA’s Voyager 1 spacecraft captured these sounds of interstellar space. Voyager 1’s plasma wave instrument detected the vibrations of dense interstellar plasma, or ionized gas, from October to November 2012 and April to May 2013.

These momentary whistles continue at irregular intervals in Voyager’s data today. They’re an excellent way to study the interstellar medium’s density, but it does take some patience.

“They’ve only been seen about once a year, so relying on these kind of fortuitous events meant that our map of the density of interstellar space was kind of sparse,” Ocker said.

Ocker set out to find a running measure of interstellar medium density to fill in the gaps – one that doesn’t depend on the occasional shockwaves propagating out from the Sun. After filtering through Voyager 1’s data, looking for weak but consistent signals, she found a promising candidate. It started to pick up in mid-2017, right around the time of another whistle.

“It’s virtually a single tone,” said Ocker. “And over time, we do hear it change – but the way the frequency moves around tells us how the density is changing.”

Weak but nearly continuous plasma oscillation events – visible as a thin red line in this graphic/tk – connect stronger events in Voyager 1’s Plasma Wave Subsystem data. Use the slider to switch between graphs showing only the strong signals (blue background) and the filtered data showing weaker signals. Credit: NASA/JPL-Caltech/Stella Ocker

Ocker calls the new signal a plasma wave emission, and it, too, appeared to track the density of interstellar space. When the abrupt whistles appeared in the data, the tone of the emission rises and falls with them. The signal also resembles one observed in Earth’s upper atmosphere that’s known to track with the electron density there.

“This is really exciting, because we are able to regularly sample the density over a very long stretch of space, the longest stretch of space that we have so far,” said Ocker. “This provides us with the most complete map of the density and the interstellar medium as seen by Voyager.”

Get the Latest JPL News

Based on the signal, electron density around Voyager 1 started rising in 2013 and reached its current levels about mid-2015, a roughly 40-fold increase in density. The spacecraft appears to be in a similar density range, with some fluctuations, through the entire dataset they analyzed which ended in early 2020.

Ocker and her colleagues are currently trying to develop a physical model of how the plasma wave emission is produced that will be key to interpreting it. In the meantime, Voyager 1’s Plasma Wave Subsystem keeps sending back data farther and farther from home, where every new discovery has the potential to make us reimagining our home in the cosmos.

The Voyager spacecraft were built by NASA’s Jet Propulsion Laboratory, which continues to operate both. JPL is a division of Caltech in Pasadena. 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

https://voyager.jpl.nasa.gov

News Media Contact

Calla Cofield

Jet Propulsion Laboratory, Pasadena, Calif.

626-808-2469

[email protected]

Written by Miles Hatfield

Astronomy Picture of the Day

Voyager Reaches Interstellar Space

After decades of exploration, Voyager 1 reaches a historic milestone for mankind, interstellar space.

Transcript:

(Music) Voyager 1 has left the bubble around the sun and entered interstellar space the space between stars.

It's amazing that Voyager has operated 36 years.

(sound of launch)

Launched in 1977, travelled passed the gas giant planets in our solar system and now off into interstellar space. It's a great journey.

We have an instrument on Voyager, which can measure the density of the ions, the plasma, which is out there.

In March of 2012 it turns out there was a massive eruption from the sun, which eventually reached Voyager 1 in April of 2013.

When that blast wave reached Voyager, it caused the plasma around Voyager to vibrate or oscillate in a certain particular tone.

Literally, they're the sounds of interstellar space.

(Sound of interstellar space)

And by measuring that sound wave, we could measure the density of the plasma and we're amazed to find out that we were in interstellar space.

This is a historic milestone in the great journeys of exploration that have been undertaken by humankind.

The Very Large Baseline Array took a radio image of Voyager 1 spacecraft slightly over 11-billion miles from the Earth.

And it's a very small radio dot amongst a sea of darkness.

It is quite remarkable when you think about it, that far off now at ever increasing differences, there's this little vehicle, two of them, which were built here many years ago and launched 36 years ago.

Now, on a journey that will basically last for billions of years.

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Voyager 1, First Craft in Interstellar Space, May Have Gone Dark

The 46-year-old probe, which flew by Jupiter and Saturn in its youth and inspired earthlings with images of the planet as a “Pale Blue Dot,” hasn’t sent usable data from interstellar space in months.

By Orlando Mayorquin

When Voyager 1 launched in 1977, scientists hoped it could do what it was built to do and take up-close images of Jupiter and Saturn. It did that — and much more.

Voyager 1 discovered active volcanoes, moons and planetary rings, proving along the way that Earth and all of humanity could be squished into a single pixel in a photograph, a “ pale blue dot, ” as the astronomer Carl Sagan called it. It stretched a four-year mission into the present day, embarking on the deepest journey ever into space.

Now, it may have bid its final farewell to that faraway dot.

Voyager 1 , the farthest man-made object in space, hasn’t sent coherent data to Earth since November. NASA has been trying to diagnose what the Voyager mission’s project manager, Suzanne Dodd, called the “most serious issue” the robotic probe has faced since she took the job in 2010.

The spacecraft encountered a glitch in one of its computers that has eliminated its ability to send engineering and science data back to Earth.

The loss of Voyager 1 would cap decades of scientific breakthroughs and signal the beginning of the end for a mission that has given shape to humanity’s most distant ambition and inspired generations to look to the skies.

“Scientifically, it’s a big loss,” Ms. Dodd said. “I think — emotionally — it’s maybe even a bigger loss.”

Voyager 1 is one half of the Voyager mission. It has a twin spacecraft, Voyager 2.

Launched in 1977, they were primarily built for a four-year trip to Jupiter and Saturn , expanding on earlier flybys by the Pioneer 10 and 11 probes.

The Voyager mission capitalized on a rare alignment of the outer planets — once every 175 years — allowing the probes to visit all four.

Using the gravity of each planet, the Voyager spacecraft could swing onto the next, according to NASA .

The mission to Jupiter and Saturn was a success.

The 1980s flybys yielded several new discoveries, including new insights about the so-called great red spot on Jupiter, the rings around Saturn and the many moons of each planet.

Voyager 2 also explored Uranus and Neptune , becoming in 1989 the only spacecraft to explore all four outer planets.

Voyager 1, meanwhile, had set a course for deep space, using its camera to photograph the planets it was leaving behind along the way. Voyager 2 would later begin its own trek into deep space.

“Anybody who is interested in space is interested in the things Voyager discovered about the outer planets and their moons,” said Kate Howells, the public education specialist at the Planetary Society, an organization co-founded by Dr. Sagan to promote space exploration.

“But I think the pale blue dot was one of those things that was sort of more poetic and touching,” she added.

On Valentine’s Day 1990, Voyager 1, darting 3.7 billion miles away from the sun toward the outer reaches of the solar system, turned around and snapped a photo of Earth that Dr. Sagan and others understood to be a humbling self-portrait of humanity.

“It’s known the world over, and it does connect humanity to the stars,” Ms. Dodd said of the mission.

She added: “I’ve had many, many many people come up to me and say: ‘Wow, I love Voyager. It’s what got me excited about space. It’s what got me thinking about our place here on Earth and what that means.’”

Ms. Howells, 35, counts herself among those people.

About 10 years ago, to celebrate the beginning of her space career, Ms. Howells spent her first paycheck from the Planetary Society to get a Voyager tattoo.

Though spacecraft “all kind of look the same,” she said, more people recognize the tattoo than she anticipated.

“I think that speaks to how famous Voyager is,” she said.

The Voyagers made their mark on popular culture , inspiring a highly intelligent “Voyager 6” in “Star Trek: The Motion Picture” and references on “The X Files” and “The West Wing.”

Even as more advanced probes were launched from Earth, Voyager 1 continued to reliably enrich our understanding of space.

In 2012, it became the first man-made object to exit the heliosphere, the space around the solar system directly influenced by the sun. There is a technical debate among scientists around whether Voyager 1 has actually left the solar system, but, nonetheless, it became interstellar — traversing the space between stars.

That charted a new path for heliophysics, which looks at how the sun influences the space around it. In 2018, Voyager 2 followed its twin between the stars.

Before Voyager 1, scientific data on the sun’s gases and material came only from within the heliosphere’s confines, according to Dr. Jamie Rankin, Voyager’s deputy project scientist.

“And so now we can for the first time kind of connect the inside-out view from the outside-in,” Dr. Rankin said, “That’s a big part of it,” she added. “But the other half is simply that a lot of this material can’t be measured any other way than sending a spacecraft out there.”

Voyager 1 and 2 are the only such spacecraft. Before it went offline, Voyager 1 had been studying an anomalous disturbance in the magnetic field and plasma particles in interstellar space.

“Nothing else is getting launched to go out there,” Ms. Dodd said. “So that’s why we’re spending the time and being careful about trying to recover this spacecraft — because the science is so valuable.”

But recovery means getting under the hood of an aging spacecraft more than 15 billion miles away, equipped with the technology of yesteryear. It takes 45 hours to exchange information with the craft.

It has been repeated over the years that a smartphone has hundreds of thousands of times Voyager 1’s memory — and that the radio transmitter emits as many watts as a refrigerator lightbulb.

“There was one analogy given that is it’s like trying to figure out where your cursor is on your laptop screen when your laptop screen doesn’t work,” Ms. Dodd said.

Her team is still holding out hope, she said, especially as the tantalizing 50th launch anniversary in 2027 approaches. Voyager 1 has survived glitches before, though none as serious.

Voyager 2 is still operational, but aging. It has faced its own technical difficulties too.

NASA had already estimated that the nuclear-powered generators of both spacecrafts would likely die around 2025.

Even if the Voyager interstellar mission is near its end, the voyage still has far to go.

Voyager 1 and its twin, each 40,000 years away from the next closest star, will arguably remain on an indefinite mission.

“If Voyager should sometime in its distant future encounter beings from some other civilization in space, it bears a message,” Dr. Sagan said in a 1980 interview .

Each spacecraft carries a gold-plated phonograph record loaded with an array of sound recordings and images representing humanity’s richness, its diverse cultures and life on Earth.

“A gift across the cosmic ocean from one island of civilization to another,” Dr. Sagan said.

Orlando Mayorquin is a general assignment and breaking news reporter based in New York. More about Orlando Mayorquin

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News | October 5, 2018

Nasa voyager 2 could be nearing interstellar space.

NASA's Voyager 2 probe, currently on a journey toward interstellar space, has detected an increase in cosmic rays that originate outside our solar system.

