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Voyager in Perspective

Joseph Green worked for 37 years in the American space program, retiring from NASA as Deputy Chief of the Education Office at Kennedy Space Center. His specialty was preparing NASA fact sheets, brochures and other semi-technical publications for the general public, explaining complex scientific and engineering concepts in layman’s language. Joe is the author of over 20 science papers for NASA and contractor executives, but I ran across him decades ago through his novel The Loafers of Refuge (Ballantine, 1965), a paperback that sits on my shelf not three feet from where I’m writing. Joe’s five science fiction novels, which include Star Probe (1976) and Conscience Interplanetary (1972), are complemented by about 80 shorter works, and he remains active writing for online magazines, with recent stories in the February and May 2013 issues of Perihelion Science Fiction. As Joe explains, 31 years at Kennedy Space Center puts a wonderful spin on recent events. Sometimes the future happens faster than we think.

by Joseph Green


Not long ago the morning paper carried a front page though below-the-fold story to the effect that space scientists, working from accumulated and analyzed data, have finally agreed that the Voyager I spacecraft entered interstellar space on August 25, 2012. Up until now the exact time has been a matter of dispute. The spacecraft is still operating, and expected to have enough power to keep sending back reports, from at least one sensor, until about 2025.

In 1977 I manned a console as a member of the Atlas/Centaur launch team. I also prepared the A/C technical documents, including the “NASA Fact Sheet(s)” distributed in advance of each launch. These were a compilation and distillation of the most important basic data on both spacecraft and launch vehicle. They were carefully written for the layman, explaining the mission in terms understandable to most high school juniors. I inaugurated the series, and they became very popular with non-technical Kennedy Space Center personnel, the general public, and in particular the news media (the last for obvious reasons — a lot of their work done for them).

Although I wasn’t a member of their teams, the Delta and Titan/Centaur managers tasked me with preparing Fact Sheets for their missions as well. The much larger and more powerful Titan/Centaur had been chosen as the launch vehicle for the Voyagers because of the weight of the (at the time) highly sophisticated robot explorer, and the unusually high velocity needed to reach Jupiter in 18 months.

After a close-up exploration of Jupiter and several of its moons, Voyager I went on to Saturn for another flyby, then headed into interstellar space. The last was basically frosting on the cake, as was the photo Voyager I took on February 14, 1990, looking back at the Solar System (showing Earth as a “pale blue dot”). The two most important mission objectives had been successfully accomplished. Few expected this hardy explorer to still be functioning and reporting back when its escape velocity of 17 kilometers per second (in relation to the Sun) took it into interstellar space. But it’s there, and with another decade (hopefully) of life expectancy.


Image: The Voyager missions with their direction of flight indicated. Credit: NASA/JPL.

The journeys of the Voyagers have been reported here on Centauri Dreams and widely discussed in other media. For me, they trigger reflection and thoughts on perspectives. Mine is that of a teenager reading science fiction in the 1940s, never dreaming that mankind would land on the Moon in my lifetime (2050, perhaps?). And sending a robot into interstellar space was in the far, far future, something my great-grandchildren might try. And yet I not only lived to see both, I actually played a small role in these two great scientific adventures. Those of you growing up at a time when you rather expected to see men walking on the Moon, or robots reporting back from interstellar space, may have an entirely different perspective.

Sometimes the glamor and excitement of manned space flight tends to overshadow the accomplishment of the Voyagers, Pioneers, and other doughty robotic explorers. But in many ways unmanned spacecraft have contributed more to our knowledge of the solar system, and galaxy/universe than the manned programs. We’ve now had robot explorers do close-up, highly instrumented flybys of all eight planets, and one is on its way to the disenfranchised Pluto/Charon system. These accomplishments, it seems from this perspective, are worthy of more respect than they have received from the world at large.


Comments on this entry are closed.

  • Christopher Phoenix September 30, 2013, 18:16

    I agree, the robot explorers don’t receive the respect they have earned through their exploratory achievements. The glamour of crewed space flight is undeniable… we humans relate best to human explorers, and dream of standing on these distant celestial worlds ourselves. But the hardy little robots have afforded us our best look at the rest of the solar system and the universe beyond, and will continue to do so.

    This trend will probably continue into interstellar space as well. The first interstellar explorers will most likely be hardy, advanced space probes designed to continue functioning for the decades to centuries required to reach the nearest exoplanets and report back.

    The first age of space exploration has been carried out by the hardy little probes… and the curiosity and hopes of our entire species have been carried by them out beyond the Sol system!!

