size of voyager 1

Voyager 1 Now Most Distant Human-Made Object in Space 

In a dark, cold, vacant neighborhood near the very edge of our solar system, the Voyager 1 spacecraft is set to break another record and become the explorer that has traveled farthest from home.

At approximately 2:10 p.m. Pacific time on February 17, 1998, Voyager 1, launched more than two decades ago, will cruise beyond the Pioneer 10 spacecraft and become the most distant human-created object in space at 10.4 billion kilometers (6.5 billion miles.) The two are headed in almost opposite directions away from the Sun. As with other spacecraft traveling past the orbit of Mars, both Voyager and Pioneer derive their electrical power from onboard nuclear batteries.

"For 25 years, the Pioneer 10 spacecraft led the way, pressing the frontiers of exploration, and now the baton is being passed from Pioneer 10 to Voyager 1 to continue exploring where no one has gone before," said Dr. Edward C. Stone, Voyager project scientist and director of NASA's Jet Propulsion Laboratory.

"At almost 70 times farther from the Sun than the Earth, Voyager 1 is at the very edge of the Solar System. The Sun there is only 1/5,000th as bright as here on Earth -- so it is extremely cold and there is very little solar energy to keep the spacecraft warm or to provide electrical power. The reason we can continue to operate at such great distances from the Sun is because we have radioisotope thermal electric generators (RTGs) on the spacecraft that create electricity and keep the spacecraft operating," Stone said. "The fact that the spacecraft is still returning data is a remarkable technical achievement."

Voyager 1 was launched from Cape Canaveral on September 5, 1977. The spacecraft encountered Jupiter on March 5, 1979, and Saturn on November 12, 1980.

Then, because its trajectory was designed to fly close to Saturn's large moon Titan, Voyager 1's path was bent northward by Saturn's gravity, sending the spacecraft out of the ecliptic plane - the plane in which all the planets except Pluto orbit the Sun.

Launched on March 2, 1972, the Pioneer 10 mission officially ended on March 31, 1997. However NASA's Ames Research Center, Moffet Field, CA, intermittently receives science data from Pioneer as part of a training program for flight controllers of the Lunar Prospector spacecraft now orbiting the Moon.

"The Voyager mission today presents an unequaled technical challenge. The spacecraft are now so far from home that it takes nine hours and 36 minutes for a radio signal traveling at the speed of light to reach Earth,"said Ed B. Massey, project manager for the Voyager Interstellar Mission. "That signal, produced by a 20 watt radio transmitter, is so faint that the amount of power reaching our antennas is 20 billion times smaller than the power of a digital watch battery,"

Having completed their planetary explorations, Voyager 1 and its twin, Voyager 2, are studying the environment of space in the outer solar system. Although beyond the orbits of all the planets, the spacecraft still are well within the boundary of the Sun's magnetic field, called the heliosphere. Science instruments on both spacecraft sense signals that scientists believe are coming from the outermost edge of the heliosphere, known as the heliopause.

The heliosphere results from the Sun emitting a steady flow of electrically charged particles called the solar wind. As the solar wind expands supersonically into space in all directions, it creates a magnetized bubble -- the heliosphere -- around the Sun. Eventually, the solar wind encounters the electrically charged particles and magnetic field in the interstellar gas. In this zone the solar wind abruptly slows down from supersonic to subsonic speed, creating a termination shock. Before the spacecraft travel beyond the heliopause into interstellar space, they will pass through this termination shock.

"The data coming back from Voyager now suggest that we may pass through the termination shock in the next three to five years," Stone said. "If that's the case, then one would expect that within 10 years or so we would actually be very close to penetrating the heliopause itself and entering into interstellar space for the first time."

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

Science data are returned to Earth in real-time to the 34- meter Deep Space Network (DSN) antennas located in California, Australia and Spain. Both spacecraft have enough electricity and attitude control propellant to continue operating until about 2020, when electrical power produced by the RTGs will no longer support science instrument operation. At that time, Voyager 1 will be almost 150 times farther from the Sun than the Earth -- more than 20 billion kilometers (almost 14 billion miles) away.

On Feb. 17, Voyager 1 will be 10.4 billion kilometers (6.5 billion miles) from Earth and is departing the Solar System at a speed of 17.4 kilometers per second (39,000 miles per hour). At the same time, Voyager 2 will be 8.1 billion kilometers (5.1 billion miles) from Earth and is departing the solar system at a speed of 15.9 kilometers per second (35,000 miles per hour).

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

Interstellar Messengers

Voyager 1 and its twin Voyager 2 are the only spacecraft ever to operate outside the heliosphere, the protective bubble of particles and magnetic fields generated by the Sun. Voyager 1 reached the interstellar boundary in 2012, while Voyager 2 (traveling slower and in a different direction than its twin) reached it in 2018.

Mission Type

Science Targets

Latest News

NASA’s Voyager Team Focuses on Software Patch, Thrusters

NASA’s Voyager Will Do More Science With New Power Strategy

Edward Stone Retires After 50 Years as NASA Voyager’s Project Scientist

Engineers Solve Data Glitch on NASA’s Voyager 1

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

The Interstellar Mission

After completing the first in-depth reconnaissance of the outer planets, the twin Voyagers are on a new mission to chart the edge of interstellar space.

The Golden Record

The contents of the golden record were selected for NASA by a committee led by Carl Sagan of Cornell University.

The Spacecraft

The twin Voyagers are escaping our solar system in different directions at more than 3 astronomical units (AU) a year.

The Pale Blue Dot

The behind-the-scenes story of the making of Voyager 1's iconic image of Earth as "a mote of dust suspended in a sunbeam."

Discover More Topics From NASA

Our Solar System

Heliosphere

• Mobile Site
• Staff Directory
• Advertise with Ars

Filter by topic

• Biz & IT
• Gaming & Culture

Front page layout

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.

reader comments

Channel ars technica.

• International edition
• Australia edition
• Europe edition

40 years and counting: the team behind Voyager’s space odyssey

In 1977, Voyager 1 and 2 started their one-way journey across our galaxy, travelling a million miles a day. Jonathan Margolis meets the dedicated team keeping the craft moving

O n a chilly March morning, Steve Howard, aged 65, is at work in his office on the northern edge of Pasadena, California. Two computer screens are squeezed on to his corner desk along with family photos, a tissue box and tins of Altoids Curiously Strong Peppermints. The office is in a quiet business park by a workaday main road. Next to it is a McDonald’s, where people linger for hours over a $1 coffee, seemingly to keep warm. Over the road there’s a scruffier burger joint, Jim’s, with an M missing from its sign – and, visible from Howard’s window, a landscaping supplies yard.

If the few people walking by on West Woodbury Road, Altadena, or popping into the landscaping place for some patio paving slabs were to peer into Howard’s office, they might guess, seeing the graph-covered twin screens and a third PC at the other end of the desk, that he was, perhaps, a financial adviser or a day trader. But what Steve Howard is actually doing makes this very ordinary all-American scene quite extraordinary.

Howard is a Nasa mission controller. He is sending instructions to a probe in interstellar space, 12 billion miles from Earth, beyond Pluto and escaping our Solar System at 1 million miles a day. The 815kg craft, Voyager 1 , is one of two identical machines that for many years now have been the furthest human-made objects from Earth. Howard’s computer code takes 17 hours at the speed of light to reach Voyager 1, the furthest travelled. Voyager 2, which is leaving the solar system in a different direction, is 3bn miles closer. The responses, from transmitters on the twin probes running 23 watts of power – have the power of a billionth of a billionth of a watt by the time they reach Earth.

“So here, see, I have Voyager 1’s status and information up, at least as it was 17 hours ago,” Howard explains. “Right now I’m connected to our Canberra station, and these are seven commands, set to radiate one every five minutes starting 30 minutes from now. They’re to verify that the spacecraft can receive and reset its timer. Such is the speed of light, I will not get confirmation that all is OK until late tomorrow night, but it will have entailed a 25bn-mile round trip, so that’s not too bad.”

It is no hyperbole to say, then, that the man tapping away at his keyboard on the office park next to McDonald’s is a key figure in the greatest-ever feat of human exploration. There was nothing like the Voyager 1 and 2 missions to the outer planets before they launched in 1977, and although three outer planet probes launched last decade are still on mission, no new ventures into deep space are planned.

Space exploration tends to be more inward looking today than in the so-called Space Age. The famous Curiosity rover is of course still working wonders on Mars, but almost all the US’s coming spacecraft will be restricted to studying our own planet, with special attention to environmental issues. The Voyagers and the people like Howard who still work on them full-time – having, in many cases, done so their entire adult life – are from a different era, when budgets were unrestrained, audaciousness (and showing off to the Soviets) was in vogue and the environment was a concern only for hippies.

Voyager’s spindly limbed, Transit-van-sized machines have been travelling at around 37,000mph for almost 38 years. When they were launched, wooden-framed Morris 1000 Traveller cars had only recently stopped being produced by British Leyland in Oxford. The Voyagers’ on-board computers are early 1970s models that were advanced then but are puny now – an iPhone’s computer is some 200,000 times faster and has about 250,000 times more memory than Voyager’s hardware.

The Voyager mission’s early 70s-inspired and -equipped trip, originally meant to last four years, took the craft initially to Jupiter, then Saturn, then, as a bonus since everything was working well, to Uranus and finally Neptune, after which they spun off into their journey around the Milky Way. Against all expectations their vintage electronics and thrusters are still, mostly, working in the intense -253C cold of outer space. What’s more, their sensors are sending data all day every day, as some will continue to do until 2036. That said, by 2025 almost all the instruments sending worthwhile scientific information will be turned off as the ships’ tiny plutonium-238 power sources dwindle.

The on-board camera on each Voyager, for instance, was deactivated to save power 25 years ago last Valentine’s Day. This was after Voyager 1 took a now-iconic “family portrait” of the solar system from almost 4bn miles out. It captured Neptune, Uranus, Saturn, Jupiter, Venus, Earth (seen, in the late astrophysicist Carl Sagan ’s phrase, as a “pale blue dot”) and the Sun, by then just a tiny point of light. By 2036 the craft will be nearly out of the solar system altogether and will remain dead, although in perfect condition, probably for eternity.

It is the Voyager spacecrafts’ longevity, despite their becoming a bit arthritic in later years, that has led to their Mission Control being moved out to an office park. The problem for Nasa – more correctly for the California Institute of Technology’s Jet Propulsion Laboratory , which runs most robotic missions for Nasa – is that high-profile later expeditions, most notably Curiosity, have used the available space on CalTech’s campus. Proud as JPL is of the amazing Voyager story, the craft are not taking photos or doing a lot of sexy science any more and may not encounter anything of much interest for another 40,000 years, by which time they will be deaf and mute. So, like a great grandfather who stubbornly refuses to do the decent thing, the Earth end of the Voyager programme and the spacecraft’s devoted carers have been put in a somewhat off-piste rest home.

Engineers are not given to emotion, but the romance of this incredible voyage of discovery has, by their own account, kept the ageing mission team together. Even latecomers, who were at school when Voyager was launched, have been working on the same mission for 30 years and more. “I’m in my mid-50s and treat the craft like my ageing parents,” says Suzy Dodd , who was 16 at launch, joined as a graduate student and whose card now proclaims surely one of the cooler job titles in science: Project manager, Voyager Interstellar Mission.

“You treat them with a certain amount of reverence; you know they’re stately spacecraft, venerable senior citizens, and you want to do everything possible for them to have a healthy lifetime,” she says. “You need to help them a bit because things have failed and you want to be careful other things don’t. Most of the engineers here have dedicated their career to this project. They have turned down opportunities for promotions and other things because they like Voyager so much they want to stay with it.”

It is clear talking to Voyager staff that they genuinely love their spacecraft, even though most were too young to see them before they flew, and it is more than possible that the older ones will have died before the Voyagers bleep their last. But as engineers, they have mixed feelings about the most famous aspect of that romance, the “golden record” that each craft carries. This is a gold-covered copper LP, packed with a needle and cartridge (plus instructions), and containing, in groove form, 115 photos from Earth, a selection of natural sounds from surf to whales, music from a variety of cultures and eras (the modern west is represented by Chuck Berry’s “Johnny B Goode”) and spoken greetings in 55 languages, from Akkadian, spoken in Sumer about 6,000 years ago, to Welsh.

Carl Sagan, who had the initial idea for the record, wrote in the 1970s: “The spacecraft will be encountered and the record played only if there are advanced spacefaring civilisations in interstellar space. But the launching of this bottle into the cosmic ocean says something very hopeful about life on this planet.” Sagan’s son Nick, then an infant, now a science-fiction novelist and screenwriter (his credits include Star Trek episodes), recorded the English message: “Hello from the children of planet Earth.” But one sure to make many tear up is the Mandarin: “Hope everyone’s well. We are thinking about you all. Please come here to visit when you have time.” (The messages are on the Voyager website, voyager.jpl.nasa.gov ).

Voyager’s mission controllers are less starry-eyed than Sagan about the golden records. You sense some feel that it was too much of a bow to religious sentiment. Steve Howard is one of the more positive on the record question. “Even though Earth may not be here, some intelligent being could pick it up and detect it. I would say that many of the civilisations are much more advanced and would detect something like that and simply go in and decipher it,” he says.

Suzy Dodd’s view is more typical of the team’s. “I think it’s a great idea to get humans and mankind thinking what-ifs. Let’s send a picture of ourselves vintage 1977 and put it on a spacecraft and send it out there forever. I think it’s done to connect us to the spacecraft more than for an alien running into it. I’m of the opinion that space is very empty and the chances of something finding it are remote. But that doesn’t diminish the fact that we’ve got a little time capsule out there travelling through space and now orbiting around in our galaxy. And that’s us.”

For the mission’s much-honoured chief scientist and spokesman since 1972, CalTech professor Ed Stone, aged 79, the romance of Voyager lies more in what it has discovered since he joined the project aged 36. “Yes, the Space Age was a young man’s game back then,” he says, not a little ruefully, sitting on a park bench on the green university campus. “We all knew we were on a mission of discovery. We just had no idea how much discovery there would be. We just kept finding things we didn’t know were there to be found.

“For example, before Voyager, the only known volcanoes in the solar system were here on Earth. Then we flew by Jupiter’s moon, Io, which had 10 times the volcanic activity of Earth. Ten times! We detected hot lakes of lava on the surface. That was the first major discovery and it set the tone for the rest of the mission. And there are five instruments still working. But by 2025 the last will go off.”

He doesn’t quite add that by then he will be nearly 90, but does say, smiling: “Thing is, if you want to do space experiments, you have to be optimistic that it’s all going to work and that you’re going to find something worth the work. And you have to be patient, because nothing happens fast in space.”

Stone explains how, although it’s widely considered freakish that the Voyager crafts are still working so well – a TV left permanently on since Jim Callaghan’s day would be hardly working today – it’s less surprising to people like him who built them. To anyone familiar with the inside of a vintage radio or TV, the hand-soldered circuit boards, capacitors, transistors, resistors and so on that run a Voyager would look reassuringly familiar, which isn’t the case with a modern computer or phone, whose microchip-studded innards look more like something out of a UFO.

But the parts in Voyager weren’t as ordinary as they looked. Suzy Dodd, a “newcomer” to the project with just over 30 years’ service, has also been intrigued by the spacecraft’s durability. “The robustness is unique,” she says. “If you talk to the older engineers, they’ll say: ‘Well, we were told to make a four-year mission, but we realised if you just used this higher-rated component, it would last twice as long.’ So they did that. They just didn’t tell anybody. The early engineers were very conscious of trying to make this last as long as possible and, quite frankly, being not as forthcoming with information about the types of parts they were using.”

Even so, Ed Stone says, there have been problems. A ground controller’s error in April 1978 meant that Voyager 2 switched itself irretrievably to its back-up receiver – meaning that the craft has been receiving transmissions from Earth on a dodgy back-up radio for almost the entire mission. One of the original thrusters also failed.

For spacecraft 12bn miles from home and in their dotage, the Voyagers are quite tranquil machines today, but they do need watching. As Steve Howard is in his office inputting code in primordial programming language, on the floor of what passes for the main mission control Enrique Medina, 65, is watching streams of engineering data from the craft. A computer engineer, Medina is another of the eight full- and part-time controllers.

“One of us is always on call,” he says. “We’re all connected all the time by our smartphones. We will hear, that way, which engineering channel is out of tolerance and then we will connect from home with secure IDs and special codes, troubleshoot, determine and sometimes fix it from home. Or in some cases, one of us will drive in. That usually happens four to five times a month.

“Sometimes people are away, but we love Voyager so much that though it’s not part of our employment we’ll come in and do it anyway. Attitude control is my sub-system, but if the propulsion or the power needs attention, we all do multiple jobs,” he adds. “I’ve been working on Voyager since the Uranus encounter in 1986, and I will retire when Voyager retires in 2025. My wife doesn’t like that idea at all, as we already have a retirement place by the beach back in Mexico.”

Medina’s devotion to the Voyager is clear to see. “This has been part of my life for so long, and they pay us to do it, so how can you stop doing something you love? I even talk about the spacecraft like it’s a person, especially if it’s my sub-system.”

Steve Howard feels the same. “I just love to think of everything, all those 65,000 parts on each craft, working up there,” he says. “Oh man, it really is something. Every time we come in here, it’s just a gift. And you know that one day it could stop.”

Do these engineers ever think it might be more fun to be at the controls of Curiosity on the CalTech campus a couple of miles away?

“Yes, maybe,” says Medina, “but after so many years, you’re invested. It’s like being married to someone. It would be interesting to go out with Angelina Jolie, but do I want to give up my wife of 44 years, and my grandkids? I don’t think so. I would not give this up for something more interesting or newer.”

For the most part, Voyager is the reality of space – slow, patient science, humdrum perhaps, but real. It’s only a 20-minute drive from Altadena to Hollywood, where brilliant fake versions of space exploration like Christopher Nolan’s recent Interstellar are confected.

But Voyager, starring real people who keep tissues and tins of Altoids on their desks and real buildings rather than set designers’ glamorous fantasies, just happens to be the only real interstellar mission there will probably be in the lifetime of anyone alive today. It is surely one of the most amazing things in human history.

Follow the Observer Magazine on Twitter @ObsMagazine

• The Observer

Comments (…)

Most viewed.

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

NASA's interstellar Voyager 1 spacecraft isn't doing so well — here's what we know

Since late 2023, engineers have been trying to get the Voyager spacecraft back online.

On Dec. 12, 2023, NASA shared some worrisome news about Voyager 1, the first probe to walk away from our solar system 's gravitational party and enter the isolation of interstellar space . Surrounded by darkness, Voyager 1 seems to be glitching. 

It has been out there for more than 45 years, having supplied us with a bounty of treasure like the discovery of two new moons of Jupiter, another incredible ring of Saturn and the warm feeling that comes from knowing pieces of our lives will drift across the cosmos even after we're gone. (See: The Golden Record .) But now, Voyager 1 's fate seems to be uncertain.

As of Feb. 6, NASA said the team remains working on bringing the spacecraft back to proper health. "Engineers are still working to resolve a data issue on Voyager 1," NASA's Jet Propulsion Laboratory said in a post on X (formerly Twitter). "We can talk to the spacecraft, and it can hear us, but it's a slow process given the spacecraft's incredible distance from Earth."

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

So, on the bright side, even though Voyager 1 sits so utterly far away from us, ground control can actually communicate with it. In fact, last year, scientists beamed some software updates to the spacecraft as well as its counterpart, Voyager 2 , from billions of miles away. Though on the dimmer side, due to that distance, a single back-and-forth communication between Voyager 1 and anyone on Earth takes a total of 45 hours. If NASA finds a solution, it won't be for some time .

The issue, engineers realized, has to do with one of Voyager 1's onboard computers known as the Flight Data System, or FDS. (The backup FDS stopped working in 1981.)

"The FDS is not communicating properly with one of the probe's subsystems, called the telemetry modulation unit (TMU)," NASA said in a blog post. "As a result, no science or engineering data is being sent back to Earth." This is of course despite the fact that ground control can indeed send information to Voyager 1, which, at the time of writing this article , sits about 162 AU's from our planet. One AU is equal to the distance between the Earth and the sun , or 149,597,870.7 kilometers (92,955,807.3 miles).

Get the Space.com Newsletter

Breaking space news, the latest updates on rocket launches, skywatching events and more!

From the beginning 

Voyager 1's FDS dilemma was first noticed last year , after the probe's TMU stopped sending back clear data and started procuring a bunch of rubbish. 

As NASA explains in the blog post, one of the FDS' core jobs is to collect information about the spacecraft itself, in terms of its health and general status. "It then combines that information into a single data 'package' to be sent back to Earth by the TMU," the post says. "The data is in the form of ones and zeros, or binary code." 

However, the TMU seemed to be shuffling back a non-intelligible version of binary code recently. Or, as the team puts it, it seems like the system is "stuck." Yes, the engineers tried turning it off and on again. 

That didn't work. 

— SpaceX's Starship to launch 'Starlab' private space station in late 2020s

— Wonder what it's like to fall into Uranus? These scientists do, too

— Scientists' predictions for the long-term future of the Voyager Golden Records will blow your mind

Then, in early February, Suzanne Dodd, Voyager project manager at NASA's Jet Propulsion Laboratory, told Ars Technica that the team might have pinpointed what's going on with the FDS at last. The theory is that the problem lies somewhere with the FDS' memory; there might be a computer bit that got corrupted. Unfortunately, though, because the FDS and TMU work together to relay information about the spacecraft's health, engineers are having a hard time figuring out where exactly the possible corruption may exist. The messenger is the one that needs a messenger.

They do know, however, that the spacecraft must be alive because they are receiving what's known as a "carrier tone." Carrier tone wavelengths don't carry information, but they are signals nonetheless, akin to a heartbeat. It's also worth considering that Voyager 1 has experienced problems before, such as in 2022 when the probe's "attitude articulation and control system" exhibited some blips that were ultimately patched up. Something similar happened to Voyager 2 during the summer of 2023, when Voyager 1's twin suffered some antenna complications before coming right back online again.

Still, Dodd says this situation has been the most serious since she began working on the historic Voyager mission.

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].

Monisha Ravisetti is Space.com's Astronomy Editor. She covers black holes, star explosions, gravitational waves, exoplanet discoveries and other enigmas hidden across the fabric of space and time. Previously, she was a science writer at CNET, and before that, reported for The Academic Times. Prior to becoming a writer, she was an immunology researcher at Weill Cornell Medical Center in New York. She graduated from New York University in 2018 with a B.A. in philosophy, physics and chemistry. She spends too much time playing online chess. Her favorite planet is Earth.

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

NASA's Voyager 1 probe in interstellar space can't phone home (again) due to glitch

'Transformers One' 1st trailer unveils Optimus Prime and Megatron's shared history (video)

• Classical Motion There must be more to this story. Let me see if I have this right. They can receive a carrier. But the modulator gives them junk. Or possibly the processor's memory. And they can send new software. New instructions. So, why not simply use the packet data, to key the carrier on and off. OOK On and Off Keying. Telegraphy. Reply

Admin said: NASA's Voyager 1 deep space probe started glitching last year, and scientists aren't sure they can fix it. NASA's interstellar Voyager 1 spacecraft isn't doing so well — here's what we know : Read more

• Classical Motion I wish something would kick one of them back to us. I would love to see an analysis of every cubic cm of it. Reply
• billslugg Modulating the carrier wave would do no good unless the carrier knew what information to send us. The unit that failed takes the raw data and then tells the carrier what to say. Without the modulation unit there is no data to send. Reply

Classical Motion said: I wish something would kick one of them back to us. I would love to see an analysis of every cubic cm of it.

• Classical Motion I read that they were not sure if it was the modulator or the packet memory. The packet buffer. If they can send patch, it's easy to relocate that buffer into another section of memory. This can be done at several different memory locations to verify if it is a memory problem. If that works, then the modulator is ok. If the modulator fails with all those buffers, then it's the modulator. Turn off modulator. Just enable the carrier for a certain duration for a 1 bit. And turn it off for that certain duration for a 0 bit. One simply rotates that buffer string thru the accumulator at the duration rate, and use status flags to key the transmitter. Very simple and very short code. The packet is nothing more that a 128 BYTE or multiple size string of 1s and 0s. OOK is a very common wireless modulation. That's why I commented on more must be going on. And I would like to see what 30 years naked in space does to man molded matter. Reply

Classical Motion said: I read that they were not sure if it was the modulator or the packet memory. The packet buffer. If they can send patch, it's easy to relocate that buffer into another section of memory. This can be done at several different memory locations to verify if it is a memory problem. If that works, then the modulator is ok. If the modulator fails with all those buffers, then it's the modulator. Turn off modulator. Just enable the carrier for a certain duration for a 1 bit. And turn it off for that certain duration for a 0 bit. One simply rotates that buffer string thru the accumulator at the duration rate, and use status flags to key the transmitter. Very simple and very short code. The packet is nothing more that a 128 BYTE or multiple size string of 1s and 0s. OOK is a very common wireless modulation. That's why I commented on more must be going on. And I would like to see what 30 years naked in space does to man molded matter.

• damienassurre I think they should make another space craft and have it pick up voyager 1 and bring it back the info it went through would very valuable to stellar travel Reply

damienassurre said: I think they should make another space craft and have it pick up voyager 1 and bring it back the info it went through would very valuable to stellar travel

• billslugg The newer forms of memory can't be used easily in outer space as their feature size is too small and too easily corrupted by a cosmic ray. Very large, bulky features keep spacecraft memory far smaller than what earthbound computers can enjoy. As far as returning one of the Voyagers to Earth, it would take several thousand years using available technology. Better to wait for more advanced propulsion technologies. Reply
• View All 20 Comments

Most Popular

• 2 SpaceX launching Starlink satellites today on company's 40th mission of 2024
• 3 Sorry, little green men: Alien life might actually be purple
• 4 Zack Snyder on sticking the landing for the 2nd half of Netflix's 'Rebel Moon' (exclusive)
• 5 Russia launches new Angara A5 heavy-lift rocket on 4th orbital test mission (photos)

NASA's Voyager 1 sends readable message to Earth after 4 nail-biting months of gibberish

After four months of being unable to detect comprehensible data from the Voyager 1 spacecraft, NASA scientists have had fresh luck after sending a "poke."

After a nail-biting four months, NASA has finally received a comprehensible signal from its Voyager 1 spacecraft. 

Since November 2023, the almost-50-year-old spacecraft has been experiencing trouble with its onboard computers. Although Voyager 1, one of NASA's longest-lived space missions, has been sending a steady radio signal to Earth, it hasn't contained any usable data , which has perplexed scientists. 

Now, in response to a command prompt, or "poke," sent from Earth on March 1, NASA has received a new signal from Voyager 1 that engineers have been able to decode. Mission scientists hope this information may help them explain the spacecraft's recent communication problems. 

"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," NASA said in a blog post Wednesday (March 13) .

Related: NASA's 46-year-old Voyager 1 probe is no longer transmitting data

On March 1, as part of efforts to find a solution to Voyager 1's computer issues, NASA sent a command to the FDS on the spacecraft, instructing it to use different sequences in its software package, which would effectively mean skirting around any data that may be corrupted. 

Voyager 1 is more than 15 billion miles (24 billion kilometers) from Earth. This means any radio signals sent from our planet take 22.5 hours to reach the spacecraft, with any response taking the same time to be picked up by antennas on Earth. 

Sign up for the Live Science daily newsletter now

Get the world’s most fascinating discoveries delivered straight to your inbox.

On March 3, NASA detected activity from one section of the FDS that differed from the "unreadable data stream" they'd previously been receiving. Four days later, engineers started the heavy task of trying to decode this signal. By March 10, the team discovered that the signal contained a readout of the entire FDS memory. This included the instructions for what the FDS needed to do, any values in its code that can be changed depending on commands from NASA or the spacecraft's status, and downloadable science or engineering data.  

Voyager 1 has ventured farther from Earth than any other human-made object . It was launched in 1977, within weeks of its twin spacecraft , Voyager 2. The initial aim of the mission was to explore Jupiter and Saturn . Yet after almost five decades, and with countless discoveries under their belts, the mission continues beyond the boundaries of the solar system . 

— NASA hears 'heartbeat' signal from Voyager 2 probe a week after losing contact

— Historic space photo of the week: Voyager 2 spies a storm on Saturn 42 years ago

— NASA reestablishes full contact with Voyager 2 probe after nail-biting 2-week blackout

NASA scientists will now "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," they said in the blog post.  

However, NASA stressed that it will take time to determine if any of the insights gained from this new signal can be used to solve Voyager 1's long-standing communication issues. 

Emily is a health news writer based in London, United Kingdom. She holds a bachelor's degree in biology from Durham University and a master's degree in clinical and therapeutic neuroscience from Oxford University. She has worked in science communication, medical writing and as a local news reporter while undertaking journalism training. In 2018, she was named one of MHP Communications' 30 journalists to watch under 30. ( [email protected] ) 

NASA's downed Ingenuity helicopter has a 'last gift' for humanity — but we'll have to go to Mars to get it

Object that slammed into Florida home was indeed space junk from ISS, NASA confirms

'Uncharted territory': El Niño to flip to La Niña in what could be the hottest year on record

• Bruzote I have an inside source who says the message said, "Be sure to drink your Ovaltine." Reply
• Grumpy-DC I love Ovaltine. Both flavors. And I remember "Captain Midnight" sponsored by same. Reply

Grumpy-DC said: I love Ovaltine. Both flavors. And I remember "Captain Midnight" sponsored by same.

• View All 3 Comments

Most Popular

• 2 The universe may be dominated by particles that break causality and move faster than light, new paper suggests
• 3 Nightmare fish may explain how our 'fight or flight' response evolved
• 4 Intel unveils largest-ever AI 'neuromorphic computer' that mimics the human brain
• 5 Lyrid meteor shower 2024: How to watch stunning shooting stars and 'fireballs' during the event's peak this week
• 2 Intel unveils largest-ever AI 'neuromorphic computer' that mimics the human brain
• 3 50-foot 'king of the serpents' may have been the biggest snake to ever live
• 4 Scientists are one step closer to knowing the mass of ghostly neutrinos — possibly paving the way to new physics
• 5 Watch tigress and her cubs feasting on crocodile they killed in rare footage

• The Contents
• The Making of
• Where Are They Now
• Frequently Asked Questions
• Q & A with Ed Stone

golden record

Where are they now.

• frequently asked questions
• Q&A with Ed Stone

Galleries of Images Voyager Took

The Voyager 1 and 2 spacecraft explored Jupiter, Saturn, Uranus and Neptune before starting their journey toward interstellar space. Here you'll find some of those iconic images, including "The Pale Blue Dot" - famously described by Carl Sagan - and what are still the only up-close images of Uranus and Neptune.

Photography of Jupiter began in January 1979, when images of the brightly banded planet already exceeded the best taken from Earth. Voyager 1 completed its Jupiter encounter in early April, after taking almost 19,000 pictures and many other scientific measurements. Voyager 2 picked up the baton in late April and its encounter continued into August. They took more than 33,000 pictures of Jupiter and its five major satellites.

The Voyager 1 and 2 Saturn encounters occurred nine months apart, in November 1980 and August 1981. Voyager 1 is leaving the solar system. Voyager 2 completed its encounter with Uranus in January 1986 and with Neptune in August 1989, and is now also en route out of the solar system.

NASA's Voyager 2 spacecraft flew closely past distant Uranus, the seventh planet from the Sun, in January. At its closet, the spacecraft came within 81,800 kilometers (50,600 miles) of Uranus's cloudtops on Jan. 24, 1986. Voyager 2 radioed thousands of images and voluminous amounts of other scientific data on the planet, its moons, rings, atmosphere, interior and the magnetic environment surrounding Uranus.

In the summer of 1989, NASA's Voyager 2 became the first spacecraft to observe the planet Neptune, its final planetary target. Passing about 4,950 kilometers (3,000 miles) above Neptune's north pole, Voyager 2 made its closest approach to any planet since leaving Earth 12 years ago. Five hours later, Voyager 2 passed about 40,000 kilometers (25,000 miles) from Neptune's largest moon, Triton, the last solid body the spacecraft will have an opportunity to study.

This narrow-angle color image of the Earth, dubbed 'Pale Blue Dot', is a part of the first ever 'portrait' of the solar system taken by Voyager 1. The spacecraft acquired a total of 60 frames for a mosaic of the solar system from a distance of more than 4 billion miles from Earth and about 32 degrees above the ecliptic. From Voyager's great distance Earth is a mere point of light, less than the size of a picture element even in the narrow-angle camera. Earth was a crescent only 0.12 pixel in size. Coincidentally, Earth lies right in the center of one of the scattered light rays resulting from taking the image so close to the sun. This blown-up image of the Earth was taken through three color filters -- violet, blue and green -- and recombined to produce the color image. The background features in the image are artifacts resulting from the magnification.

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]

NASA Decodes the Reason Behind Voyager 1's Garbled Transmissions

For months, NASA's Voyager team has been struggling to translate garbled messages from beyond our solar system. Voyager 1 has been responding to NASA's data requests with tangles of 1s and 0s, none of which have made sense to anyone at the agency. But now, thanks to a "poke command" issued in March, the spacecraft seems to have helped scientists identify the error behind its wonky transmissions. 

NASA had just managed to solve an issue with Voyager 1's attitude articulation and control system (AACS) in 2022 when a new glitch arose, jumbling the probe's flight data. This raw data is supposed to convey information about what Voyager 1's various scientific instruments have gleaned from remote regions of the Milky Way, but instead, it was just a mysterious stream of unintelligible numbers. Getting the spacecraft to return to its original "language" has been a challenge ever since, in part because most of the folks who originally worked on Voyager 1 are no longer alive .

In March, NASA sent Voyager 1 a poke command, or a command that directly modifies a system's memory addresses. Though poke commands are a fairly antiquated concept, they're occasionally useful for low-level memory control—a stone the Voyager team couldn't leave unturned. Their command prompted Voyager 1's system into using a different readout sequence for its software package than it typically defaults to, and about 22 hours later, NASA found itself with a new clue.

According to a Voyager mission blog post , activity from one portion of Voyager 1's flight data system (FDS) stood out from the probe's previous unreadable transmissions. A single engineer involved in NASA's Deep Space Network saw that the data contained a readout of Voyager 1's full FDS memory. This, the engineer noticed, offered the team an opportunity to compare and contrast Voyager 1's previous FDS readout with the latest snapshot of its inner workings.   

NASA has since used the decoded readout to determine that roughly 3 percent of the probe's memory is corrupted. This may explain why restarting the FDS didn't resolve the issue back in November: If a system's memory has degraded, turning that system off and back on again won't do anything to bring it back. Luckily, engineers at the Voyager mission think the corruption is confined to just one chip, which could make the issue easier to circumvent or resolve.