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Go Voyager

It’s worth thinking about why Voyager 1 and 2, now coming up on their 40th year of operation, are still sending back data. After all, mission longevity becomes increasingly important as we anticipate missions well outside the Solar System, and the Voyagers are giving us a glimpse of what can be done even with 1970’s technology. We owe much of their staying power to their encounters with Jupiter, which demanded substantial protection against the giant planet’s harsh radiation, a design margin still used in space missions today.

The Voyagers were the first spacecraft to be protected against external electrostatic charges and the first with autonomous fault protection, meaning each spacecraft had the ability to detect problems onboard and correct them. We still use the Reed-Solomon code for spacecraft data to reduce data transmission errors, and we all benefited from Voyager’s programmable attitude and pointing capabilities during its planetary encounters.

Pioneer 6 was a doughty vehicle, but Voyager 2 (launched before Voyager 1) passed its record as longest continuously operating spacecraft back in August of 2012, while Voyager 1 eclipsed Pioneer 10’s distance mark in 1998 and is now traveling some 21 billion kilometers out. Voyager 1 is our sole spacecraft to leave the heliosphere, though Voyager 2 is expected to follow it in a few years, and we’ve already acquired important information, such as the fact that cosmic rays are four times more abundant in interstellar space than near the Earth.

You can see how all this begins to build the foundation for a ‘true’ interstellar mission, by which I mean one designed solely for the purpose of penetrating the local interstellar medium and reporting data from it. The heliosphere, Voyager has shown us, wraps around our Solar System and helps to provide a radiation shield for the planets. Missions both robotic and manned will need to be designed around the cosmic ray issues Voyager has uncovered.

Image: Voyager 1 image of Io showing active plume of Loki on limb. Heart-shaped feature southeast of Loki consists of fallout deposits from active plume Pele. The images that make up this mosaic were taken from an average distance of approximately 490,000 kilometers. Credit: NASA/JPL/USGS.

Still thinking interstellar, the Voyagers are telling us about the solar wind’s termination shock, that region where charged particles from the Sun slow to below the speed of sound as they push out into the interstellar medium — these are Voyager 2 measurements. Voyager 1 has measured the density of the interstellar medium as well as magnetic fields outside the heliosphere. The final benefit: We’ll have Voyager 2 outside the heliosphere while still in communication, so we can sample the interstellar medium from two different locations.

I always think of long spacecraft missions in terms of the people who work on them. Voyager is pushing on the ‘lifetime of a researcher’ rubric that some consider essential (though I disagree), the notion that missions have to be flown so that those who worked on them can see them through to destination. But of course the Voyagers have no destination as such; they’ll press on in a galactic orbit that takes fully 225 million years to complete. And as our spacecraft get even more rugged and capable of autonomy, we’ll soon take it as a given that multiple generations will be involved in seeing any complex mission through to completion. (See Voyager to a Star for my riff on a symbolic ‘extension’ to the Voyager mission).

Image: These two pictures of Uranus — one in true color (left) and the other in false color — were compiled from images returned Jan. 17, 1986, by the narrow-angle camera of Voyager 2. The spacecraft was 9.1 million kilometers from the planet, several days from closest approach. The picture at left has been processed to show Uranus as human eyes would see it from the vantage point of the spacecraft. Credit: NASA/JPL.

We have, according to the Jet Propulsion Laboratory, perhaps until 2030 before data from the Voyagers ceases. Each spacecraft contains three radioisotope thermoelectric generators (RTGs) running off the decay of plutonium-238. And as this JPL news release reminds us, with the spacecraft power decreasing by four watts per year, engineers have to be creative at figuring out how best to squeeze out data results under extreme power constraints.

For a mission this long, that means consulting documents written decades ago and at a completely different stage of technological development.

“The technology is many generations old, and it takes someone with 1970s design experience to understand how the spacecraft operate and what updates can be made to permit them to continue operating today and into the future,” said Suzanne Dodd, Voyager project manager based at NASA’s Jet Propulsion Laboratory in Pasadena.

Image: Global color mosaic of Triton, taken in 1989 by Voyager 2 during its flyby of the Neptune system. Triton is one of only three objects in the Solar System known to have a nitrogen-dominated atmosphere (the others are Earth and Saturn’s giant moon, Titan). The greenish areas include what is called the cantaloupe terrain, whose origin is unknown, and a set of “cryovolcanic” landscapes apparently produced by icy-cold liquids (now frozen) erupting from Triton’s interior. Credit: NASA/JPL/USGS.

It’s been quite a ride. Voyager discovered Io’s volcanoes and imaged rings around Jupiter, Uranus and Neptune, while finding hints of the apparent ocean within Europa that carries so much astrobiological interest. Between them, the Voyagers found a total of 24 new moons amongst the four planets they visited, detecting lightning on Jupiter and a nitrogen-rich atmosphere at Titan, the first to be found outside the Earth itself. And who can forget that bizarre terrain on Triton, or the tortured surface of Uranus’ moon Miranda?

“None of us knew, when we launched 40 years ago, that anything would still be working, and continuing on this pioneering journey,” said Ed Stone, Voyager project scientist based at Caltech in Pasadena, California. “The most exciting thing they find in the next five years is likely to be something that we didn’t know was out there to be discovered.”

Image: The Voyagers outbound. A representation of the heliosphere, including the termination shock (TS), the heliopause and the interstellar medium where the heliosphere ends. Credit: Science, NASA/JPL-California Institute of Technology. Note: In this image, the locations of the Voyagers are updated only to September 2011, by Brad Baxley, JILA.

Who knew that Voyager’s measurements of solar wind plasma, low-frequency radio waves, charged particles and magnetic fields would still be informing us fully forty years on? The next spacecraft to cross the heliosphere after Voyager, this time designed for just that purpose, will surely live even longer, challenging our conceptions of human achievement across generations and our willingness to tackle projects involving not just deep space but deep time.

This mission isn’t over. Go Voyager.


{ 37 comments… add one }
  • Michael Spencer August 2, 2017, 9:19

    Thank you, Paul, for this lovely — and loving — look at Voyager’s mission.

  • jonW August 2, 2017, 11:42

    Great post. Could you explain what “speed of sound” means in this context: “that region where charged particles from the Sun slow to below the speed of sound as they push out into the interstellar medium”?

    • jonW August 2, 2017, 15:39

      By which I meant–sorry–is it just that the particles slow to below ~343 m/s, or is there some meaning to the speed of sound (it would have to be *extremely* low-frequency sound) in the interstellar medium, which is almost, but not quite, a vacuum?

      • Paul Gilster August 2, 2017, 16:01

        I assume this does indeed mean extremely low-frequency sound through a medium that is not a perfect vacuum. 343 m/s is the speed of sound in the atmosphere under specific conditions.

    • Paul Gilster August 2, 2017, 15:41

      Corrections welcomed because this is just a quick take on the matter, and there are those here who can explain it far better than I: The solar wind — charged particles from the Sun moving at high velocity — encounters the interstellar medium (varying densities of gas and dust) as it nears the ‘termination shock.’ Eventually the pressure of the ‘wind’ drops below supersonic flow as measured against the pressure of the medium. The figure I’ve seen for this ‘speed of sound’ value is about 100 km/s, but it varies depending on the density of the medium. The heliopause is where the interstellar medium and solar wind pressures balance.

      • Marshall Eubanks August 2, 2017, 20:38

        The solar wind plasma is dominated by the Sun’s magnetic field, and so the analog to sound (pressure) waves in air are Alfven waves in the plasma. When scientists talk about supersonic or subsonic flows in the solar wind, heliopause, etc., they are comparing the flow speed to the local Alfven velocity, v_A, which is ~ B / sqrt(mu_0 rho), where B is the field strength, mu_0 the permeability of the vacuum and rho the mass density of the plasma. At 1 AU (near the Earth, but outside its magnetosphere), v_A is about 35 km/sec while typical flow speeds are maybe 400 km/sec. Such flows are described as supersonic, with a Mach number of order 12, but this is in reference to v_A.

        • Paul Gilster August 3, 2017, 7:54

          Excellent, Marshall. I knew one of the readers would have a much more insightful take on this issue. Thanks!