  • Peter Chapin October 2, 2013, 7:15

    Humans are well adapted to life on Earth but require so much infrastructure to support life in space that I wonder if it will ever be economically feasible for humans to live in space long term. I suspect it will be our machines that will explore the stars as our proxies, and not us directly.

    In any case congratulations to the Voyager team for its stunning success, both in the solar system and now beyond it. We need more missions like Voyager!

  • Astronist October 2, 2013, 8:40

    Worth making it clear for lay readers that the Voyagers, Pioneers 10 and 11 and now New Horizons were already interstellar vehicles once they passed Jupiter, as after that point they were travelling too fast to remain bound to the Sun. Voyager 1 has now passed the heliopause, which marks interstellar space only in the sense of the Sun’s magnetic influence, and which is (according to your graphic above) different distances from the Sun in different directions. The Sun’s gravitational influence extends out to a light-year or so, and it will be a long time before Voyager 1 passes beyond that, or even beyond the aphelion distance of Sedna (937 AU), the outermost currently known worldlet. But there is no sharp or stable boundary in space where one can say that solar space ends and interstellar space begins.


  • Eniac October 3, 2013, 20:38

    If we ramp up sending probes on interstellar trajectories, in the long run we will end out with a steadily expanding cloud of explorers expanding at, maybe, 100-200 km/s. In time, probes will be made to communicate with each other as well as (or instead of) with Earth. This will, in very natural fashion, create the nucleus of the galactic internet we have talked about before. In this fashion, we will be on our way to exploring the entire galaxy, a task that could be completed in a “mere” few hundred million years or so.

    You see, our space program is not really stagnating, and we do not have hundreds of years to wait to become interstellar.

    We are already on our way ….

  • ljk October 16, 2013, 11:58

    Voyager 1: ‘Interstellar Media’ mobile

    11 October 2013 by Shannon Bohle, posted in Archives, Uncategorized

    [This blog post is a continuation of “Voyager 1 Reaches Interstellar Space” posted on Nature’s Soapbox Science.]

    Boldly Traveling Where No Archival Recording has Gone Before

    Transportation of books and other media for sharing and circulation with our friends and neighbors has been around for centuries — occurring first on foot, then hoof, then motorized wheel, and now, inertia.

    The fact is, “long before Amazon was bringing books to your doorstep, there was the Bookmobile! A travelling library often used to provide books to villages and city suburbs that had no library buildings, the bookmobile went from a simple horse-drawn cart in the 19th century to large customised vehicles that became part of American culture and reached their height of popularity in the mid-twentieth century.”

    When it came to education, the bookmobile helped cross many barriers prior to Voyager 1’s crossing into interstellar space. These barriers, however, were social. A sample collection of images of early [motorized] bookmobiles used in the US and abroad reveals how the bookmobile was critical to educational outreach. The images help capture how the library, and the bookmobile in particular, served as a tool used for inclusivity, crossing barriers of social class, race, gender, age, and geographic location. The bookmobile helped unite the planet — the wealthy and poor, black and white, young and old, inner city and remote mountains — by appealing to our common desire for learning and intellectual exploration and then reaching out to everyone.

    Full article here:


    To quote:

    In Cosmos (Random House, New York, 1980, 282), Sagan would later write, “Books permit us to voyage through time, to tap the wisdom of our ancestors. The library connects us with the insights and knowledge, painfully extracted from Nature, of the greatest minds that ever were, with the best teachers, drawn from the entire planet and from all of our history, to instruct us without tiring, and to inspire us to make our own contribution to the collective knowledge of the human species. Public libraries depend on voluntary contributions. I think the health of our civilization, the depth of our awareness about the underpinnings of our culture and our concern for the future can all be tested by how well we support our libraries.” Sagan’s own personal papers, comprised of 595,000 items, were donated to the Library of Congress in 2012.

  • ljk October 18, 2013, 14:35

    Interstellar 8-Track: How Voyager’s Vintage Tech Keeps Running

    BY ADAM MANN 09.25.139:30 AM

    NASA’s Voyager 1 spacecraft has gone interstellar.

    Launched in 1977, the probe is vintage space hardware. At more than 36 years old, or roughly a millennium in computer years, it’s an impressive feat to have the spacecraft drifting through the material between stars. Looking at the machine’s specs is a reminder of how far electronics have come in the intervening years.

