what is voyager 1 mission

Voyager, NASA’s Longest-Lived Mission, Logs 45 Years in Space

This archival image taken at NASA’s Jet Propulsion Laboratory on March 23, 1977, shows engineers preparing the Voyager 2 spacecraft ahead of its launch later that year.

Launched in 1977, the twin Voyager probes are NASA’s longest-operating mission and the only spacecraft ever to explore interstellar space.

NASA’s twin Voyager probes have become, in some ways, time capsules of their era: They each carry an eight-track tape player for recording data, they have about 3 million times less memory than modern cellphones, and they transmit data about 38,000 times slower than a 5G internet connection.

Yet the Voyagers remain on the cutting edge of space exploration. Managed and operated by NASA’s Jet Propulsion Laboratory in Southern California, they are the only probes to ever explore interstellar space – the galactic ocean that our Sun and its planets travel through.

The Sun and the planets reside in the heliosphere, a protective bubble created by the Sun’s magnetic field and the outward flow of solar wind (charged particles from the Sun). Researchers – some of them younger than the two distant spacecraft – are combining Voyager’s observations with data from newer missions to get a more complete picture of our Sun and how the heliosphere interacts with interstellar space.

NASA’s Solar System Interactive lets users see where the Voyagers are right now relative to the planets, the Sun, and other spacecraft. View it yourself here . Credit: NASA/JPL-Caltech

“The heliophysics mission fleet provides invaluable insights into our Sun, from understanding the corona or the outermost part of the Sun’s atmosphere, to examining the Sun’s impacts throughout the solar system, including here on Earth, in our atmosphere, and on into interstellar space,” said Nicola Fox, director of the Heliophysics Division at NASA Headquarters in Washington. “Over the last 45 years, the Voyager missions have been integral in providing this knowledge and have helped change our understanding of the Sun and its influence in ways no other spacecraft can.”

The Voyagers are also ambassadors, each carrying a golden record containing images of life on Earth, diagrams of basic scientific principles, and audio that includes sounds from nature, greetings in multiple languages, and music. The gold-coated records serve as a cosmic “message in a bottle” for anyone who might encounter the space probes. At the rate gold decays in space and is eroded by cosmic radiation, the records will last more than a billion years.

45 Years of Voyager I and II

Launched in 1977, NASA’s twin Voyager spacecraft inspired the world with pioneering visits to Jupiter, Saturn, Uranus, and Neptune. Their journey continues 45 years later as both probes explore interstellar space, the region outside the protective heliosphere created by our Sun. Researchers – some younger than the spacecraft – are now using Voyager data to solve mysteries of our solar system and beyond.

This archival photo shows engineers working on vibration acoustics and pyro shock testing of NASA’s Voyager on Nov. 18, 1976. Credit: NASA/JPL-Caltech

NASA’s Voyager 1 acquired this image of a volcanic explosion on Io on March 4, 1979, about 11 hours before the spacecraft’s closest approach to the moon of Jupiter.

Neptune’s green-blue atmosphere was shown in greater detail than ever before in this image from NASA’s Voyager 2 as the spacecraft rapidly approached its encounter with the giant planet in August 1989.

This updated version of the iconic "Pale Blue Dot" image taken by the Voyager 1 spacecraft uses modern image-processing software and techniques to revisit the well-known Voyager view while attempting to respect the original data and intent of those who planned the images.

This illustrated graphic was made to mark Voyager 1’s entry into interstellar space in 2012. It puts solar system distances in perspective, with the scale bar in astronomical units and each set distance beyond 1 AU (the average distance between the Sun and Earth) representing 10 times the previous distance.

This graphic highlights some of the Voyager mission’s key accomplishments. Credit: NASA/JPL-Caltech Full image details

This graphic provides some of the mission’s key statistics from 2018, when NASA’s Voyager 2 probe exited the heliosphere. Credit: NASA/JPL-Caltech Full image details

Beyond Expectations

Voyager 2 launched on Aug. 20, 1977, quickly followed by Voyager 1 on Sept. 5. Both probes traveled to Jupiter and Saturn, with Voyager 1 moving faster and reaching them first. Together, the probes unveiled much about the solar system’s two largest planets and their moons. Voyager 2 also became the first and only spacecraft to fly close to Uranus (in 1986) and Neptune (in 1989), offering humanity remarkable views of – and insights into – these distant worlds.

While Voyager 2 was conducting these flybys, Voyager 1 headed toward the boundary of the heliosphere. Upon exiting it in 2012 , Voyager 1 discovered that the heliosphere blocks 70% of cosmic rays, or energetic particles created by exploding stars. Voyager 2, after completing its planetary explorations, continued to the heliosphere boundary, exiting in 2018 . The twin spacecraft’s combined data from this region has challenged previous theories about the exact shape of the heliosphere.

Voyager 1 and 2 have accomplished a lot since they launched in 1977. This infographic highlights the mission’s major milestones, including visiting the four outer planets and exiting the heliosphere, or the protective bubble of magnetic fields and particles created by the Sun.

“Today, as both Voyagers explore interstellar space, they are providing humanity with observations of uncharted territory,” said Linda Spilker, Voyager’s deputy project scientist at JPL. “This is the first time we’ve been able to directly study how a star, our Sun, interacts with the particles and magnetic fields outside our heliosphere, helping scientists understand the local neighborhood between the stars, upending some of the theories about this region, and providing key information for future missions.”

The Long Journey

Over the years, the Voyager team has grown accustomed to surmounting challenges that come with operating such mature spacecraft, sometimes calling upon retired colleagues for their expertise or digging through documents written decades ago.

Each Voyager is powered by a radioisotope thermoelectric generator containing plutonium, which gives off heat that is converted to electricity. As the plutonium decays, the heat output decreases and the Voyagers lose electricity. To compensate , the team turned off all nonessential systems and some once considered essential, including heaters that protect the still-operating instruments from the frigid temperatures of space. All five of the instruments that have had their heaters turned off since 2019 are still working, despite being well below the lowest temperatures they were ever tested at.

Get the Latest JPL News

Recently, Voyager 1 began experiencing an issue that caused status information about one of its onboard systems to become garbled. Despite this, the system and spacecraft otherwise continue to operate normally, suggesting the problem is with the production of the status data, not the system itself. The probe is still sending back science observations while the engineering team tries to fix the problem or find a way to work around it.