  • ljk August 2, 2017, 11:44

    An Irish documentary about the incredible Voyager spacecraft is getting huge praise:


    To quote:

    Beyond the topic at hand, what’s particularly striking about The Farthest is the number of women who worked on it. I ask Reynolds about this, and how it may tie into the recent moves by the Irish Film Board to address gender imbalance in Ireland’s film industry.

    “It’s wonderful now to see, the change is so positive and it’s so dynamic. And it’s a real turning of the wheel, which I really applaud,” says Reynolds of the deliberate steps to bring about gender parity. Over the years she worked as a film editor, just a “minuscule fraction” of the directors she worked with were women.

    “Encouraging women into key positions is fantastic for everyone,” she says. The film itself reflects that.

    “We took it as read that women’s voices would be loud and proud in it,” says Reynolds. This also reflects the growth in acknowledgement of women’s role in scientific discoveries, such as the film Hidden Figures.

    After the documentary was shown at the Audi Dublin International Film Festival, Reynolds got three letters from young girls (two aged 10 and one aged 12) telling her they want to be scientists.

    “I was like, ‘my work is done’,” says Reynolds. “That was the thrill of a lifetime, for me to inspire them.”

  • ljk August 2, 2017, 11:46

    ‘It’s a romantic attempt to describe how we are as humans to an extra-terrestrial audience’

    Emer Reynolds’s new film ‘The Farthest’ looks at the extraordinary, humbling story the Voyager space project.

    Sat, July 29, 2017, 05:00


    To quote:

    Interestingly, the Voyager crew have mixed feelings about the famous “golden record” that each craft carries. This is a gold-plated copper LP, packed with a needle, cartridge and instructions, and containing, in groove form, photos from Earth, a selection of natural sounds, plus music from a variety of cultures and eras. Tracks include Chuck Berry’s Johnny B Goode, Glenn Gould performing from Bach’s Well-Tempered Clavier, and a pygmy girl’s initiation song from Zaire.

    Carl Sagan, the project supervisor and astrophysicist, had wanted to include The Beatles’ Here Comes the Sun, but EMI turned him down, saying “We don’t licence for outer space.” There are, additionally, spoken greetings in 55 languages, including such ancient dialects as Akkadian and Hittite. The Amoy message asks: “Friends of space, how are you all? Have you eaten yet? Come visit us if you have time.” Nick Sagan, the Star Trek writer and son of Carl Sagan, recorded the English message as a child: “Hello from the children of planet Earth.”

    “I think one of the great things about Voyager is that it just naturally has these two pieces to it,” says Reynolds. “The heart and the mind. It combines extraordinary scientific discoveries and achievement with this romantic attempt to describe how we are as humans to an extra-terrestrial audience. This little craft built in the 1970s is knocking it out of the park in terms of science. But it also has this amazing golden record attached to the outside of the craft which is insane that is trying to communicate with aliens. It has everything we are as people.”

  • Gary Wilson August 2, 2017, 11:55

    A truly historic mission of the highest caliber.

  • Alex Tolley August 2, 2017, 13:01

    “The technology is many generations old, and it takes someone with 1970s design experience to understand how the spacecraft operate and what updates can be made to permit them to continue operating today and into the future,”

    The plot justification for the movie “Space Cowboys”.

    Voyager is pushing on the ‘lifetime of a researcher’ rubric that some consider essential (though I disagree), the notion that missions have to be flown so that those who worked on them can see them through to destination.

    I don’t think that is quite true. The mission doesn’t have to be seen all the way through, but it must do something for the career of the researchers during their lifetimes. Voyager certainly did that, even as it continues to generate new data for new researchers. If the Voyagers had not made all those observations as they traveled from planet to planet but only now were generating data on a dedicated mission to the heliopause, then I would suggest that such a mission would not have been done. If that was acceptable, we could, theoretically, follow up with such missions today. Instead, we are looking for propulsion technologies to get probes there a lot faster so that results can be analyzed by the science team within their career lives.Breakthrough starshot offers just such a technology. Sending many small probes to map the boundaries of Sol and the nearby interstellar medium would be quite achievable, with rich maps produced within a very short time. It could be as perspective changing as the first satellite images of Earth.

    • Manny August 3, 2017, 2:07

      I agree with Paul’s take on the matter. The reason for needing someone with 1970s design experience to squeeze every ounce of power out of the Voyagers is that the probes were never designed to travel to the interstellar medium. The fact that they have had such a long and productive life is truly a testament to those who worked on them.
      That being said, I do not believe a mission that stayed within its original design parameters for its entire duration (be it 10-100+ years) would run into such problems. The farther out we go, the more it becomes clear that space exploration is a generational endeavor.

    • NS August 3, 2017, 4:41

      A possible mission to near interstellar space using current technology (Innovative Interstellar Explorer) was described here on Centauri Dreams a few years ago:


      It would have a 30 year flight time to 200 a.u. Launch windows occur every 12 years because the proposed mission uses a gravity sling around Jupiter.

      Unfortunately for me, even if IIE launches in the next available window (2026) I’ll be 100 years old when it gets to 200 a.u., so I’m certainly interested in faster alternatives!

      • ljk August 7, 2017, 10:30

        Take more than a little comfort in knowing that your descendants among many others will benefit from such a mission. Too many other things in modern society are so transient.

  • Rob Flores August 2, 2017, 13:04

    I picture the far future where it takes only days to get to
    a Pluto orbit, as part of a Solar System Safari, you get
    to rendezvous with VOYAGER.
    Not only that as your ship matches speed,
    It will be brought into a large cargo bay where you may lay hands
    on it, a mobile Stonehenge if you will.

    At first only the very wealth would afford it,
    after a few centuries, it will be a required field
    trip for young students.

    • ljk August 2, 2017, 15:20

      You will probably get a kick out of this future scenario for Voyager 1 from Orion’s Arm:


    • Antonio August 2, 2017, 15:22

      “I picture the far future where it takes only days to get to
      a Pluto orbit, as part of a Solar System Safari, you get
      to rendezvous with VOYAGER.”

      Unless you had adamantium bones, you would be pretty dead by then–unless by “only days” you meant a couple of months.

      • Rob Flores August 2, 2017, 16:05

        Antonio, trying to be poetic but.

        Granted at 3 g acceleration in six days, gets you in the ball park of Neptune orbit.

        The future has a ship with all that acceleration and military
        aps people haven’t solved the High G obstacle? unthinkable.
        Civilian application usually follows military ones.

        • Antonio August 2, 2017, 16:41

          I think it’s quite more than 3 g. This was my back of the envelope calculation:

          Pluto is 5.5 light-hours from the Sun. If you want to reach it in “only days” you need, say, 0.1 c. To reach 0.1 c at 1 g it would take around a month, but, since you will do Pluto orbit insertion, you would need to decelerate, so that would be 2-3 months at 1 g. If you want to accomplish the same trip in only days instead of 2-3 months, you will experience acceelerations in the order of 20-30 g or so during days. You would be carrying the weight of 20-30 people during days.

  • ljk August 2, 2017, 15:30

    Not that I am complaining, but I thought that the Voyager probes would run out of useful power by 2025, not 2030. When did this date change?

    Regarding Pioneer 6, token contact was made with the satellite in 2000, but has anyone checked since? Wikipedia says of all the members of this particular group of Pioneers, only Number 9 is definitely no longer functional. The rest (6, 7, and 8) may still be reachable. It would be nice if someone tried, especially if they have still been collecting solar data since the late 1960s!

    • Paul Gilster August 2, 2017, 15:43

      I’m beginning to see 2030 as a terminus, assuming all but one instrument on each spacecraft turned off.

    • J. Jason Wentworth August 3, 2017, 4:51

      The Sun-orbiting Pioneers (6, 7, and 8) interest me as well. So do ISEE-3 and Giotto (which–if memory serves–was placed in hibernation after its second comet encounter, with Grigg-Skjellerup in 1992). All five of these spacecraft (and perhaps others in solar orbit) might possibly still be active (or “awaken-able”), and if so, they could return solar data, and:

      Both Pioneer 7 (which made a distant flyby) and Pioneer 12 (the now-gone Pioneer Venus Orbiter, which took measurements and images from afar), investigated Halley’s Comet (in fact, a 1974 Hughes Aircraft booklet on the then-upcoming Pioneer Venus mission proposed using spacecraft of the orbiter’s design for solar-orbiting comet flyby spacecraft). With so many short-period comets–and the occasional long-period one–crisscrossing the inner solar system, the old solar-orbiting spacecraft may pass close enough to some of them to gather useful data. Using these old spacecraft for this would be a cheap way to acquire new knowledge about never-before-visited comets.

  • Antonio August 2, 2017, 17:51

    “Voyager is pushing on the ‘lifetime of a researcher’ rubric that some consider essential (though I disagree), the notion that missions have to be flown so that those who worked on them can see them through to destination.”

    Well, ‘lifetime of a researcher’ is not a constant at all. Life expectancy has been increasing at a quite constant pace of around 3 months per year in the developed world for quite a long time now. For example, in the US, male life expectancy in 2013 was 9 years longer than in 1973.

    • Andrei August 5, 2017, 2:58

      Not only ‘Lifetime of a researcher’ is necessary but funding. I am sorry many do not understand how research work is done and funded.

      Profit run research coporation: Your project will not even get started.

      Private research institute: You have to apply for funds for your research project, it have to compete with proposal with close or immediate results. Your proposal will never get granted.

      Government institute/university: The project to build a probe to fly for generations could be started, but a scientific career is built on the published results, without result you’ll be seen as failure and loose funding. It will not be finished if it’s not one closer goal to reach.
      (Blue sky research is now unusual, trend is to have immediate application. We have found something new and unexpected, but we do not have funds in 2018-2022 period or perhaps ever, and we cannot finish the studywork properly.)

      Sorry I digress. But this the reason there is 2 more missions to asteroids now instead of Uranus and Neptune & Triton (or Titan). Long lasting daring missions do not get approval.

  • andy August 3, 2017, 4:17

    Triton is one of only three objects in the Solar System known to have a nitrogen-dominated atmosphere (the others are Earth and Saturn’s giant moon, Titan)

    Don’t forget (134340) Pluto!

  • Damian Schiavo August 3, 2017, 15:00

    It took 40 years for simple and wonderful automatic probes to slowly reach the solar wind border in our star system …
    Only now (see last image) the probes begin to feel the wind … the wind of the stars of the galaxy …
    I like to imagine how many “pietas” …THEY look at us amused and silent, waiting for us to invent a futuristic technology that allows us to move between the stars ….
    As other civilizations already make millions or billions of years, even without metal hulls …

  • ljk August 4, 2017, 9:36

    The Loyal Engineers Steering NASA’s Voyager Probes Across the Universe

    As the Voyager mission is winding down, so, too, are the careers of the aging explorers who expanded our sense of home in the galaxy.


    AUG. 3, 2017

    In the early spring of 1977, Larry Zottarelli, a 40-year-old computer engineer at NASA’s Jet Propulsion Laboratory in Pasadena, set out for Cape Canaveral, Fla., in his Toyota Corolla. A Los Angeles native, he had never ventured as far as Tijuana, but he had a per diem, and he liked to drive. Just east of Orlando, a causeway carried him over the Indian and Banana Rivers to a triangular spit of sand jutting into the Atlantic, where the Air Force keeps a base. His journey terminated at a cavernous military hangar.

    A fleet of JPL trucks made the trip under armored guard to the same destination. Their cargo was unwrapped inside the hangar high bay, a gleaming silo stocked with tool racks and ladder trucks. Engineers began to assemble the various pieces. Gradually, two identical spacecraft took shape. They were dubbed Voyager I and II, and their mission was to make the first color photographs and close-up measurements of Jupiter, Saturn and their moons. Then, if all went well, they might press onward — into uncharted territory.

    It took six months, working in shifts around the clock, for the NASA crew to reassemble and test the spacecraft. As the first launch date, Aug. 20, drew near, they folded the camera and instrument boom down against the spacecraft’s spindly body like a bird’s wing; gingerly they pushed it, satellite dish first, up inside a metal capsule hanging from the high bay ceiling. Once ‘‘mated,’’ the capsule and its cargo — a probe no bigger than a Volkswagen Beetle that, along with its twin, had nevertheless taken 1,500 engineers five years and more than $200 million to build — were towed to the launchpad.