    The computer room during Voyager’s testing days. NASA

    “Here on the ground, we keep up with the latest technology,” said engineer Suzanne Dodd, the Voyager project manager at JPL, with most of the science team using Mac power books these days. She recalled when she started working with the mission in 1984, they were using then-state-of-the-art desktop computers with 8-inch floppy drives.

    But Voyager 1 and 2 are from an even earlier era and, being 19 billion kilometers away, “you can’t take them into the shop and upgrade them,” said Dodd.

    The computers aboard the Voyager probes each have 69.63 kilobytes of memory, total. That’s about enough to store one average internet jpeg file. The probes’ scientific data is encoded on old-fashioned digital 8-track tape machines rather than whatever solid state drive your high-end laptop is currently using. Once it’s been transmitted to Earth, the spacecraft have to write over old data in order to have enough room for new observations.

    The Voyager machines are capable of executing about 81,000 instructions per second. The smart phone that is likely sitting in your pocket is probably about 7,500 times faster than that. They transmit their data back to Earth at 160 bits per second. A slow dial-up connection can deliver at least 20,000 bits per second.

    Full article here:


  • ljk October 19, 2013, 18:50

    3 October 2013, 3.22am BST

    Beyond the morning star: the real tale of Voyagers’ Aboriginal music

    Earlier this year, NASA spacecraft Voyager 1 left our solar system after a 35-year journey, carrying with it a golden record containing sounds, images and music from Earth.

    Its sister craft, Voyager 2, carries an identical record. The records were designed to encapsulate the aural heritage of Earth in 90 minutes – but some preliminary investigation, however, reveals that there a few inaccuracies in the official NASA documentation about the golden records.

    When senior Aboriginal men Djawa, Mudpo and Waliparu gathered one night in 1962 on Milingimbi mission in Arnhem Land for a recording session with Australian anthropologist Sandra Le Brun Holmes, they little dreamt that their music would be heading to the stars on the famous spacecraft.

    Full article here:


    To quote:

    Frozen in time or a living future?

    This is how Sagan summed up the purpose of the golden records in 1978, the year following their launch:

    Our concern with time and our sense of the Voyager message as a time capsule is expressed in many places on the record – greetings in Sumerian, Hittite and !Kung, photographs of Kalahari Bushmen, music from New Guinea and from the Australian Aborigines, and the inclusion of the composition “Flowing Streams”, whose original structure antedates Pythagoras and perhaps goes back to the time of Homer.

    Interestingly, the Indigenous groups mentioned here are among those most often singled out in early anthropology and popular conceptions as the most “primitive” on Earth. They are mentioned in the same breath with long-dead cultures known mainly from archaeology.

  • ljk October 19, 2013, 23:18

    In Search of Extraterrestrials

    Azerbaijani Music Selected for Voyager Spacecraft

    by Anne Kressler

    Azerbaijani music is on its way to the stars encased in a gold-coated, copper phonograph record attached to the sides of two NASA spacecrafts, Voyagers I and II, which were launched on August 20th and September 5th, 1977. For the past thirteen years, these two spacecrafts have been sending back photos from Jupiter, Saturn, Uranus, Neptune and beyond on their lonely voyages that will eventually, if all goes as scheduled, take them beyond the earth’s solar system.

    NASA scientists who organized this project were intrigued by the possibility that extraterrestrial life might exist. If it did and if it could be contacted, then they wanted to try to send a token from human life on earth of “our sounds, our science, our images, our music, our thoughts and our feelings.”

    Along with 90 minutes of some of the world’s best music, the record which is identical in both spacecrafts, includes three other major sections: greetings in 55 different languages, a sound essay, (Sounds of Earth), and a digitized photo essay of 118 photographs showing what man looks like and some of the things he has achieved.

    On the one hand, the Voyager’s record is like a 20th century time capsule which potentially could survive a billion years into the future. On the other, it’s something like a bottle cast into the ocean, hoping that someone, somewhere, will eventually find and read its message. Except that this time, the ocean is a galaxy so large it’s beyond imagination and the chances are extremely slim that any extraterrestrial, if there is such form of life, could, or ever would, find it.

    But the possibility of contacting intelligent extraterrestrial civilization always stirs our imagination so, perhaps, the value of such an experiment is much more beneficial to us human beings on earth than to extraterrestrials.

    As B. M. Oliver, Vice-President for Research and development at Hewlett-Packard Corporation said at the time, “There is only an infinitesimal chance that the plaque will ever be seen by a single extraterrestrial, but it will certainly be seen by billions of terrestrials. Its real function, therefore, is to appeal to and expand the human spirit, and to make contact with extraterrestrial intelligence a welcome expectation of mankind.” (Murmurs, 11).