“The Voyagers have continued to make amazing discoveries, inspiring a new generation of scientists and engineers,” said Suzanne Dodd, project manager for Voyager at JPL. “We don’t know how long the mission will continue, but we can be sure that the spacecraft will provide even more scientific surprises as they travel farther away from the Earth.”

More About the Mission

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

News Media Contact

Calla Cofield

Jet Propulsion Laboratory, Pasadena, Calif.

626-808-2469

[email protected]

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The Voyager missions

Highlights Voyager 1 and Voyager 2 launched in 1977 and made a grand tour of the solar system's outer planets. They are the only functioning spacecraft in interstellar space, and they are still sending back measurements of the interstellar medium. Each spacecraft carries a copy of the golden record, a missive from Earth to any alien lifeforms that may find the probes in the future.

What are the Voyager missions?

The Voyager program consists of two spacecraft: Voyager 1 and Voyager 2. Voyager 2 was actually launched first, in August 1977, but Voyager 1 was sent on a faster trajectory when it launched about two weeks later. They are the only two functioning spacecraft currently in interstellar space, beyond the environment controlled by the sun.

Voyager 2’s path took it past Jupiter in 1979, Saturn in 1981, Uranus in 1985, and Neptune in 1989. It is the only spacecraft to have visited Uranus or Neptune, and has provided much of the information that we use to characterize them now.

Because of its higher speed and more direct trajectory, Voyager 1 overtook Voyager 2 just a few months after they launched. It visited Jupiter in 1979 and Saturn in 1980. It overtook Pioneer 10 — the only other spacecraft in interstellar space thus far — in 1998 and is now the most distant artificial object from Earth.

How the Voyagers work

The two spacecraft are identical, each with a radio dish 3.7 meters (12 feet) across to transmit data back to Earth and a set of 16 thrusters to control their orientations and point their dishes toward Earth. The thrusters run on hydrazine fuel, but the electronic components of each spacecraft are powered by thermoelectric generators that run on plutonium. Each carries 11 scientific instruments, about half of which were designed just for observing planets and have now been shut off. The instruments that are now off include several cameras and spectrometers to examine the planets, as well as two radio-based experiments. Voyager 2 now has five functioning instruments: a magnetometer, a spectrometer designed to investigate plasmas, an instrument to measure low-energy charged particles and one for cosmic rays, and one that measures plasma waves. Voyager 1 only has four of those, as its plasma spectrometer is broken.

Jupiter findings

Over the course of their grand tours of the solar system, the Voyagers took tens of thousands of images and measurements that significantly changed our understanding of the outer planets.

At Jupiter, they gave us our first detailed ideas of how the planet’s atmosphere moves and evolves, showing that the Great Red Spot was a counter-clockwise rotating storm that interacted with other, smaller storms. They were also the first missions to spot a faint, dusty ring around Jupiter. Finally, they observed some of Jupiter’s moons, discovering Io’s volcanism, finding the linear features on Europa that were among the first hints that it might have an ocean beneath its surface, and granting Ganymede the title of largest moon in the solar system, a superlative that was previously thought to belong to Saturn’s moon Titan.

Saturn findings

Next, each spacecraft flew past Saturn, where they measured the composition and structure of Saturn’s atmosphere , and Voyager 1 also peered into Titan’s thick haze. Its observations led to the idea that Titan might have liquid hydrocarbons on its surface, a hypothesis that has since been verified by other missions. When the two missions observed Saturn’s rings, they found the gaps and waves that are well-known today. Voyager 1 also spotted three previously-unknown moons orbiting Saturn: Atlas, Prometheus, and Pandora.

Uranus and Neptune findings

After this, Voyager 1 headed out of the solar system, while Voyager 2 headed toward Uranus . There, it found 11 previously-unknown moons and two previously-unknown rings. Many of the phenomena it observed on Uranus remained unexplained, such as its unusual magnetic field and an unexpected lack of major temperature changes at different latitudes.

Voyager 2’s final stop, 12 years after it left Earth, was Neptune. When it arrived , it continued its streak of finding new moons with another haul of 6 small satellites, as well as finding rings around Neptune. As it did at Uranus, it observed the planet’s composition and magnetic field. It also found volcanic vents on Neptune’s huge moon Triton before it joined Voyager 1 on the way to interstellar space.

Interstellar space

Interstellar space begins at the heliopause, where the solar wind – a flow of charged particles released by the sun – is too weak to continue pushing against the interstellar medium, and the pressure from the two balances out. Voyager 1 officially entered interstellar space in August 2012, and Voyager 2 joined it  in November 2018.

These exits were instrumental in enabling astronomers to determine where exactly the edge of interstellar space is, something that’s difficult to measure from within the solar system. They showed that interstellar space begins just over 18 billion kilometers (about 11 billion miles) from the sun. The spacecraft continue to send back data on the structure of the interstellar medium.

After its planetary encounters, Voyager 1 took the iconic “Pale Blue Dot” image , showing Earth from about 6 billion kilometers (3.7 billion miles) away. As of 2021 , Voyager 1 is about 155 astronomical units (14.4 billion miles) from Earth, and Voyager 2 is nearly 129 astronomical units (12 billion miles) away.

The golden records

Each Voyager spacecraft has a golden phonograph record affixed to its side, intended as time capsules from Earth to any extraterrestrial life that might find the probes sometime in the distant future. They are inscribed with a message from Jimmy Carter, the U.S. President at the time of launch, which reads: “This is a present from a small, distant world, a token of our sounds, our science, our images, our music, our thoughts and our feelings. We are attempting to survive our time so we may live into yours.”

The covers of the records have several images inscribed, including visual instructions on how to play them, a map of our solar system’s location with respect to a set of 14 pulsars, and a drawing of a hydrogen atom. They are plated with uranium – its rate of decay will allow any future discoverers of either of the records to calculate when they were created.

The records’ contents were selected by a committee chaired by Carl Sagan. Each contains 115 images, including scientific diagrams of the solar system and its planets, the flora and fauna of Earth, and examples of human culture. There are natural sounds, including breaking surf and birdsong, spoken greetings in 55 languages, an hour of brainwave recordings, and an eclectic selection of music ranging from Beethoven to Chuck Berry to a variety of folk music.

Learn more Voyager Mission Status Bulletin Archives Experience A Message From Earth - Inspired by the Voyager Golden Record Neptune, planet of wind and ice

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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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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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Hope returns —

Nasa knows what knocked voyager 1 offline, but it will take a while to fix, "engineers are optimistic they can find a way for the fds to operate normally.".

Stephen Clark - Apr 6, 2024 12:28 am UTC

Engineers have determined why NASA's Voyager 1 probe has been transmitting gibberish for nearly five months, raising hopes of recovering humanity's most distant spacecraft.

Voyager 1, traveling outbound some 15 billion miles (24 billion km) from Earth, started beaming unreadable data down to ground controllers on November 14. For nearly four months, NASA knew Voyager 1 was still alive—it continued to broadcast a steady signal—but could not decipher anything it was saying.

Confirming their hypothesis, engineers at NASA's Jet Propulsion Laboratory (JPL) in California confirmed a small portion of corrupted memory caused the problem. The faulty memory bank is located in Voyager 1's Flight Data System (FDS), one of three computers on the spacecraft. The FDS operates alongside a command-and-control central computer and another device overseeing attitude control and pointing.

The FDS duties include packaging Voyager 1's science and engineering data for relay to Earth through the craft's Telemetry Modulation Unit and radio transmitter. According to NASA, about 3 percent of the FDS memory has been corrupted, preventing the computer from carrying out normal operations.

Optimism growing

Suzanne Dodd, NASA's project manager for the twin Voyager probes, told Ars in February that this was one of the most serious problems the mission has ever faced. That is saying something because Voyager 1 and 2 are NASA's longest-lived spacecraft. They launched 16 days apart in 1977, and after flying by Jupiter and Saturn, Voyager 1 is flying farther from Earth than any spacecraft in history. Voyager 2 is trailing Voyager 1 by about 2.5 billion miles, although the probes are heading out of the Solar System in different directions.

Normally, engineers would try to diagnose a spacecraft malfunction by analyzing data it sent back to Earth. They couldn't do that in this case because Voyager 1 has been transmitting data packages manifesting a repeating pattern of ones and zeros. Still, Voyager 1's ground team identified the FDS as the likely source of the problem.

The Flight Data Subsystem was an innovation in computing when it was developed five decades ago. It was the first computer on a spacecraft to use volatile memory. Most of NASA's missions operate with redundancy, so each Voyager spacecraft launched with two FDS computers. But the backup FDS on Voyager 1 failed in 1982.

Due to the Voyagers' age, engineers had to reference paper documents, memos, and blueprints to help understand the spacecraft's design details. After months of brainstorming and planning, teams at JPL uplinked a command in early March to prompt the spacecraft to send back a readout of the FDS memory.

The command worked, and Voyager1 responded with a signal different from the code it had been transmitting since November. After several weeks of meticulous examination of the new code, engineers pinpointed the location of the bad memory.

"The team suspects that a single chip responsible for storing part of the affected portion of the FDS memory isn’t working," NASA said in an update posted Thursday. "Engineers can’t determine with certainty what caused the issue. Two possibilities are that the chip could have been hit by an energetic particle from space or that it simply may have worn out after 46 years."

Voyager 1's distance from Earth complicates the troubleshooting effort. The one-way travel time for a radio signal to reach Voyager 1 from Earth is about 22.5 hours, meaning it takes roughly 45 hours for engineers on the ground to learn how the spacecraft responded to their commands.

NASA also must use its largest communications antennas to contact Voyager 1. These 230-foot-diameter (70-meter) antennas are in high demand by many other NASA spacecraft , so the Voyager team has to compete with other missions to secure time for troubleshooting. This means it will take time to get Voyager 1 back to normal operations.

"Although it may take weeks or months, engineers are optimistic they can find a way for the FDS to operate normally without the unusable memory hardware, which would enable Voyager 1 to begin returning science and engineering data again," NASA said.

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Channel ars technica.

We finally know why NASA's Voyager 1 spacecraft stopped communicating — scientists are working on a fix

The first spacecraft to explore beyond the solar system started spouting gibberish late last year. Now, NASA knows why.

NASA engineers have discovered the cause of a communications breakdown between Earth and the interstellar explorer Voyager 1. It would appear that a small portion of corrupted memory exists in one of the spacecraft's computers. 

The glitch caused Voyager 1 to send unreadable data back to Earth, and is found in the NASA spacecraft's flight data subsystem (FDS). That's the system responsible for packaging the probe's science and engineering data before the telemetry modulation unit (TMU) and radio transmitter send it back to mission control. 

The source of the issue began to reveal itself when Voyager 1 operators sent the spacecraft a "poke" on March 3, 2024. This was intended to prompt FDS to send a full memory readout back to Earth.

The readout confirmed to the NASA team that about 3% of the FDS memory had been corrupted, and that this was preventing the computer from carrying out its normal operations.

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

Launched in 1977, Voyager 1 became the first human-made object to leave the solar system and enter interstellar space in 2012. Voyager 2 followed its spacecraft sibling out of the solar system in 2018, and is still operational and communicating well with  Earth.

After 11 years of interstellar exploration, in Nov. 2023, Voyager 1's binary code — the computer language it uses to communicate with Earth — stopped making sense. Its 0's and 1's didn't mean anything anymore.

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"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 team strongly suspects this glitch is the result of a single chip that's responsible for storing part of the affected portion of the FDS memory ceasing to work.

Currently, however, NASA can’t say for sure what exactly caused that particular issue. The chip could have been struck by a high-speed energetic particle from space or, after 46 years serving Voyager 1, it may simply have worn out.

—  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 currently sits around 15 billion miles (24 billion kilometers) from Earth, which means it takes 22.5 hours to receive a radio signal from it — and another 22.5 hours for the spacecraft to receive a response via the Deep Space Network's antennas. Solving this communication issue is thus no mean feat.

Yet, NASA scientists and engineers are optimistic they can find a way to help FDS operate normally, even without the unusable memory hardware.

Solving this issue could take weeks or even months, according to NASA — but if it is resolved, Voyager 1 should be able to resume returning science data about what lies outside 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.

Rocket Lab to launch NASA's new solar sail technology no earlier than April 24

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SpaceX launching 23 Starlink satellites from Florida this evening

• jcs Funny timing for this article, when I am streaming an old Star Trek movie. So, surely this didn't cause a 3 byte glitch removing the O, Y and A from Voyager's name buffer? Get it? Reply
• bwana4swahili It is quite amazing it has lasted this long in a space environment. Reply

bwana4swahili said: It is quite amazing it has lasted this long in a space environment.

• HankySpanky So now we know even better for next time. Perhaps a spare chipset that is not redundant but is ready to take over, stored in a protective environment. A task NASA can handle. We'll find out in 100 year or so - if humanity still exists. Reply

HankySpanky said: So now we know even better for next time. Perhaps a spare chipset that is not redundant but is ready to take over, stored in a protective environment. A task NASA can handle. We'll find out in 100 year or so - if humanity still exists.

• Classical Motion I'm afraid it might self repair. And download galactic knowledge, then decide we are a danger. And turn around. Reply

Classical Motion said: I'm afraid it might self repair. And download galactic knowledge, then decide we are a danger. And turn around.

• jcs ROFLOL! And a hot bald chick delivering the bad news! Reply
• View All 8 Comments

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Voyager 1 & 2

• Launched on September 5, 1977
• Surveyed the Jupiter and Saturn systems
• First spacecraft to reach interstellar space
• RTGs still operating
• Currently exploring beyond our solar system
• Launched on August 20, 1977
• Only spacecraft to visit Jupiter, Saturn, Uranus and Neptune
• Currently exploring the edge of the solar system

Each powered by:

• 3 Multi-Hundred Watt (MHW) RTGs stacked in a series on a boom, producing about 158 W e each, at launch.

As the electrical power decreases, power loads on the spacecraft must be turned off in order to avoid having demand exceed supply. As loads are turned off, some spacecraft capabilities are eliminated.

Voyager Goals & Accomplishments

Voyager 1 and 2 were designed to take advantage of a rare planetary alignment to explore the outer solar system. Voyager 1 targeted Jupiter and Saturn before continuing on to chart the far edges of our solar system. Voyager 2 targeted Jupiter, Saturn, Uranus and Neptune before joining its sister probe on their interstellar mission.

Voyager proved to be one of the greatest missions of discovery in history. Among their many revelations about the solar system are:

• Rings around Jupiter
• Volcanoes on Jupiter's moon Io
• Moons of Saturn that shepherd its rings
• New moons around Uranus and Neptune
• Geysers of liquid nitrogen on Neptune's moon Triton
• Revealed and crossed the farthest boundary of our solar system

Voyager 2 is the only spacecraft to study all four of the solar system's giant planets at close range. The Voyagers are now exploring the outermost reaches of our sun's influence, where the solar wind mixes with the interstellar wind of our galaxy. Their long-lived power source has enabled these explorers to continue teaching us about our solar system for more than years after they left earth.

• Go to Voyager Homepage
• Go to Voyager Image Gallery
• Status: Where are the Voyagers?

Mission Elapsed Time

Engineers Pinpoint Cause of Voyager 1 Issue, Are Working on Solution

Engineers have confirmed that a small portion of corrupted memory in one of the computers aboard NASA’s Voyager 1 has been causing the spacecraft to send unreadable science and engineering data to Earth since last November. Called the flight data subsystem (FDS), the computer is responsible for packaging the probe’s science and engineering data before the telemetry modulation unit (TMU) and radio transmitter send the data to Earth.

In early March , the team issued a “poke” command to prompt the spacecraft to send back a readout of the FDS memory, which includes the computer’s software code as well as variables (values used in the code that can change based on commands or the spacecraft’s status). Using the readout, the team has confirmed that about 3% of the FDS memory has been corrupted, preventing the computer from carrying out normal operations.

The team suspects that a single chip responsible for storing part of the affected portion of the FDS memory isn’t working. Engineers can’t determine with certainty what caused the issue. Two possibilities are that the chip could have been hit by an energetic particle from space or that it simply may have worn out after 46 years.

Although it may take weeks or months, engineers are optimistic they can find a way for the FDS to operate normally without the unusable memory hardware, which would enable Voyager 1 to begin returning science and engineering data again.

Launched in 1977 , the twin Voyager spacecraft flew by Saturn and Jupiter, and Voyager 2 flew by Uranus and Neptune. They are both exploring interstellar space, outside the bubble of particles and magnetic fields created by the Sun, called the heliosphere. Voyager 2 continues to operate normally.

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

Engineers attempt to fix a computer glitch on Voyager 1

Voyager 1's system that sends data home is malfunctioning, preventing the computer from operating as it should.

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Last November, the Voyager 1 spacecraft began sending gibberish radio signals back to Earth. Engineers have now identified the problem, but trying to repair a 46-year-old device on a craft 24 billion kilometres from Earth is not easy.

Voyager 1 and its twin Voyager 2 were both launched in 1977 on a reconnaissance mission to Jupiter and Saturn. They were designed to fly past the giant planets to obtain closeup images of those distant worlds and their myriad of moons.

Both spacecraft performed beyond expectations, discovering many new moons — some covered in ice , one with active volcanoes , another with a thick atmosphere and closeup details of Saturn's rings .  

Following the Saturn encounter, Voyager 1 was flung upwards by Saturn's gravity on a trajectory northward, above the orbital plane in which most of the planets orbit the Sun, out of our solar system. NASA extended its mission and from there it went on to become the first human-made object to venture into interstellar space in 2012. 

Voyager 2, however, was aimed toward Uranus and Neptune, which were conveniently positioned in a rare alignment with Jupiter and Saturn making it the only spacecraft to visit those distant worlds.

Following the grand tour of the outer solar system, Voyager 2 was also tossed out toward interstellar space in 2018 when its mission was extended and where it continues on its journey today. 

• After a 42-year journey, Voyager 2 goes interstellar
• Voyager 1 picks up the 'hum' of interstellar space

While their primary missions were over, both spacecraft were still in good health, thanks largely to their nuclear power sources or Radioisotope Thermoelectric Generators (RTG). These containers hold small amounts of plutonium which provide heat that is turned directly into electricity with no moving parts. They have an expected lifetime of around 50 years and have kept the Voyagers' instruments running.

Now, as both spacecraft continue their journey through the space between the stars, they are showing signs of their age.

For Voyager 1, the problem seems to be in the flight data subsystem (FDS) that packages data from the scientific instruments for transmission to Earth. The scientists don't know if the faulty module was corrupted by cosmic rays or just worn out, but they say they're optimistic they may be able to work around the problem, although it will take some time.

Engineers have confirmed that corrupted memory aboard my twin <a href="https://twitter.com/hashtag/Voyager1?src=hash&amp;ref_src=twsrc%5Etfw">#Voyager1</a> has been causing it to send unreadable data to Earth. It may take months, but our team is optimistic they can find a way for the FDS to operate normally again: <a href="https://t.co/qe5iQUu4Oj">https://t.co/qe5iQUu4Oj</a> <a href="https://t.co/AGFBZFz53v">https://t.co/AGFBZFz53v</a> &mdash; @NASAVoyager

The challenge is that the computers were built in the 1970s using old code and send data very slowly by today's standards.

In addition, these computers are so deep in space, it takes 22.5 hours for a radio signal from Voyager 1 to reach Earth. That means the controllers on the ground have to wait 45 hours for each two-way communication with the spacecraft.

Given how very, very far they are from home, if something goes wrong with them, it's up to engineers on the ground to fix it by sending radio signals since reaching them for repair missions isn't possible. We're a long way from the fictional warp drive and sub-space communication that made life so easy on the Starship Enterprise of Star Trek fame. 

The twin Voyagers are now the most distant objects ever sent from Earth; a demonstration of how vast space is and how slow our spacecraft are. In 1977, I attended the launch of Voyager 2 when my hair was black and skin was smooth. This one mission with Voyager 1 and 2 has occupied a good chunk of my lifetime.

In another few years, the RTGs on both Voyagers are expected to run down to the point where the spacecraft will no longer be able to communicate with Earth. They will just continue to drift in silence among the stars of the Milky Way for billions of years. 

However, there is one item on both Voyagers that will continue to function, the Golden Record, which carries a message from Earth to anyone out there who may find the spacecraft in the future.

The chances of them being found are astronomically small, but they will become the longest running experiment in human history.

ABOUT THE AUTHOR

Bob McDonald is the host of CBC Radio's award-winning weekly science program, Quirks & Quarks. He is also a science commentator for CBC News Network and CBC TV's The National. He has received 12 honorary degrees and is an Officer of the Order of Canada.

• Quirks & Quarks
• Bob McDonald's recent columns

Quick Facts

Voyager 1 is escaping the solar system at a speed of about 3.5 AU per year

Voyager 2 is escaping the solar system at a speed of about 3.1 AU per year

Five spacecraft - Voyagers 1 and 2; Pioneers 10 and 11; and New Horizons are on an interstellar trajectory.

Voyager's computers procees about 8,000 instructions per section. A modern smartphone yields more than 14 billion instructions per second.

Can the Voyager imaging cameras be turned back on?

It is possible for the cameras to be turned on, but it is not a priority for Voyager's Interstellar Mission. After Voyager 1 took its last image (the "Solar System Family Portrait" in 1990), the cameras were turned off to save power and memory for the instruments expected to detect the new charged particle environment of interstellar space. Mission managers removed the software from both spacecraft that controls the camera. The computers on the ground that understand the software and analyze the images do not exist anymore. The cameras and their heaters have also been exposed for years to the very cold conditions at the deep reaches of our solar system. Even if mission managers recreated the computers on the ground, reloaded the software onto the spacecraft and were able to turn the cameras back on, it is not clear that they would work.

In addition, it is very dark where the Voyagers are now. While you could still see some brighter stars and some of the planets with the cameras, you can actually see these stars and planets better with amateur telescopes on Earth.

What instruments on the spacecraft are still working and what have been turned off?

View an updated list of the status o/f Voyager instruments: Mission Status .

How long can Voyager 1 and 2 continue to function?

Editor's note: Both Voyagers were still functioning in January 2024.

The radioisotope thermoelectric generator (RTG) on each spacecraft puts out 4 watts less each year. Because of this diminishing electrical power, the Voyager team has had to prioritize which instruments to keep on and which to turn off. Heaters and other systems have also been turned off one by one as part of power management.

The Voyager team has chosen to keep operating the instruments that are the most likely to send back key data about the heliosphere and interstellar space -- the fields and particles instruments. Engineers expect to begin turning off fields and particles science instruments one by one, starting in 2020 for Voyager 2. Voyager 2 will have to start turning science instruments off sooner because it is currently operating one more instrument than Voyager 1. Engineers expect each spacecraft to continue operating at least one science instrument until around 2025.

Even if science data won't likely be collected after 2025, engineering data could continue to be returned for several more years. The two Voyager spacecraft could remain in the range of the Deep Space Network through about 2036, depending on how much power the spacecraft still have to transmit a signal back to Earth.

Where are Voyager 1 and 2 today?

Where is Voyager 1 going? When will it get there? How about Voyager 2?

Voyager 1 is escaping the solar system at a speed of about 3.5 AU per year, 35 degrees out of the ecliptic plane to the north, in the general direction of the solar apex (the direction of the sun's motion relative to nearby stars). Voyager 1 will leave the solar system aiming toward the constellation Ophiuchus. In the year 40,272 AD (more than 38,200 years from now), Voyager 1 will come within 1.7 light years of an obscure star in the constellation Ursa Minor (the Little Bear or Little Dipper) called AC+79 3888.

Voyager 2 is escaping the solar system at a speed of about 3.1 AU per year, 48 degrees out of the ecliptic plane to the south toward the constellations of Sagittarius and Pavo. In about 40,000 years, Voyager 2 will come within about 1.7 light years of a star called Ross 248, a small star in the constellation of Andromeda..

Where do we consider our solar system to end; Pluto's orbit? Solar apex?

The solar system may be broadly defined as consisting of all those objects that are ultimately governed by the gravitational field of the sun. In addition to the planets, moons, asteroids and dust of the planetary system, it includes the distant bodies of the Kuiper Belt and Oort cloud, the last extending perhaps as far as 50,000 astronomical units (1 AU = about 93 million miles). The gravitational influence of the sun may extend as far as 2 light years. (From "Solar System", James H. Shirley, in Encyclopedia of Planetary Science).

That said, Pluto (and sometimes Neptune) is the most distant planet in our planetary system. The Voyagers passed the orbit of Neptune (which was furthest at the time) in August 1989. Neither flew by Pluto, which was elsewhere in its orbit at the time.

Another concept is the heliosphere, which is a bubble around the sun created by the outward flow of the solar wind from the sun and the opposing inward flow of the interstellar wind. That heliosphere is the region influenced by the dynamic properties of the sun that are carried in the solar wind - such as magnetic fields, energetic particles, solar wind plasma, etc. Voyager 1, which is traveling up away from the plane of the planets, passed out of the heliosphere into interstellar space, beyond the bubble of the solar wind, on Aug. 25, 2012. Voyager 2, which is traveling below the plane of the planets, is expected to enter interstellar space in the coming years.

Have any human-made objects ever exited the solar system?

Sometimes, it is written that Voyager and Pioneers 10 and 11 have exited the solar system. Though all of these spacecraft have gone beyond all the planets of the solar system, they have not exited the solar system, based on the scientific definition. To leave the solar system, they need to pass beyond the Oort Cloud. Voyager 1 was the first-ever object to reach interstellar space on August 25, 2012 when it passed beyond the sun’s realm of plasma influence (the heliosphere) and it is the most distant human-made object. But it will take about 300 years for Voyager 1 to reach the inner edge of the Oort Cloud and possibly about 30,000 years to fly beyond it. Voyager 2 has not yet reached interstellar space or exited the heliosphere (bubble of solar plasma). Pioneer 10 and 11 are no longer transmitting science data back to Earth.

Are the distance counters rolling backwards?

Often they are, and it's actually not an error. This is caused by the fact that Earth moves around the sun more quickly than either Voyager spacecraft is departing from Earth. So, at certain times of the year, the distance between Earth and each Voyager actually decreases.

Did either of the Voyagers visit Pluto? Why didn't the Voyagers fly by Pluto?

Both Voyagers flew beyond the orbit of Pluto/Neptune in 1989, but neither flew by Pluto, which was elsewhere in its orbit at the time. It was never planned that the Voyagers would visit Pluto.

The original mission of Voyager was to explore Jupiter and Saturn. Two spacecraft were sent on slightly different paths, first to Jupiter and then, with gravity assists, on to Saturn. Voyager 1 could have been aimed on to Pluto, but exploration of Titan and the rings of Saturn was a primary scientific objective. This caused the trajectory to be diverted upward out of the ecliptic plane such that no further planetary encounters were possible for Voyager 1. Once Voyager 1 had successfully gathered data at Titan, Voyager 2 was allowed to go on to Uranus and Neptune. Voyager 2, theoretically, could have been aimed for Pluto, but the aim point would have been inside the planet of Neptune - not very practical. NASA's New Horizons spacecraft visited Pluto in July 2015.

When we send spacecraft through the asteroid belt to the outer planets, how do we navigate the craft through the belt?

Pioneers 10 and 11 had preceded the Voyagers to Jupiter and the asteroid belt was a major concern for them. By the 1960's more than 3000 minor planets had been discovered and their orbits well determined. Even 50,000 minor bodies spread over the volume of space occupied by the asteroid belt would produce little direct danger, although a chance collision with an uncatalogued object was possible.

"While the largest of the asteroids were known and their orbits charted, many of the asteroids moved in unknown orbits. Although the risk of a spacecraft colliding with a charted asteroid was negligible, there was no way to estimate how many particles the size of a grain of sand might be present in the asteroid belt to collide with the spacecraft and seriously damage it". (From Pioneer, First to Jupiter, Saturn and Beyond, NASA SP-446, 1980) Only by going there could the danger be properly assessed - and Pioneer was first.

I was reading Dr. Carl Sagan's biography recently and found that he persuaded NASA administrators to turn one of the Voyager space probes around in order to take a last image of the solar system. Is this true? Do the craft send back any images of where they are?

I think you are referring to the series of photos taken by Voyager 1 on Valentine's Day 1990. These were the final images taken by either of the Voyager spacecraft.

On Feb. 14, 1990, after the spacecraft had passed the orbits of Neptune and Pluto, the cameras of Voyager 1 pointed back toward the sun and took a series of pictures of the sun and the planets, making the first ever 'portrait' of our solar system as seen from the outside.

I can not locate a copy of the Murmurs of Earth CD. Would you know of a vendor that might sell copies of it?

There was a book and CDROM published by Warner New Media in 1992. The book was a reprint of the Carl Sagan, et al, "Murmurs of Earth" that was originally published in 1978.

Carl Sagan and his colleagues did the assemblage of the information on the Voyager Golden Phonograph Record. Most of the material they used was copyrighted by the creators/owners and Sagan had to get copyright releases in order to assemble the original record. Subsequently, Warner Multimedia was able to obtain copyright releases for the 1992 version of "Murmurs of Earth", by Carl Sagan, et al and included all the sounds and songs on the CDROM set that accompanied the Warner New Media release of the book. We have included on the Voyager web site only that information for which we were able to get release, that's why everything, especially the music and the photos, is not there.

Unfortunately, the book and CDROM are no longer being published and are hard to find as a set. Your best bet to find one quickly may be in a public or university library or at a used bookstore. You might try used bookstores on line at http://www.bookfinder.com/ and search on: Author: Carl Sagan Title: Murmurs of Earth

You can find many instances where the book is for sale at prices around $40 US or less (most less than $20), but few (if any) include the CDROM. Look for availability of 1992 or later versions.

If there is intelligent life in our universe and they were not a peace loving species, wouldn't the information on the Voyager be enough to destroy human kind?

We have received almost nothing but praise for the inclusion of the Golden Phonograph Record on Voyager. We have also received lots of compliments on the contents, however, that praise rightly belongs to Carl Sagan and his colleagues who chose, assembled and got permission to use the material.

There were a few detractors, even as Sagan was formulating the disk.

In the Sagan, et al book, "Murmurs of Earth, the Voyager Interstellar Record", while describing some of his earlier work in sending messages from the Arecibo radar, spoke of two protests to that effort. Excerpts from that passage follow:

"One was from a few scientists who worried that we hadn't corrected for the speed of Earth in space in launching the message. ...............The other protest was a serious one, made by Sir Martin Ryle, a Nobel laureate and the Astronomer Royal of England. He wrote with great anxiety that he felt it was very hazardous to reveal our existence and location to the galaxy. For all we know, any creatures out there were malevolent or hungry, and once they knew of us, the might come to attack or eat us...........Many other less knowledgeable people had the same concerns.

"The fact is, for better or for worse, we have already announced our presence and location to the universe, and continue to do so every day. There is a sphere of radio transmission about thirty light years thick expanding outward at the speed of light, announcing to every star it envelops that the earth is full of people. Our television programs flood space with signals detectable at enormous distances by instruments not much greater than our own. It is a sobering thought that the first news of us may be the outcome of the Super Bowl.

"........... Whether or not Sir Martin Ryle is justified in his anxieties about revealing the location of our civilization is of course a debatable subject. Even so, it is too late to worry about it, so we might as well try to be friendly".

What were the most important discoveries of the Voyager space probes?

There are so many. Voyager is probably the most scientifically productive mission ever. It was only the second mission to visit Jupiter and Saturn and the only one to visit Uranus and Neptune. Voyager 1 and 2 obtained the first detailed profiles of the atmospheres of Saturn, Uranus and Neptune and improved our understanding of the characteristics of the atmosphere of Jupiter. The Voyager spacecraft revealed the enormous amount of detail in the rings of Saturn, discovered the rings of Jupiter and provided the first detailed images of the rings of Uranus and Neptune. Voyager imaged Earth's moon and discovered twenty-three new moons at the outer planets. Voyager made significant improvements in the measurements of the magnetospheres at Jupiter and Saturn and provided the first measurements of the magnetospheres at Uranus and Neptune. The significance of the Voyager is the vast amount of new knowledge about our outer solar system it provided and the interest in further exploration it generated. That interest has resulted in the Galileo mission to Jupiter and the Cassini mission to Saturn as well as the discovery of three new satellites at Saturn using Earth-based instruments.

Discovery of active volcanism on Io, a satellite of Jupiter, was probably the greatest surprise. It was the first time active volcanoes had been seen on another body in the solar system. It appears that activity on Io affects the entire Jovian system.

How big is Voyager? How much does it weigh?

The Voyager spacecraft weight, including hydrazine, at launch was 815 kg or about 1797 pounds. It was almost the weight and size of a sub-compact car. The current approximate weight of Voyager 1 is 733 kg and Voyager 2 is 735 kg. The difference is in the amount of hydrazine remaining. Hydrazine is being used to control the spacecrafts' attitude.

The spacecraft, without the various booms could fit inside a cube that is about 4 meters on each side. The approximate measurements of the different structures follow:

• The high gain antenna is 3.7 meters across (diameter).
• The magnetometer boom is 13 meters long
• The two Planetary Radio Astronomy and Plasma Wave antenna are 10 meters long.
• The Radioisotope Thermoelectric Generator boom is 3.7 meters long
• The science instrument boom (near top of picture) is 3 meters long.
• The Bus Housing Electronics is about 1.8 meters in diameter.

The spacecraft height - from the top of the reflector structure in the middle of the high gain antenna to the bottom of the triangular feet below the bus housing electronics - is about 3.8 meters

The launch vehicle was a Titan III E/ Centaur rocket, which stands nearly 50 m (164 ft) high and weighs almost 635,000 kg (1.4 million lb).

Is it true that a sketch by Da Vinci is included in the "Message to the Universe" of Voyagers 1 and 2?

There are messages on the Voyagers in the form of a phonograph record and drawings on the cover that protects the record. However, Leonardo Da Vinci's Vitruvian Man was not part of the Voyager Golden Phonograph Record, the Voyager cover, or the Pioneer plaque. Read more about the golden record .

What kind of computers are used on the Voyager spacecraft?

There are three different computer types on the Voyager spacecraft and there are two of each kind. Total number of words among the six computers is about 32K.

• Computer Command System (CCS) - 18-bit word, interrupt type processors (2) with 4096 words each of plated wire, non-volatile memory.
• Flight Data System (FDS) - 16-bit word machine (2) with modular memories and 8198 words each
• Attitude and Articulation Control System (AACS) - 18-bit word machines (2) with 4096 words each.

According to my calculations, that's a total of about 68KB, or small potatoes compared to today's microprocessors. We probably could perform all functions with one of today's boards and still have room for solid state data storage and much more fault detection software. We would still need a second unit for redundancy. Today's microprocessors are also much faster than the chips used on Voyager and a comparative system would use less electrical power. On the other hand, software might be more complicated as opposed to that used in an interrupt type system, but it would be much more capable and more flexible.

Let's look closer at the CCS. The CCS has two main functions: to carry out instructions from the ground to operate the spacecraft, and to be alert for a problem or malfunction and respond to it. Two identical 4096- word memories contain both fixed routines (about 2800 words) and a variable section (about 1290 words) for changing science sequences. The CCS issues commands to the AACS for movement of the scan platform or spacecraft maneuvers; to the FDS for changes in instrument configurations or telemetry rates and to numerous other subsystems within the spacecraft for specific actions. Fault-protection algorithms are also stored in the CCS, occupying roughly 10 percent of the CCS memory.

The main functions of the FDS are to collect data from, and controls the operations of, the scientific instruments; and to format engineering and science data for on-board storage and/or real-time transmission. The FDS also keeps the spacecraft "time" and provides frequency references to the instruments and other spacecraft subsystems.

The Voyager spacecraft computers are interrupt driven computer, similar to processors used in general purpose computers with a few special instructions for increased efficiency. The programming is a form of assembly language.

There is no clock chip, as such, in the spacecraft. The "clock" is really a counter, based on one of several electronically generated frequencies. These frequencies, based on a reference, generated by a very stable oscillator, are converted and fed to different locations in the spacecraft as synchronization signals, timers, counters, etc. The "clock" signal is part of the information telemetered to the ground and it is with ground software that we convert to day of year, time of day Greenwich Mean Time.

Voyager was built in-house at JPL; the computers were manufactured by General Electric to JPL specifications.

How fast are the Voyager computers?

Not very fast compared to today’s standards. The master clock runs at 4 MHz but the CPU’s clock runs at only 250 KHz. A typical instruction takes 80 microseconds, that is about 8,000 instructions per second. To put this in perspective, a 2013 top-of-the-line smartphone runs at 1.5 GHz with four or more processors yielding over 14 billion instructions per second.

What is the "direction" (constellation and/or star) both Voyager 1 & 2 and the Pioneers are "aimed" for, at present.

• Pioneer 10 is headed towards the constellation of Taurus (The Bull). It will take Pioneer over 2 million years to pass by one of the stars in the constellation.
• Pioneer 11 is headed toward the constellation of Aquila (The Eagle), Northwest of the constellation of Sagittarius. Pioneer 11 may pass near one of the stars in the constellation in about 4 million years.
• Voyager 1 is escaping the solar system at a speed of about 3.5 AU per year, 35 degrees out of the ecliptic plane to the north, in the general direction of the Solar Apex (the direction of the Sun's motion relative to nearby stars). Voyager 1 will leave the solar system aiming toward the constellation Ophiuchus. In the year 40,272 AD, Voyager 1 will come within 1.7 light years of an obscure star in the constellation Ursa Minor (the Little Bear or Little Dipper) called AC+79 3888.
• Voyager 2 is also escaping the solar system at a speed of about 3.1 AU per year, 48 degrees out of the ecliptic plane to the south toward the constellations of Sagitarrius and Pavo. In about 40,000 years, Voyager 2 will come within about 1.7 light years of a star called Ross 248, a small star in the constellation of Andromeda.

Where can I find pictures of what the Voyager spacecraft took?

You can view pictures from Voyager and other missions at several locations:

• NSSDC Planetary Image Catalog http://nssdc.gsfc.nasa.gov/imgcat
• Planetary Photojournal http://photojournal.jpl.nasa.gov/
• NSSDC Photo Gallery http://nssdc.gsfc.nasa.gov/photo_gallery

Is there some sort of plate with pictograms on the Voyager 1 spacecraft? Also is it similar to the Pioneer spacecraft plaque?

You asked about the Voyager plate. I'm assuming you mean the engravings on the aluminum record cover on each of the two Voyagers. You can see the record cover installed on the spacecraft bus . Also, from Carl Sagan's book, "Murmurs of Earth", here is a description of the cover engravings:

"In the upper left-hand corner is an easily recognized drawing of the phonograph record and the stylus carried with it. The stylus is in the correct position to play the record from the beginning. Written around it in binary arithmetic is the correct time of one rotation of the record, 3.6 seconds, expressed in time units of 0,70 billionths of a second, the time period associated with a fundamental transition of the hydrogen atom. The drawing indicates that the record should be played from the outside in. Below this drawing is a side view of the record and stylus, with a binary number giving the time to play one side of the record - about an hour.

"The information in the upper right-hand portion of the cover is designed to show how pictures are to be constructed from the recorded signals. The top drawing shows the typical signal that occurs at the start of a picture. The picture is made from this signal, which traces the picture as a series of vertical lines, similar to ordinary television (in which the picture is a series of horizontal lines). Picture lines 1, 2 and 3 are noted in binary numbers, and the duration of one of the "picture lines," about 8 milliseconds, is noted. The drawing immediately below shows how these lines are to be drawn vertically, with staggered "interlace" to give the correct picture rendition. Immediately below this is a drawing of an entire picture raster, showing that there are 512 vertical lines in a complete picture. Immediately below this is a replica of the first picture on the record to permit the recipients to verify that they are decoding the signals correctly. A circle was used in this picture to insure that the recipients use the correct ratio of horizontal to vertical height in picture reconstruction.

"The drawing in the lower left-hand corner of the cover is the pulsar map previously sent as part of the plaques on Pioneers 10 and 11. It shows the location of the solar system with respect to 14 pulsars, whose precise periods are given. The drawing containing two circles in the lower right-hand corner is a drawing of the hydrogen atom in its two lowest states, with a connecting line and digit 1 to indicate that the time interval associated with the transition from one state to the other is to be used as the fundamental time scale, both for the time given on the cover and in the decoded pictures.

"Electroplated onto the record's cover is an ultra-pure source of uranium-238 with a radioactivity of about 0.00026 microcuries. The steady decay of the uranium source into its daughter isotopes makes it a kind of radioactive clock. Half of the uranium-238 will decay in 4.51 billion years. Thus, by examining this two-centimeter diameter area on the record plate and measuring the amount of daughter elements to the remaining uranium-238, an extraterrestrial recipient of the Voyager spacecraft could calculate the time elapsed since a spot of uranium was placed aboard the spacecraft. This should be a check on the epoch of launch, which is also described by the pulsar map on the record cover."

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NASA confirms nuclear-powered Dragonfly drone is going to Titan

Whew relief for boffins as rotorcraft slated to arrive at saturn moon in 2034.

NASA has finally confirmed its Dragonfly rotorcraft mission will be heading to Titan, one of Saturn's Moons, meaning the team behind the project can finalize its design and get to work building the spacecraft.

Things had been looking a little risky for the drone as budgets were squeezed and launch dates shifted – Dragonfly was originally slated for launch in 2026. But yesterday NASA approved the mission and the July 2028 launch date, with a scheduled arrival at Titan in 2034.

The total lifecycle cost of the mission is currently $3.35 billion, approximately double the proposed cost. The increases were blamed on the COVID-19 pandemic, supply chain issues, and "the results of an in-depth design iteration." The project was also directed to replan multiple times due to funding constraints in fiscal years 2020 and 2022.

Artist illustration of NASA's Dragonfly over the dunes of Saturn’s Titan ... Credit: NASA/Johns Hopkins APL/Steve Gribben - Click for source

Additional funding has been provided for a heavy-lift launch vehicle to cut the time needed for the cruise phase to Saturn. NASA did not specify which heavy-lift launcher would be used, although the agency did use the SpaceX Falcon Heavy to launch the Psyche mission in 2023 and plans to use the rocket for its Europa Clipper later in 2024.

Confirmation of the Titan visit is a spark of optimism amid budgetary gloom at NASA. The increasing costs of the Mars Sample Return expedition combined with funding constraints could mean cannibalization for some of the agency's other projects. It is, therefore, a relief for many engineers and scientists that DragonFly, which is to be designed and built under the direction of the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, received its confirmation.

Powered by a Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) – like the Mars Curiosity rover – the Dragonfly dual-quadcopter drone is expected to travel hundreds of kilometers during its planned two-year exploration of Titan.

According to the team, "In under an hour, Dragonfly will cover tens of miles or kilometers, farther than any planetary rover has traveled."

The vehicle will, however, spend most of its time on the surface of Titan, making science measurements.

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Titan has long fascinated scientists. The Voyager probes imaged the moon in 1979 and 1980, but the organic haze in the atmosphere obscured the surface in visible wavelengths. In 2004, the Cassini orbiter arrived and mapped much of the moon's surface. In 2005, Cassini released the Huygens probe, which parachuted to the surface.

If everything goes according to plan, almost 30 years later, it will be the turn of Dragonfly to inspect the surface of Titan. ®

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