    Full article here:


    To quote:

    They relieved stress with games and pranks: bowling in the hallway, using soda cans as pins; filling desk drawers with plastic bags of live goldfish; making scientists compete in disco-pose contests. Now, by 1990, they were older, with kids of their own. They had experienced the deaths of colleagues and watched others’ marriages falter as a result of long hours at the lab. With no planets to explore, they spent the decade doing routine spacecraft maintenance with a fraction of their bygone manpower. Six of the current nine engineers were on the team then. Sun Kang Matsumoto, who joined the mission in ’85, studied so diligently to master the new roles pressed upon her that her sons learned the spacecraft contours by osmosis. When her eldest was 8, he surprised her with a perfect Lego model; now in college, ‘‘he calls and asks, ‘How is Voyager?’ Like, ‘How is Grandma?’ ’’ Matsumoto says.

  • ljk August 4, 2017, 10:27

    August 2, 2017

    Two Voyagers Taught Us How to Listen to Space

    As NASA’s twin Voyager spacecraft were changing our understanding of the solar system, they also spurred a leap in spacecraft communications.

    The mission’s impact is still visible in California’s Mojave Desert. There, at NASA’s Goldstone Deep Space Communications Complex, the arcs of antenna dishes peek out over craggy hilltops. Goldstone was the first place where the two Voyagers started to change the landscape. The farther they traveled, the bigger these dishes needed to be so they could send and receive radio waves necessary to track and communicate with the probes.

    Starting in the 1970s, construction crews built new dishes and expanded old ones. These dishes now tower over the desert: the largest is 230 feet (70 meters) in diameter, a true colossus. Its smaller siblings are 112 feet (34 meters) in diameter, longer than two school buses at their widest points. The dishes had to grow from their original 210 feet (64 meters) and 85 feet (26 meters), respectively.

    The expanded dish sizes were mirrored at NASA’s other Deep Space Network (DSN) sites, located in Madrid, Spain, and Canberra, Australia. The DSN is managed by NASA’s Jet Propulsion Laboratory in Pasadena, California, under the direction of the agency’s Space Communication and Navigation (SCaN) Program.

    The Voyager mission helped drive this evolution. Today, the Voyagers are more than 10 billion miles from Earth, and Voyager 1 has gone past the heliosphere — the bubble containing the Sun, the planets and the solar wind. The vast distances between the probes and Earth have required bigger and better “ears” with which to hear their increasingly faint signals.

    “In a sense, Voyager and the DSN grew up together,” said Suzanne Dodd of JPL, director of the Interplanetary Network Directorate and Voyager’s project manager since 2010. “The mission was a proving ground for new technology, both in deep space as well as on Earth.”

    Full article here:


    To quote:

    “Today, space agencies borrow antennas routinely to help each other, something which began with Voyager,” said Leslie Deutsch of JPL, deputy director of the Interplanetary Network Directorate. Deutsch helped research how to perform NASA’s first arrays and how to incorporate the non-DSN antennas into that work.

  • ljk August 4, 2017, 11:08

    NASA is doing a little METI for Voyager’s 40th anniversary:

    Send a #MessageToVoyager!


    And a new article on the Physical METI attached to the twin Voyager space probes:


    To quote:

    The big questions about alien life tend to ask some variation of “Are we alone in the universe?” Sagan’s team operated from the assumption that we aren’t, and asked instead how we might appear to our new alien friends in the best possible light. “Why not a hopeful rather than a despairing view of humanity and its possible future?” as Sagan wrote in Murmurs of Earth, his 1978 account of the making of the records. So even as the records contain feel-good scenes of humanity and nature (for example, a portrait of a woman in a floral dress breastfeeding a baby, and a shot of a field of flowers—deliberately chosen for their visual resonance), the team included no depictions of war, disease, poverty, environmental loss, anger, or loneliness. There is, of course, a hint of loneliness suggested by the very existence of the records—gold-plated invitations to potential friends. Like anyone looking to play host, we wanted to impress. But the decisions were more complicated than that. Images of war—and especially of weaponry—would have been too potentially ambiguous to risk. If this was our one chance to make contact, we had to get it right.

  • xcalibur August 5, 2017, 18:25

    The Voyager probes are a prime example of what we can accomplish with long-term thought and action. Even if the original designers never intended the mission to pay out dividends this long, we still owe all this to their rugged and reliable engineering work.

    As others have pointed out, our culture emphasizes the near-term. We want return on investment, and conclusions to publish within a few years. It’s not easy to surmount this, but maybe the example of the Voyagers will inspire us to allocate more resources towards the long-term.

  • ljk August 7, 2017, 10:43

    Why NASA’s Interstellar Mission Almost Didn’t Happen

    Launched 40 years ago, the Voyager space probes are on a grand tour of the cosmos that nearly ended at Saturn.

    By Timothy Ferris.

    This story appeared in the August, 2017 issue of National Geographic Magazine.

    Insofar as we esteem the creations that last—Homer’s Odyssey, the bridge still standing, enduring love—let us now praise the twin Voyager space probes, launched 40 years ago and currently departing the solar system to drift forever among the stars.

    Each about the size and weight of a subcompact automobile, the Voyagers epitomize 1970s high tech. Their computers are weaker than those in today’s digital watches, their analog TV cameras more primitive than the ones that shot Laverne & Shirley. But they made history at every planet they reconnoitered—confirming, as Voyager chief scientist Ed Stone put it, that “nature is much more inventive than our imaginations.”

    Full article here:


    To quote:

    The Voyagers paved the way for the Jupiter orbiter Galileo and the Saturn orbiter Cassini that followed, which spent years gathering photos and data before being ordered to incinerate themselves in the planets’ upper atmospheres to ensure that they’d never impact and contaminate a possibly life-harboring moon. Now the Voyagers as well are nearing the end of their scientific life. Their weakening radio signals, currently reporting on the surprisingly complex plasma bubble that surrounds the sun and marks the designated boundary between the solar system and interstellar space, are expected to fall silent around 2030, when the Voyagers’ plutonium-powered electrical generators finally falter.

    Thereafter the Voyagers will function more as time capsules than spaceships. With that eventuality in mind, JPL attached to each probe a copy of the “golden record” that contains music, photographs, and sounds of Earth for the benefit of any extraterrestrials who might intercept it someday. The records should remain playable for at least a billion years before succumbing to erosion from micrometeorites and the high-velocity subatomic particles called cosmic rays.

    That’s a long time. A billion years ago, the most complex forms of life on Earth were the tidewater mats of cyanobacteria called stromatolites. A billion years from now, the brightening sun shall have begun boiling off Earth’s oceans. Yet the Voyagers will still be out there somewhere, emissaries of a species that dispatched them without hope of return.

  • ljk August 7, 2017, 21:43

    The Voyagers have reached an anniversary worth celebrating

    New documentary shows the human and scientific drama behind the iconic spacecraft.

    ERIC BERGER – 8/7/2017, 7:15 AM


  • ljk August 7, 2017, 21:58

    Tipperary farm provided inspiration for hit space film

    9:00 am – August 7, 2017

    Caroline Allen

    A farm outside Mullinahone, Co. Tipperary, sowed the seeds of a fascination that led to the making of a documentary on the Voyager space programme, which has been receiving rave reviews around the globe.

    Emer Reynolds, director of the award-winning ‘The Farthest‘, told AgriLand how Mohober House’s night sky left her dazzled and “in awe of the visible smudge of our Milky Way galaxy overhead.”

    Reynolds, an Emmy-nominated multi-award winning documentary director and feature film editor, is the force behind ‘The Farthest.’

    Full article here:


    To quote:

    A fascination with space began on those farm stays. “Mohober House’s sky at night was the opposite to the skies over our home in Dublin. We would drive to Tipperary in our old Hillman Hunter, my dad doing maths puzzles with us all the way, just for fun.

    “As night fell, the dark, dark skies overhead would reveal the sparkling cosmos. I was dazzled and in awe of the visible smudge of our Milky Way Galaxy overhead.

    I would spend hours lying on the grass, staring into the blackness. I was dreaming of tumbling through space, hurtling along at 67,000 mph, clutching onto a fragile blue planet.

    “Aliens, horse-head nebula, star nurseries and time-travel, and exotic distant worlds filled my head as a child. They still do in fact.

    “The film is a love story to that awe and wonder I first felt as a child in Tipperary,” Reynolds said.

  • ljk August 15, 2017, 12:47


    Voyager Golden Records 40 years later: Real audience was always here on Earth

    August 13, 2017 10.33 pm EDT

    Forty years ago, NASA launched Voyager I and II to explore the outer solar system. The twin spacecraft both visited Jupiter and Saturn; from there Voyager I explored the hazy moon Titan, while Voyager II became the first (and, to date, only) probe to explore Uranus and Neptune. Since they move too quickly and have too little propellant to stop themselves, both spacecraft are now on what NASA calls their Interstellar Mission, exploring the space between the stars as they head out into the galaxy.

    Both craft carry Golden Records: 12-inch phonographic gold-plated copper records, along with needles and cartridges, all designed to last indefinitely in interstellar space. Inscribed on the records’ covers are instructions for their use and a sort of “map” designed to describe the Earth’s location in the galaxy in a way that extraterrestrials might understand.

    The grooves of the records record both ordinary audio and 115 encoded images. A team led by astronomer Carl Sagan selected the contents, chosen to embody a message representative of all of humanity. They settled on elements such as audio greetings in 55 languages, the brain waves of “a young woman in love” (actually the project’s creative director Ann Druyan, days after falling in love with Carl Sagan), a wide-ranging selection of musical excerpts from Blind Willie Johnson to honkyoku, technical drawings and images of people from around the world, including Saan Hunters, city traffic and a nursing mother and child.

    Since we still have not detected any alien life, we cannot know to what degree the records would be properly interpreted. Researchers still debate what forms such messages should take. For instance, should they include a star map identifying Earth? Should we focus on ourselves, or all life on Earth? Should we present ourselves as we are, or as comics artist Jack Kirby would have had it, as “the exuberant, self-confident super visions with which we’ve clothed ourselves since time immemorial”?

    But the records serve a broader purpose than spreading the word that we’re here on our blue marble. After all, given the vast distances between the stars, it’s not realistic to expect an answer to these messages within many human lifetimes. So why send them and does their content even matter? Referring to earlier, similar efforts with the Pioneer spacecraft, Carl Sagan wrote, “the greater significance of the Pioneer 10 plaque is not as a message to out there; it is as a message to back here.” The real audience of these kinds of messages is not ET, but humanity.

    In this light, 40 years’ hindsight shows the experiment to be quite a success, as they continue to inspire research and reflection.

    Only two years after the launch of these messages to the stars, “Star Trek: The Motion Picture” imagined the success of similar efforts by (the fictional) Voyager VI. Since then, there have been Ph.D. theses written on the records’ content, investigations into the identity of the person heard laughing and successful crowdfunded efforts to reissue the records themselves for home playback.

    The choice to include music has inspired introspection on the nature of music as a human endeavor, and what it would (or even could) mean to an alien species. If an ET even has ears, it’s still far from clear whether it would or could appreciate rhythm, tones, vocal inflection, verbal language or even art of any kind. As music scholars Nelson and Polansky put it, “By imagining an Other listening, we reflect back upon ourselves, and open our selves and cultures to new musics and understandings, other possibilities, different worlds.”

    The records also represent humanity’s deliberate effort to put artifacts among the stars. Unlike everything on Earth, which is subject to erosion and all but inevitable destruction (from the sun’s eventual demise, if nothing else), the Golden Records are essentially eternal, a permanent time capsule of humanity. And unlike the Voyager spacecraft themselves – which were designed to have finite lifespans and whose journey into interstellar space was incidental to their primary function of exploring the outer planets – the Golden Records’ only purpose is to serve as ambassadors of humanity to the stars.

    Placing artifacts in interstellar space thus makes the galaxy subject to the social studies, in addition to astronomy. The Golden Records mark our claim to interstellar space as part of our cultural landscape and heritage, and once the Voyager spacecraft themselves are not functional any longer, they will become proper achaeological objects. They are, in a sense, how we as a species have planted our flag of exploration in space. Anthropologist Michael Oman-Reagan muses, “Has NASA been to interstellar space because this spacecraft has? Have we, as a human species, [now] been to interstellar space?”

    I would argue we have, and we are a better species for it. Like the Pioneer plaques and the Arecibo Message before them, the Golden Records inspire us to broaden our minds about what it means to be human; what we value as humans; and about our place and role in the cosmos by having us imagine what we might, or might not, have in common with any alien species our Voyagers eventually encounter on their very long journeys.

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