    Full article here:


  • ljk October 27, 2013, 23:34

    Gibbons: Voyager still carries our hopes of finding that we’re not alone

    Journey of Voyager 1 through space has been marked by milestones in scientific exploration and learning

    By Chris Gibbons | October 26, 2013 | Updated: October 26, 2013 4:57pm

    On Sept. 5, 1977, humanity stood at the shoreline of the ancient cosmic ocean that had been beckoning for generations, and with a massive, rocket-propelled heave, we hurled a kind of message in a bottle out into the vast sea of space. That “bottle” was Voyager 1.

    Within its spindly metal framework was a gold-plated audio-visual disc filled with photos, music and messages from the people of Earth. Although its primary mission was to conduct a scientific reconnaissance of Jupiter and Saturn, scientists also knew there was a good chance that the probe would eventually leave our solar system someday and enter the great void of interstellar space.

    Consequently, a team of scientists and engineers, led by Carl Sagan, viewed Voyager as a unique opportunity for humanity to send a greeting card into space – a cosmic message in a bottle.

    And, like children on a beach, we have patiently watched our bottle slowly drift farther and farther from shore. Last month, we learned that it finally has dipped below the horizon, and we can do nothing more now than simply hope that, someday, our bottle may be found.

    Full article here:


    To quote:

    What the retrievers of Voyager 1 could never comprehend is that one of humanity’s primary motivations in sending this message in a bottle was something that couldn’t be placed on a gold-plated disc or etched into the metal chassis of our robot emissary. It is a certain longing that has been troubling us for decades, and it chills our souls whenever we contemplate the size of the universe and the incredible number of stars and planets contained within it.

    For each time we have shouted out into the deep, infinite expanse of space and listened for a reply, the only response we’ve received has been a disturbing silence. The bottle couldn’t possibly convey that we have always felt so very alone and desperately hoped that we were not.

  • ljk October 28, 2013, 21:45

    Voyager’s view

    Spacecraft’s journey to interstellar space helps put the solar system in perspective

    BY ANDREW GRANT 4:47 PM, OCTOBER 4, 2013

    Magazine issue: October 19, 2013

    It’s finally official: Voyager 1 has become the first human-made object to enter interstellar space, mission scientists report September 12 in Science. On August 25, 2012, the scientists say, Voyager 1 exited a giant invisible bubble called the heliosphere that is inflated by a torrent of subatomic particles spewing from the sun.

    Now the probe is surrounded almost exclusively by particles produced by other stars. But whether it’s correct to say that the probe has left the solar system depends on how you define the solar system.

    “From my perspective, Voyager is nowhere near the edge of the solar system,” says planetary scientist Hal Levison of the Southwest Research Institute in Boulder, Colo. The sun continues to exert gravitational dominance out to hundreds of times the distance of Voyager 1 from the sun, where trillions of icy pebbles, boulders and comets orbit.

    In the last 36 years, Voyager has traveled an impressive 25.4 billion kilometers, but it still has a long way to go to unambiguously depart the solar system.

    Full article here:


  • ljk October 28, 2013, 23:46

    How Voyager Became A Grand Tour

    By Amy Shira Teitel Posted 10.18.2013 at 11:05 am

    A few weeks ago, NASA announced that Voyager 1 has become history’s first interstellar spacecraft. More than 11 billion miles from the Earth and 35 years into its mission, sometime in early August 2012 the spacecraft left the heliosphere, that invisible bubble where the solar wind’s influence dominates.

    Now in the wholly unknown environment of interstellar space, Voyager 1 promises to return a wealth of previously unattainable data for scientists and an equivalent trove of inspirational discoveries and perspectives for non-scientists. Even if our emissary is crippled and slowly decaying, humanity has become an interstellar species.

    Voyager’s news was slightly tainted by the number of false alarms raised in the last year; it seems that every few months a story surfaced saying Voyager had left the Solar System only to be corrected and retracted. Understandably. It’s not easy to pinpoint the moment a spacecraft enters interstellar space, particularly with decades old systems failing. The science team had to creatively repurpose what working instruments Voyager 1 has left to confirm its interstellar status.

    It’s incredible to think that two spacecraft built with Apollo-era technology and launched more than three decades ago are still working. But perhaps even more incredible is that the Voyager missions happened at all.