• Voyager 1 entered interstellar space in September 2013.
• Voyager 2 is the only spacecraft to visit all four giant outer planets — Jupiter (1979 ), Saturn ( 1981), Uranus (1986 ) and Neptune (1989).
• Three other spacecraft are on interstellar trajectories: New Horizons is closing in on a close encounter with a Kuiper Belt Object more about a billion miles beyond Pluto on Jan. 1, 2019. Pioneer 10 and Pioneer 11 are no longer functioning, but will eventually travel into interstellar space.
• The Voyager Golden Record
• The Pioneer Plaque

NASA's Voyager 2 probe, currently on a journey toward interstellar space, has detected an increase in cosmic rays that originate outside our solar system. Launched in 1977, Voyager 2 is a little less than 11 billion miles (about 17.7 billion kilometers) from Earth, or more than 118 times the distance from Earth to the Sun.

Since 2007 the probe has been traveling through the outermost layer of the heliosphere -- the vast bubble around the Sun and the planets dominated by solar material and magnetic fields. Voyager scientists have been watching for the spacecraft to reach the outer boundary of the heliosphere, known as the heliopause. Once Voyager 2 exits the heliosphere, it will become the second human-made object, after Voyager 1, to enter interstellar space.

Since late August, the Cosmic Ray Subsystem instrument on Voyager 2 has measured about a 5 percent increase in the rate of cosmic rays hitting the spacecraft compared to early August. The probe's Low-Energy Charged Particle instrument has detected a similar increase in higher-energy cosmic rays.

Cosmic rays are fast-moving particles that originate outside the solar system. Some of these cosmic rays are blocked by the heliosphere, so mission planners expect that Voyager 2 will measure an increase in the rate of cosmic rays as it approaches and crosses the boundary of the heliosphere.

In May 2012, Voyager 1 experienced an increase in the rate of cosmic rays similar to what Voyager 2 is now detecting. That was about three months before Voyager 1 crossed the heliopause and entered interstellar space.

However, Voyager team members note that the increase in cosmic rays is not a definitive sign that the probe is about to cross the heliopause. Voyager 2 is in a different location in the heliosheath -- the outer region of the heliosphere -- than Voyager 1 had been, and possible differences in these locations means Voyager 2 may experience a different exit timeline than Voyager 1.

The fact that Voyager 2 may be approaching the heliopause six years after Voyager 1 is also relevant, because the heliopause moves inward and outward during the Sun's 11-year activity cycle. Solar activity refers to emissions from the Sun, including solar flares and eruptions of material called coronal mass ejections. During the 11-year solar cycle, the Sun reaches both a maximum and a minimum level of activity.

"We're seeing a change in the environment around Voyager 2, there's no doubt about that," said Voyager Project Scientist Ed Stone, based at Caltech in Pasadena. "We're going to learn a lot in the coming months, but we still don't know when we'll reach the heliopause. We're not there yet -- that's one thing I can say with confidence."

The Voyager spacecraft were built by NASA's Jet Propulsion Laboratory in Pasadena, California, which continues to operate both. JPL is a division of Caltech. The Voyager missions are a part of the NASA Heliophysics System Observatory, managed by the Heliophysics Division of the Science Mission Directorate in Washington.

For more information about the Voyager spacecraft, visit:

https://www.nasa.gov/voyager

https://voyager.jpl.nasa.gov

News Media Contacts

Calla Cofield / Jia-Rui Cook Jet Propulsion Laboratory, Pasadena, Calif. 626-808-2469 / 818-354-0724 [email protected] / [email protected]

Karen Fox NASA Headquarters, Washington 301-286-6284 [email protected]

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Voyager 1 entering interstellar space.

This artist’s concept depicts NASA’s Voyager 1 spacecraft entering interstellar space , or the space between stars. Interstellar space is dominated by the plasma, or ionized gas, that was ejected by the death of nearby giant stars millions of years ago. The environment inside our solar bubble is dominated by the plasma exhausted by our sun, known as the solar wind.

The interstellar plasma is shown with an orange glow similar to the color seen in visible-light images from NASA’s Hubble Space Telescope that show stars in the Orion nebula traveling through interstellar space.

Image credit: NASA/JPL-Caltech

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Some hope —

Finally, engineers have a clue that could help them save voyager 1, a new signal from humanity's most distant spacecraft could be the key to restoring it..

Stephen Clark - Mar 15, 2024 11:23 pm UTC

It's been four months since NASA's Voyager 1 spacecraft sent an intelligible signal back to Earth, and the problem has puzzled engineers tasked with supervising the probe exploring interstellar space.

But there's a renewed optimism among the Voyager ground team based at NASA's Jet Propulsion Laboratory in California. On March 1, engineers sent a command up to Voyager 1—more than 15 billion miles (24 billion kilometers) away from Earth—to "gently prompt" one of the spacecraft's computers to try different sequences in its software package. This was the latest step in NASA's long-distance troubleshooting to try to isolate the cause of the problem preventing Voyager 1 from transmitting coherent telemetry data.

Cracking the case

Officials suspect a piece of corrupted memory inside the Flight Data Subsystem (FDS), one of three main computers on the spacecraft, is the most likely culprit for the interruption in normal communication. Because Voyager 1 is so far away, it takes about 45 hours for engineers on the ground to know how the spacecraft reacted to their commands—the one-way light travel time is about 22.5 hours.

The FDS collects science and engineering data from the spacecraft's sensors, then combines the information into a single data package, which goes through a separate component called the Telemetry Modulation Unit to beam it back to Earth through Voyager's high-gain antenna.

Engineers are almost entirely certain the problem is in the FDS computer. The communications systems onboard Voyager 1 appear to be functioning normally, and the spacecraft is sending a steady radio tone back to Earth, but there's no usable data contained in the signal. This means engineers know Voyager 1 is alive, but they have no insight into what part of the FDS memory is causing the problem.

But Voyager 1 responded to the March 1 troubleshooting command with something different from what engineers have seen since this issue first appeared on November 14.

"The new signal was still not in the format used by Voyager 1 when the FDS is working properly, so the team wasn’t initially sure what to make of it," NASA said in an update Wednesday. "But an engineer with the agency’s Deep Space Network, which operates the radio antennas that communicate with both Voyagers and other spacecraft traveling to the Moon and beyond, was able to decode the new signal and found that it contains a readout of the entire FDS memory."

Now, engineers are meticulously comparing each bit of code from the FDS memory readout to the memory readout Voyager 1 sent back to Earth before the issue arose in November. This, they hope, will allow them to find the root of the problem. But it will probably take weeks or months for the Voyager team to take the next step. They don't want to cause more harm.

"Using that information to devise a potential solution and attempt to put it into action will take time," NASA said.

This is perhaps the most serious ailment the spacecraft has encountered since its launch in 1977. Voyager 1 flew by Jupiter and Saturn before getting a kick from Saturn's gravity to speed into the outer solar system. In 2012, Voyager 1 entered interstellar space when it crossed the heliopause, where the solar wind, the stream of particles emanating from the Sun, push against a so-called galactic wind, the particles that populate the void between the stars.

Engineers have kept Voyager 1 and its twin, Voyager 2, alive for more than 46 years , overcoming technical problems that have doomed other space missions. Both probes face waning power from their nuclear batteries, and there are concerns about their thrusters aging and fuel lines becoming clogged, among other things. But each time there is a problem, ground teams have come up with a trick to keep the Voyagers going, often referencing binders of fraying blueprints and engineering documents from the spacecraft's design and construction nearly 50 years ago.

Suzanne Dodd, NASA's project manager for Voyager 1 and its twin, Voyager 2, recently told Ars that engineers would need to pull off their "biggest miracle" to restore Voyager 1 to normal operations. Now, Voyager 1's voice from the sky has provided engineers with a clue that could help them realize this miracle.

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The Voyager spacecraft will probably last a billion years, says a scientist on the mission for nearly 5 decades

• Alan Cummings has worked on the Voyager mission for over 50 years.
• Since their launch, the two Voyager spacecraft have made breakthrough discoveries that keep Cummings engaged.
• Cummings thinks they will continue traveling for a billion years.

The twin Voyager spacecraft launched almost five decades ago, and there's no reason they shouldn't keep going for a billion years, one of its scientists, Alan Cummings told Business Insider.

Cummings started working on the Voyager mission when he was a graduate student at Caltech in 1973, about four years before the two spacecraft launched.

Now a senior research scientist at Caltech, Cummings has seen the program dwindle from over 300 people to fewer than a dozen.

Voyagers 1 and 2 have traveled over 10 billion miles into space, further than any human-made object. Cummings said being a part of this historic mission for so many decades has been the backbone of his career.

"The Hubble Telescope is a great mission," he said. " JWST is a great mission, but I think Voyager's in that kind of category."

Voyagers' endurance

The Voyager mission has been gathering groundbreaking data and photos since the beginning.

The first time Cummings saw Jupiter's moon Io in 1979, for example, he thought it was a joke. "It looked like a poorly made pizza," he said.

Its colorful, volcano-covered surface looked so different from Earth's gray, pockmarked moon . "This can't be real," he said, "and it was real."

The Voyagers offered us a new perspective on our outer solar system, unlike anything we could have imagined.

They discovered Saturn wasn't the only planet with rings — Jupiter has them too. They revealed new moons around Jupiter and Saturn.

In total, the two spacecraft snapped 67,000 images of our solar system, the final of which was the "pale blue dot" photo made famous by Carl Sagan who said:

"To my mind, there is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world."

"It rewrote the textbooks," Cummings said of the mission.

Both Voyagers were initially planned as five-year missions, but Cummings said, from the beginning, he expected the spacecraft to last at least 30 to 40 years.

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"A remarkable engineering team has kept this thing going," Cummings said.

Now, as the two spacecraft approach their 50th anniversaries, they're running low on fuel.

Engineers have had to shut down different instruments to keep them going and the data coming in.

Cummings said once the Voyagers lose power and communication, they'll continue traveling. "I think it's going to go for a billion years," he said. "There's nothing to stop it."

Joining Voyager

If it weren't for an unfortunate accident, Cummings may never have joined the Voyager mission.

Before Voyager, Cummings was part of an experiment to measure cosmic rays using a balloon.

For several summers, he had released the balloon from northern Manitoba, Canada.

But during its final flight, the balloon didn't descend as expected and ended up over Russia, instead.

By the time Cummings got to Russia, the instrument was destroyed.

"It was very fortunate for me," he said, because he was able to then join the Voyager mission.

He put his cosmic ray experience to use, working on telescopes for the mission's experiments.

"I have my little initials scratched on one of those" telescopes he said, "so I guess I'm going to be immortal."

Interstellar space

Cummings has worked on other projects over the decades, but Voyagers' continual transmission of new data has kept him excited and involved.

"There's always some new phenomenon that you see," he said.

In fact, Voyager's data has become increasingly more interesting to Cummings in recent years because the two spacecraft are now in interstellar space , the region of space beyond our sun's influence.

After passing by the four giant planets of Jupiter, Saturn, Neptune, and Uranus, many of the instruments were still in working order. So, the spacecraft transitioned to an interstellar mission.

In 2012, Voyager 1 became the first human-made spacecraft to enter interstellar space and Voyager 2 followed six years later.

"That is really what I was most interested in anyway," Cummings said, since cosmic rays are his field of expertise and in interstellar space, those rays aren't disrupted by the sun, Earth, and other obstructions in our solar system.

Voyager is "making its most interesting measurements in some ways right now," he said.

Currently, Voyager 1 is having issues with one of its onboard computers that could compromise the mission.

Cummings hopes the Voyagers can hang on a little longer, especially since interstellar space is a long way off for any other spacecraft.

Watch: NASA released this 5-year time-lapse of Mars from its Curiosity rover — and the footage looks amazing

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News | November 4, 2019

Voyager 2 illuminates boundary of interstellar space.

One year ago, on Nov. 5, 2018, NASA's Voyager 2 became only the second spacecraft in history to leave the heliosphere - the protective bubble of particles and magnetic fields created by our Sun. At a distance of about 11 billion miles (18 billion kilometers) from Earth - well beyond the orbit of Pluto - Voyager 2 had entered interstellar space, or the region between stars. Today, five new research papers in the journal Nature Astronomy describe what scientists observed during and since Voyager 2's historic crossing.

Each paper details the findings from one of Voyager 2's five operating science instruments: a magnetic field sensor, two instruments to detect energetic particles in different energy ranges and two instruments for studying plasma (a gas composed of charged particles). Taken together, the findings help paint a picture of this cosmic shoreline, where the environment created by our Sun ends and the vast ocean of interstellar space begins.

The Sun's heliosphere is like a ship sailing through interstellar space. Both the heliosphere and interstellar space are filled with plasma, a gas that has had some of its atoms stripped of their electrons. The plasma inside the heliosphere is hot and sparse, while the plasma in interstellar space is colder and denser. The space between stars also contains cosmic rays, or particles accelerated by exploding stars. Voyager 1 discovered that the heliosphere protects Earth and the other planets from more than 70% of that radiation.

When Voyager 2 exited the heliosphere last year , scientists announced that its two energetic particle detectors noticed dramatic changes: The rate of heliospheric particles detected by the instruments plummeted, while the rate of cosmic rays (which typically have higher energies than the heliospheric particles) increased dramatically and remained high. The changes confirmed that the probe had entered a new region of space.

Before Voyager 1 reached the edge of the heliosphere in 2012, scientists didn't know exactly how far this boundary was from the Sun. The two probes exited the heliosphere at different locations and also at different times in the constantly repeating, approximately 11-year solar cycle, over the course of which the Sun goes through a period of high and low activity. Scientists expected that the edge of the heliosphere, called the heliopause, can move as the Sun's activity changes, sort of like a lung expanding and contracting with breath. This was consistent with the fact that the two probes encountered the heliopause at different distances from the Sun.

The new papers now confirm that Voyager 2 is not yet in undisturbed interstellar space: Like its twin, Voyager 1, Voyager 2 appears to be in a perturbed transitional region just beyond the heliosphere.

"The Voyager probes are showing us how our Sun interacts with the stuff that fills most of the space between stars in the Milky Way galaxy," said Ed Stone, project scientist for Voyager and a professor of physics at Caltech. "Without this new data from Voyager 2, we wouldn't know if what we were seeing with Voyager 1 was characteristic of the entire heliosphere or specific just to the location and time when it crossed."

Pushing Through Plasma

The two Voyager spacecraft have now confirmed that the plasma in local interstellar space is significantly denser than the plasma inside the heliosphere, as scientists expected. Voyager 2 has now also measured the temperature of the plasma in nearby interstellar space and confirmed it is colder than the plasma inside the heliosphere.

In 2012, Voyager 1 observed a slightly higher-than-expected plasma density just outside the heliosphere, indicating that the plasma is being somewhat compressed. Voyager 2 observed that the plasma outside the heliosphere is slightly warmer than expected, which could also indicate it is being compressed. (The plasma outside is still colder than the plasma inside.) Voyager 2 also observed a slight increase in plasma density just before it exited the heliosphere, indicating that the plasma is compressed around the inside edge of the bubble. But scientists don't yet fully understand what is causing the compression on either side.

Leaking Particles

If the heliosphere is like a ship sailing through interstellar space, it appears the hull is somewhat leaky. One of Voyager's particle instruments showed that a trickle of particles from inside the heliosphere is slipping through the boundary and into interstellar space. Voyager 1 exited close to the very "front" of the heliosphere, relative to the bubble's movement through space. Voyager 2, on the other hand, is located closer to the flank, and this region appears to be more porous than the region where Voyager 1 is located.

Magnetic Field Mystery

An observation by Voyager 2's magnetic field instrument confirms a surprising result from Voyager 1: The magnetic field in the region just beyond the heliopause is parallel to the magnetic field inside the heliosphere. With Voyager 1, scientists had only one sample of these magnetic fields and couldn't say for sure whether the apparent alignment was characteristic of the entire exterior region or just a coincidence. Voyager 2's magnetometer observations confirm the Voyager 1 finding and indicate that the two fields align, according to Stone.

The Voyager probes launched in 1977, and both flew by Jupiter and Saturn. Voyager 2 changed course at Saturn in order to fly by Uranus and Neptune, performing the only close flybys of those planets in history. The Voyager probes completed their Grand Tour of the planets and began their Interstellar Mission to reach the heliopause in 1989. Voyager 1, the faster of the two probes, is currently over 13.6 billion miles (22 billion kilometers) from the Sun, while Voyager 2 is 11.3 billion miles (18.2 billion kilometers) from the Sun. It takes light about 16.5 hours to travel from Voyager 2 to Earth. By comparison, light traveling from the Sun takes about eight minutes to reach Earth.

More information about Voyager is available at the following site:

https://voyager.jpl.nasa.gov/

News Media Contact

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

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NASA's Voyager 1 spacecraft is talking nonsense. Its friends on Earth are worried

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This artist's impression shows one of the Voyager spacecraft moving through the darkness of space. NASA/JPL-Caltech hide caption

This artist's impression shows one of the Voyager spacecraft moving through the darkness of space.

The last time Stamatios "Tom" Krimigis saw the Voyager 1 space probe in person, it was the summer of 1977, just before it launched from Cape Canaveral, Florida.

Now Voyager 1 is over 15 billion miles away, beyond what many consider to be the edge of the solar system. Yet the on-board instrument Krimigis is in charge of is still going strong.

"I am the most surprised person in the world," says Krimigis — after all, the spacecraft's original mission to Jupiter and Saturn was only supposed to last about four years.

These days, though, he's also feeling another emotion when he thinks of Voyager 1.

"Frankly, I'm very worried," he says.

Ever since mid-November, the Voyager 1 spacecraft has been sending messages back to Earth that don't make any sense. It's as if the aging spacecraft has suffered some kind of stroke that's interfering with its ability to speak.

"It basically stopped talking to us in a coherent manner," says Suzanne Dodd of NASA's Jet Propulsion Laboratory, who has been the project manager for the Voyager interstellar mission since 2010. "It's a serious problem."

Instead of sending messages home in binary code, Voyager 1 is now just sending back alternating 1s and 0s. Dodd's team has tried the usual tricks to reset things — with no luck.

It looks like there's a problem with the onboard computer that takes data and packages it up to send back home. All of this computer technology is primitive compared to, say, the key fob that unlocks your car, says Dodd.

"The button you press to open the door of your car, that has more compute power than the Voyager spacecrafts do," she says. "It's remarkable that they keep flying, and that they've flown for 46-plus years."

Each of the Voyager probes carries an American flag and a copy of a golden record that can play greetings in many languages. NASA/JPL-Caltech hide caption

Each of the Voyager probes carries an American flag and a copy of a golden record that can play greetings in many languages.

Voyager 1 and its twin, Voyager 2, have outlasted many of those who designed and built them. So to try to fix Voyager 1's current woes, the dozen or so people on Dodd's team have had to pore over yellowed documents and old mimeographs.

"They're doing a lot of work to try and get into the heads of the original developers and figure out why they designed something the way they did and what we could possibly try that might give us some answers to what's going wrong with the spacecraft," says Dodd.

She says that they do have a list of possible fixes. As time goes on, they'll likely start sending commands to Voyager 1 that are more bold and risky.

"The things that we will do going forward are probably more challenging in the sense that you can't tell exactly if it's going to execute correctly — or if you're going to maybe do something you didn't want to do, inadvertently," says Dodd.

Linda Spilker , who serves as the Voyager mission's project scientist at NASA's Jet Propulsion Laboratory, says that when she comes to work she sees "all of these circuit diagrams up on the wall with sticky notes attached. And these people are just having a great time trying to troubleshoot, you know, the 60's and 70's technology."

"I'm cautiously optimistic," she says. "There's a lot of creativity there."

Still, this is a painstaking process that could take weeks, or even months. Voyager 1 is so distant, it takes almost a whole day for a signal to travel out there, and then a whole day for its response to return.

"We'll keep trying," says Dodd, "and it won't be quick."

In the meantime, Voyager's 1 discombobulation is a bummer for researchers like Stella Ocker , an astronomer with Caltech and the Carnegie Observatories

"We haven't been getting science data since this anomaly started," says Ocker, "and what that means is that we don't know what the environment that the spacecraft is traveling through looks like."

After 35 Years, Voyager Nears Edge Of Solar System

That interstellar environment isn't just empty darkness, she says. It contains stuff like gas, dust, and cosmic rays. Only the twin Voyager probes are far out enough to sample this cosmic stew.

"The science that I'm really interested in doing is actually only possible with Voyager 1," says Ocker, because Voyager 2 — despite being generally healthy for its advanced age — can't take the particular measurements she needs for her research.

Even if NASA's experts and consultants somehow come up with a miraculous plan that can get Voyager 1 back to normal, its time is running out.

The two Voyager probes are powered by plutonium, but that power system will eventually run out of juice. Mission managers have turned off heaters and taken other measures to conserve power and extend the Voyager probes' lifespan.

"My motto for a long time was 50 years or bust," says Krimigis with a laugh, "but we're sort of approaching that."

In a couple of years, the ebbing power supply will force managers to start turning off science instruments, one by one. The very last instrument might keep going until around 2030 or so.

When the power runs out and the probes are lifeless, Krimigis says both of these legendary space probes will basically become "space junk."

"It pains me to say that," he says. While Krimigis has participated in space missions to every planet, he says the Voyager program has a special place in his heart.

Spilker points out that each spacecraft will keep moving outward, carrying its copy of a golden record that has recorded greetings in many languages, along with the sounds of Earth.

"The science mission will end. But a part of Voyager and a part of us will continue on in the space between the stars," says Spilker, noting that the golden records "may even outlast humanity as we know it."

Krimigis, though, doubts that any alien will ever stumble across a Voyager probe and have a listen.

"Space is empty," he says, "and the probability of Voyager ever running into a planet is probably slim to none."

It will take about 40,000 years for Voyager 1 to approach another star; it will come within 1.7 light years of what NASA calls "an obscure star in the constellation Ursa Minor" — also known as the Little Dipper.

If NASA greenlights this interstellar mission, it could last 100 years

Knowing that the Voyager probes are running out of time, scientists have been drawing up plans for a new mission that, if funded and launched by NASA, would send another probe even farther out into the space between stars.

"If it happens, it would launch in the 2030s," says Ocker, "and it would reach twice as far as Voyager 1 in just 50 years."

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NASA Engineers Make Progress Toward Understanding Voyager 1 Issue

Since November 2023, NASA’s Voyager 1 spacecraft has been sending a steady radio signal to Earth, but the signal does not contain usable data. The source of the issue appears to be with one of three onboard computers, the flight data subsystem (FDS), which is responsible for packaging the science and engineering data before it’s sent to Earth by the telemetry modulation unit.

On March 3, the Voyager mission team saw activity from one section of the FDS that differed from the rest of the computer’s unreadable data stream. The new signal was still not in the format used by Voyager 1 when the FDS is working properly, so the team wasn’t initially sure what to make of it. But an engineer with the agency’s Deep Space Network, which operates the radio antennas that communicate with both Voyagers and other spacecraft traveling to the Moon and beyond, was able to decode the new signal and found that it contains a readout of the entire FDS memory.

The FDS memory includes its code, or instructions for what to do, as well as variables, or values used in the code that can change based on commands or the spacecraft’s status. It also contains science or engineering data for downlink. The team will compare this readout to the one that came down before the issue arose and look for discrepancies in the code and the variables to potentially find the source of the ongoing issue.

This new signal resulted from a command sent to Voyager 1 on March 1. Called a “poke” by the team, the command is meant to gently prompt the FDS to try different sequences in its software package in case the issue could be resolved by going around a corrupted section.

Because Voyager 1 is more than 15 billion miles (24 billion kilometers) from Earth, it takes 22.5 hours for a radio signal to reach the spacecraft and another 22.5 hours for the probe’s response to reach antennas on the ground. So the team received the results of the command on March 3. On March 7, engineers began working to decode the data, and on March 10, they determined that it contains a memory readout.

The team is analyzing the readout. Using that information to devise a potential solution and attempt to put it into action will take time.

News Media Contact Calla  Cofield Jet Propulsion Laboratory, Pasadena, Calif. 626-808-2469 calla.e. cofield @jpl.nasa.gov

NASA finds clue while solving Voyager 1's communication breakdown case

An outlier signal has brought ground control closer to decoding the troubling problem.

NASA engineers are a step closer to solving the communication problem that left the Voyager 1 spacecraft, which presently sits outside the solar system, unable to send usable data back to Earth.

In 2012, Voyager 1 became the first human-made object to leave the solar system and enter interstellar space . For 11 years following this achievement, the spacecraft dutifully sent data to ground control. This was data that detailed how space works beyond the influence of the sun. In Nov. 2023, however, Voyager 1's communications with ground operators stopped making sense. 

To be clear, however, Voyager 2 , which followed its spacecraft sibling out of the solar system in 2018, is still operational and communicating with Earth.

"Effectively, the call between the spacecraft and the Earth was still connected, but Voyager's 'voice' was replaced with a monotonous dial tone," Voyager 1's engineering team previously told Space.com .

The source of the issue appears to be one of Voyager 1's three onboard computers: The flight data subsystem (FDS). This computer, NASA says , is responsible for packaging science and engineering data before it's sent to Earth by the spacecraft's telemetry modulation unit.

Related: NASA's Voyager 1 glitch has scientists sad yet hopeful: 'Voyager 2 is still going strong'

The positive step towards solving communications issues between ground control and Voyager 1 came on March 3 when the Voyager mission team detected activity from one section of the FDS that was different from the rest of the computer’s garbled data stream.

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Voyager 1's messaging to Earth comes in the form of 1s and 0s, a computer language called binary code — but since the end of last year, this code has carried no meaning. Even the newly detected signal is still not in the correct format Voyager 1 should be using when FDS is functioning as designed, meaning the operating team was initially not quite sure what to make of it.

This changed, however, when an engineer at NASA's Deep Space Network , which is tasked with operating radio antennas that communicate with Voyager 1 and its interstellar sibling Voyager 2, as well as other NASA spacecraft closer to home, got a look at the code. The unnamed engineer was able to decode the outlier signal, discovering that it contained a readout of the FDS' entire memory.

Encoded with the FDS memory are performance instructions and code values that can change either if the spacecraft's status changes or if commanded to do so. Science and engineering data to be sent back to Earth are also locked up in the memory. 

The team will now compare this new signal, which occurred because of a prompt, or "poke," from mission control, to data that was sent back to Earth just before Voyager 1 started spouting binary nonsense. Finding discrepancies between regular Voyager 1 data and this poke-prompted signal will help the crew hunt for the source of the issue. The idea of the poke was to prompt FDS to try using different sequences in its software package and determine if the communication issue could be resolved by navigating around a corrupted or damaged section.

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

—  NASA's interstellar Voyager probes get software updates beamed from 12 billion miles away

—  NASA Voyager 2 spacecraft extends its interstellar science mission for 3 more years

Voyager 1 is currently around 15 billion miles (24 billion kilometers) from Earth, meaning that solving communication issues can be a painstaking process. It takes 22.5 hours to receive a radio signal from Voyager 1, then another 22.5 hours to receive a response via the Deep Space Network's antennas.

That means the results of NASA's poke were received on March 3, and on March 7 engineers started working to decode this signal. Three days later they determined the signal contains an FDS memory readout.

NASA scientists and engineers will continue to analyze this readout to restore communication with the pioneering space mission that extended humanity's reach beyond the solar system.

Join our Space Forums to keep talking space on the latest missions, night sky and more! And if you have a news tip, correction or comment, let us know at: [email protected].

Robert Lea is a science journalist in the U.K. whose articles have been published in Physics World, New Scientist, Astronomy Magazine, All About Space, Newsweek and ZME Science. He also writes about science communication for Elsevier and the European Journal of Physics. Rob holds a bachelor of science degree in physics and astronomy from the U.K.’s Open University. Follow him on Twitter @sciencef1rst.

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Voyager 1 is 15 billion miles from home and broken. Here's how NASA is trying to fix it.

A scrambled computer signal may be the key that helps NASA engineers resume data transmission from the distant Voyager 1, a spacecraft that was launched in 1977 and now, 15 billion miles from home, is the farthest a human-made object has traveled from Earth.

Voyager 1 – and its sister craft, Voyager 2 – are robotic space probes that became the first spacecraft to leave our solar system and plunge into interstellar space, 11 billion miles from the sun.

They were designed to last five years , but have become the longest-operating spacecraft in history. Both carry gold-plated copper discs containing sounds and images from Earth, contents that were chosen by a team headed by celebrity astronomer Carl Sagan .

Voyager 2, now 12.7 billion miles from Earth, is functioning normally. However, a computer problem aboard Voyager 1 on Nov. 14, 2023, corrupted the stream of science and engineering data the craft is sending to Earth, making it unreadable , arstechnica.com reported.

Voyager 1 can receive communications from Earth. It is still transmitting, but its returning signals have been replaced “with a monotonous dial tone ,” according to space.com.

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What's the problem with Voyager 1?

NASA and Jet Propulsion Laboratory engineers traced the problem to one of Voyager’s three onboard computers, one called a Flight Data System. The system collects information, including:

◾ Data from science instruments that monitor cosmic rays, solar wind particles, the sun's magnetic field, and other phenomena.

◾ Engineering data on spacecraft operating systems.

The Flight Data System gives that information to the spacecraft’s Telemetry Modulation Unit. The The unit converts the data to binary code – consisting of zeros and ones, the simplest form of computer code – then transmits that code to Earth, using Voyager's 12-foot antenna dish.

The data is received by NASA's Deep Space Network , giant 112-foot radio antennas placed around the world. The network handles space communications from several missions.

In November, the Telemetry Modulation Unit transmissions became a repeating pattern of zeros and ones " as if it were stuck ," NASA said.

Engineers restarted the Flight Data System in December, but that failed to fix the problem.

Voyager 1 is far away – and it's getting old

Voyager 1 has been in space for more than 46 years. Attempts to fix problems aboard the spacecraft often mean "consulting original, decades-old documents written by engineers who didn’t anticipate the issues that are arising today," NASA says. 

Engineers have consulted archived documents to find solutions to other Voyager problems in the past, wired.com says.

Engineers need time to understand how new commands will affect the spacecraft and to avoid unintended consequences. It's a complicated, time-consuming process.

A long time lag makes solving the problem more difficult. Voyager is moving at about 38,000 mph. It takes 22.5 hours for an Earth radio signal to reach Voyager and another 22.5 hours for the spacecraft’s reply to reach antenna networks on Earth.

That means engineers must wait 45 hours to get a response and learn if a command has been successful.

What was the key computer signal?

The key signal was received after engineers "poked" the spacecraft.

◾ March 1: Teams send a command known as a “poke” to Voyager. In essence, the poke tells the Flight Data System to try different sequences in its software program, in the hope a corrupted portion can be found and bypassed.

◾ March 3: Engineers receive a new signal from Voyager that is different from both the unreadable dial tone and the spacecraft’s original transmission stream.

◾ March 7: Engineers begin decoding the signal.

◾ March 10: A Deep Space Network engineer finishes decoding the new signal and finds it contains a readout of the spacecraft’s entire Flight Data System memory. That includes instructions for the spacecraft when it receives commands or when its operational status changes. 

The memory also contains science or engineering data for downlink, NASA says.

What happens next?

Engineers will compare the readout to those transmitted before the problem started. They hope to find differences that will help diagnose the problem.

Voyager 2 was launched first on Aug. 20, 1977. Voyager 1 was launched Sept. 5, 1977. It was put on a faster, shorter trajectory, which took it to interstellar space ahead of Voyager 2.

The Voyagers are the only spacecraft in the interstellar void. NASA's New Horizons probe , launched Jan. 19, 2006, flew past Pluto in 2015 and is expected to enter interstellar space in the 2040s.