    Full article here:


  • ljk November 26, 2013, 10:31

    Cosmos with Cosmos Episode 6: Travellers’ Tales

    Voyager is the ultimate expression of our desire to explore

    Posted by Casey Dreier

    2013/11/25 03:56 CST


    To quote:

    Svante Pääbo is the Director of the Max Planck Institute for Evolutionary Anthropology in Germany, where he specializes in sequencing the DNA of ancient creatures. He often asks himself the question of why humans were driven to explore and neanderthals were not.

    There is a compelling argument that our drive to explore – Pääbo calls it our “madness” – is related a series of genetic mutations that are unique to humans. Variants of the gene DRD4, for example, have been linked to restlessness and risk taking, and Pääbo believes it represents the mutations that made us the type of species that looks across an endless ocean and thinks “let’s see what’s out there.”

    I don’t think anyone seriously believes that our drive to explore is a work of a single gene, but I do see how a set of mutations of various genes could increase this tendency and thereby increase their likelihood for reproduction. By reaching out into new places, we exploit untapped biological niches for ourselves. We face animals that aren’t evolved to hunt us. The flexible software of our brains could more quickly adapt to new surroundings, and in doing so the new surroundings would themselves select for our own adaptations that make us flexible. The drive for exploration and expansion in this sense can be considered a phenotype – the physical expression of a gene or set of genes in an organism.

    But phenotypes don’t just represent physical characteristics. Richard Dawkins expanded on the concept with his theory of the extended phenotype, which is any characteristic or expression in the world that helps in the survival of those genes, regardless of whether they are in the same body of the genes themselves.

    Thought of in this way, the Voyagers are the ultimate extended phenotype of our species. A few mutated genes in the bodies of our ancient ancestors hundreds of thousands of years ago have found their expression in the hardened metal and golden plates of these spacecraft. Our expansionist, exploratory desires may be our most important evolutionary trait we have, maybe driving us off this planet and onto another, saving us from the vulnerable position our species finds itself in.

    The neanderthals lacked this desire and they suffered dearly. Their genes didn’t carry them out beyond much of anything. Our genes give us a predilection to explore, but we must consciously choose to do so. We’ve seen both in culture and in biology that uninquisitive, cautious groups die while the bold thrive.

    Which society would you rather live, one that looks out or one that looks in? As NASA budgets decrease and we find ourselves explaining away exploration as too costly, Sagan reminds us here that we owe it to ourselves to embrace the gift our genes bestowed upon us.

  • ljk January 25, 2014, 16:33

    GEORGE DVORSKY on IO9 THIS IS AWESOME Yesterday 2:20pm

    This mind-bending music was created using Voyager spacecraft data

    An Italian scientist has taken 37 years worth of data from both Voyager space probes and turned it into music. The result is surprisingly good.

    The composer, Domenico Vicinanza, is a project manager at Géant — Europe’s high-speed data network that powers Cern and the Large Hadron Collider. He used 320,000 individual measurements of cosmic particle data taken at one-hour intervals using the spacecrafts’ cosmic ray detector.

    Full article here:


  • ljk February 21, 2014, 0:23

    FEBRUARY 19, 2014



    Last September, the Times reported that Voyager 1, the hardy spacecraft launched in 1977, had exited the solar system and entered the interstellar void. Whenever stories about Voyager 1 and Voyager 2 appear in the papers, I read every word, transfixed: I was nine years old when the vessels began their journeys outward, and avidly followed news of their early progress. When, in 1981, I changed schools, a favorite teacher gave me a copy of Carl Sagan’s book “Murmurs of Earth,” which describes the Golden Record affixed to both Voyagers—a disk containing greetings, natural sounds, pictures, and music, intended to document human civilization for the possible benefit of extraterrestrial beings. To hear that Voyager 1 is now nineteen billion kilometres from Earth is a precise indicator of the aging process. At the same time, the craft’s longevity—it is expected to continue sending data until 2025—is vaguely encouraging. May we all transmit so reliably.

    Recently, the composer Raphael Mostel told me that one of his colleagues, the composer, musician, and software engineer Laurie Spiegel, has intimate knowledge of the Golden Record and of the curious legal issues it raised. For a section of the disk entitled “Sounds of Earth,” Sagan’s sonic team had chosen Spiegel’s piece “Harmonices Mundi.” Spiegel was given a contract to sign, a copy of which she kept in her files. When I asked about it, she kindly sent me a scan of the document, which will be of interest to specialists in the obscure and complex field of Space Copyright Law, and possibly a few connoisseurs of avant-garde legal language.

    Full article here: