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The Rhetoric of Interstellar Flight

Isn’t it fascinating how the Voyager spacecraft keep sparking the public imagination? When Voyager 2 flew past Neptune in 1989, the encounter was almost elegaic. It was as if we were saying goodbye to the doughty mission that had done so much to acquaint us with the outer Solar System, and although there was talk of continuing observations, the public perception was that Voyager was now a part of history. Which it is, of course, but the two spacecraft keep bobbing up in the news, reminding us incessantly about the dimensions of the Solar System, its composition, its relationship to the challenging depths of interstellar space the Voyagers now enter.

In the public eye, Voyager has acquired a certain patina of myth, a fact once noted by NASA historian Roger Launius and followed up by author Stephen Pyne in his book Voyager: Seeking Newer Worlds in the Third Great Age of Discovery:

…the Voyager mission tapped into a heritage of exploration — that was its cultural power. But there was always to the Grand Tour a quality that went beyond normal expeditioning, a sense of the providential or, for the more literary, perhaps of the mythical. The aura would have embarrassed hardheaded engineers intent on ensuring that solders would not shake loose during launch and electronics could survive immersion in Jovian radiation. Yet it was there, a tradition that predates exploration and in fact a heritage that Western exploration itself taps into.

Part of that mythos is the fact that the Voyagers persist, year after year, decade after decade, with perhaps another ten years ahead before they go silent. People who were born the year of the Voyager launches are now in their 34th year, and as of this morning (local time) at 1307 UTC, Voyager 1 has flown 19,228,196,899 kilometers and counting. And just when we’ve begun to absorb the distances and ponder the continuing data return, Voyager does something new to catch our eye, in this case a roll maneuver on March 7 needed to perform scientific observations.

A Star to Guide Us

Something new? Ponder this: Except for a test last month, the last time Voyager performed a roll like the 70-degree counterclockwise rotation (as seen from Earth) it performed this week, it was to snap a rather famous portrait, an image of the planets around the Sun including the ‘pale blue dot’ of Earth. That was back in February of 1990, fully 21 years ago, although to me it seems like yesterday. This time the roll was for a different purpose. Rather than looking back, the vehicle was looking forward, orienting its Low Energy Charged Particle instrument to study the stream of charged particles from the Sun as they near the edge of the Solar System.

The new roll, held in position by spinning gyroscopes for two hours and 33 minutes, tells us that the old spacecraft still has a few moves left. Suzanne Dodd is a Voyager project manager at JPL:

“Even though Voyager 1 has been traveling through the solar system for 33 years, it is still a limber enough gymnast to do acrobatics we haven’t asked it to do in 21 years. It executed the maneuver without a hitch, and we look forward to doing it a few more times to allow the scientists to gather the data they need.”

You may recall that back in June of last year, the same Low Energy Charged Particle instrument began to show that the net outward flow of the solar wind was zero, a reading that has continued ever since. The question now under scrutiny is just how the wind — an outflow of ions from the Sun — turns as it reaches the outer edge of the heliosphere in the area known as the heliosheath. Outside the ‘bubble’ of the heliosphere is the interstellar wind, and the complex interactions between our own star and the interstellar wind are now Voyager’s raison d’etre.

It gives me a kick to realize that when the recent test roll was accomplished on February 2, the spacecraft quickly re-oriented itself by locking onto a guide star with some resonance here, Alpha Centauri. And now that the Low Energy Charged Particle instrument team has acquired what it needs, mission planners are looking to do another series of rolls in coming days as the study of the heliosheath continues. I admit to liking the idea of Alpha Centauri as a guide star for all it conjures up about bright stars in southern skies and ancient voyaging deep into wine-dark seas.

Making the Interstellar Case

Does it also point to future voyaging as we venture outside the range of our own Solar System? Let’s hope so. It’s interesting to see that Stephen Hawking and Buzz Aldrin have joined forces in what they’re calling a Unified Space Vision to “…continue the expansion of the human presence in space and ensure the perpetuation of the species.” Voyager, of course, is a robotic presence, but as we push the boundaries of artificial intelligence with ever more sophisticated probes, we’ll be finding out how the human angle meshes with robotic investigations. I suspect the distinction between living and robotic is going to be less significant as we extend our reach outward.

Human or robot, deep space demands what I might call a rhetoric of interstellar flight, and maybe that’s where Hawking and Aldrin come in, along with The Planetary Society, and Project Icarus, the British Interplanetary Society and Tau Zero. Because Voyager continues to capture the imagination, and that tells me that the innate quality that makes people explore is not a trait we have lost in our time. One of the three ancient arts of discourse, rhetoric is all about how you make the case for something. It’s a way of framing a debate, using language persuasively, and when used right it’s the counterpoise to sophistry. A skilled rhetorician can convince you of the merits of a case, but he or she will do so using logic as a way of getting at underlying truth.

We need to make the interstellar case. It’s the one triggered by every new report from spacecraft that really are going where no one has gone before, and it relies on our understanding that even as we work to solve problems here at home, we must not stop dreaming and planning for a future that pushes our limits hard. Recently we’ve discussed the effects of tightened budgets on NASA missions to the outer system, but the larger picture — the one we need to bring to the public — is that the time-frame for our explorations is less essential than the persistent effort to make them happen. We’ll build a future in space one dogged step at a time, and when asked how long humanity will struggle before reaching the stars, we’ll respond, “As long as it takes.”


Comments on this entry are closed.

  • Eniac March 10, 2011, 10:40

    I wonder if Voyager could be made to do an “extremely long baseline” observation that could obtain data that would not otherwise be possible. It could be recording radio waves from an object of interest, while an Earth based telescope does the same thing. Once the data is downlinked, it could be processed for interferometric information.

  • Alex Tolley March 10, 2011, 11:08

    I think it will be very hard to make a case for human interstellar travel. With our present knowledge of physics (and biology), if you want to make the case for long term human survival, i.e. 1 million years without extinction plus a high tech society, it might be a lot cheaper to defend earth against possible extinction events, plus start solar system colonization, whether on planetary and satellite surfaces, or in free flying habitats.

    The costs of sending meat in cans on interstellar journeys is prohibitive for possibly hundreds of years. Even cathedral builders had shorter time frames. Sending machine intelligences is far more likely, especially if they are very small small.

    But if we are already having problems with METI, how much worse push back will we have if we send physical representatives out to the stars?

    The rhetoric against interstellar travel will be a lot easier than that for it.

    Some breakthrough in physics might change that equation if the capability and costs suddenly came within the reach of a country, organization or individual. I wouldn’t bet on it, but the universe keeps surprising us.

  • Greg March 10, 2011, 12:03

    “It’s the one triggered by every new report from spacecraft that really are going where no one has gone before, and it relies on our understanding that even as we work to solve problems here at home, we must not stop dreaming and planning for a future that pushes our limits hard.”

    Nicely said Paul, nicely said indeed!

  • Paul Gilster March 10, 2011, 14:13

    Thank you, sir! Much appreciated.

  • The Cosmist March 10, 2011, 16:39

    Nice essay Paul. Making the interstellar case now is probably like someone in the 17th century making the case for a lunar flight. While they may have understood celestial mechanics and could calculate that it was possible, their engineering capabilities were so far from making it feasible that people would consider them crazy.

    Interstellar flight is a problem we should definitely be thinking about and working on, but right now I’d like to see the *interplanetary* case being made more forcefully. The issue is one of incrementally scaling up; jumping from our current distance and energy scales to those required for interstellar flight will look at lot more feasible after we’ve sent probes to the Kuiper belt, developed a space industry, mastered fusion power, space-based solar power, mined the asteroids, colonized Mars, etc. So my question is this: if someone wants to make a contribution to practical space exploration in their lifetime, what path should they pursue?

  • ljk March 10, 2011, 16:56

    As I have said with NASA, interstellar travel should be treated thusly:

    Robots for exploration and discovery.

    Humans for colonization.

    Of course the two will work together to varying degrees, but the above is the overall stance we should take with our space agency and our interstellar plans. I am also thinking that humans may be better off living in space rather than on another planet, as there probably will not be an exact duplicate of Earth where a human could just step out of the ship without an environmental suit.

    I also think that by the time we are ready to send our first vessels to the nearest stars, machine intelligence and ship technology will be highly sophisticated and much more capable than any human. If any starships do have actual human passengers (assuming our species has not radically changed itself in the next few centuries), they will be for one-way trips to start life on new worlds, or perhaps to roam the Milky Way for generations, stopping at worlds for exploration and resupply only.

  • Ronald March 10, 2011, 18:57

    “We’ll build a future in space one dogged step at a time, and when asked how long humanity will struggle before reaching the stars, we’ll respond, “As long as it takes.””

    Those words move me, very well said, Paul, keep up the good work and the advocacy!

  • Ronald March 10, 2011, 19:01

    Ref. Alex Tolley and ljk: if we ever make it to the stars as human beings, I think it will be either some kinde of ‘break-through physics’ or a combination of ‘conventional’ (nuclear) physics and some kind of suspended animation and/or drastic life extension.

    See also recent articel on Next Big Future;

  • Marc G Millis March 10, 2011, 19:15

    Regarding near-term ambitions versus going for the huge gains…

    If you get a chance, read Foster’s book, “Innovation, the Attacker’s Advantage.” While there is undeniable value in improving established efforts, history has repeatedly shown that such refinements do not lead to (and can often impede) the inventions of the high-performance devices that obsolesce those incumbents. As just one example, transistors were not invented by improving vacuum tubes.

    While the bulk of the aerospace community is going for those nearer goals, Tau Zero provides a venue to pursue the disruptive advancements that can change everything. There is no guarantee that this tactic will work. It is a risk. But, may I dare quote Captain Kirk, “Risk is our business.” By providing the niche where the more adventurous minds can collaborate, we stand a better chance of discovering those game-changing advancements.

    But that is not all. As much as the lunar flight contemplations would look crazy to the average 17th century dude, those average dudes are not what we are seeking. We are trying to find the most ‘pioneering’ folks, and help them, work with them. To the average person, daunting goals seem intractable. To the pioneer, they have a knack of finding the next steps to chip away toward those huge gains. “A journey of a hundred light-years begins with a single step” (Confucius extended 12 orders of magnitude). It is my hope, that by providing a forum to share news of this kind of progress and collaborations, that we will discover things sooner than just the approach of extrapolating the known. Those other, nearer term efforts should continue too, but not to the exclusion of deeper imagination and reasoning.

    And lastly, look at the state of affairs of current space activities. Their ambitions are outclassed by their budgets. That means their business as usual will be slow. It is my hope that our little niche beyond, to seek starflight, will break past those efforts. And remember, when breakthroughs happen, the skeptics are surprised while the pioneers were simply doing what came naturally.

    So, do you want better vacuum tubes, or are you willing to delve into uncharted possibilities?

    Ad astra incrementis – to the stars in ever-increasing steps.

  • Paul Gilster March 10, 2011, 21:17

    Ronald, thanks for your kind comments, and thanks especially for your many contributions to Centauri Dreams over the years.

  • bigdan201 March 10, 2011, 22:15

    The blurring between human and machine has been considered in Ghost in the Shell and in many other sci-fi works. It is likely that we will augment ourselves further as we colonize space, but to what extent is up to speculation.

    Personally, I feel that the solar system and other stars are in two different categories. Sending a robot probe to a nearby star (alpha centauri etc) is the most feasible option in the near term. Other than that, we will build up a solar system wide infrastructure and economy before we journey to the stars.

    However, if there is a viable exoplanet(s) in a system within 20 light years or so, that will change things quite a bit. A viable exoplanet at alpha centauri is most likely wishful thinking, but that would be even more significant. The observation and knowledge of such a destination would fuel the drive for interstellar voyaging and colonization.

    In any case, it is important to keep science and the possibilities of space relevant. Too many people don’t even consider these topics, so achievements of the Voyagers and the like will help to fuel interest. Science fiction has also played an important role in my opinion.

  • Procyan March 11, 2011, 2:40

    I wish you would write a book about AC for the layman. I’ve had good reads about Jupiter, Mars and other solar system objects but either I’m missing it or that up-to-date update on AC just doesn’t exist.

    In particular there might be chapters on planets. especially timely as new information will be coming to the fore on AC in this regard

    Update on solar system structure(s) and evolution incorporating new info from astronomy. Does AC have a Kuiper belt or Oort cloud…do we :)

    I know that Proxima is a flare star, but don’t understand why little stars trend in this way…whats that story??

    well anyway, the more I think about it the more there is to wonder about. Many answers waiting but you could write such a grand book and it would not hurt the “cause” of starflight for people to start thinking about AC as more than a pointer star.

  • bill March 11, 2011, 4:13

    I know your occupation is a writer, but I have to say Paul you’re an
    elegant wordsmith !!

  • Ronald March 11, 2011, 5:14

    Marc Millis: very nice and inspiring comment!

    And your adapted saying “A journey of a hundred light-years begins with a single step” will, of course, become a household expression in coming centuries ;-)

  • Paul Titze March 11, 2011, 6:42

    The Cosmist wrote:

    “So my question is this: if someone wants to make a contribution to practical space exploration in their lifetime, what path should they pursue?:

    Learn as much as you can about Physics and specialise in Propulsion Physics. If you want to make a major contribution to practical space exploration, a good start is finding a way to get large amounts of hardware into orbit without using chemical rockets. General Relativity and the Standard Model appear to model Nature very well however explore the loose ends and see where they lead.

    Cheers, Paul.

  • Paul Gilster March 11, 2011, 8:32

    Thanks to both bill and Procyan for the fine comments. The word ‘wordsmith’ particularly pleases me ;-) As to a book on Alpha Centauri, Procyan is right that there are all kinds of interesting things it could contain, and much more we are about to learn with three ongoing radial velocity examinations of the stars. I can’t go into details yet, but don’t be surprised if a book like this emerges…

  • Ronald March 11, 2011, 11:29

    Of course a book about AC for a broader interested public (the ‘motivated amateur’) will have to be written, and of course Paul would be someone to do that or at least contribute to it, but I think we better still wait a little while until data are released from the three (?) ongoing research programs on AC planets. This would undoubtedly make a big difference with regard to the book’s meaning and content.

  • Greg March 11, 2011, 11:55

    Marc, I’ve been fighting that very battle for awhile. Companies tend to put R&D in small risk, short term, small pay-offs as compared to long term, high risk, high pay-offs. It’s even been shown that a company can make more money the riskier the venture. The only issue, and I think it’s the key to everything, is the chance of litigation. If something goes wrong people sue. Litigation can easily bankrupt a company. So thats why we have a new “Iphone” each year but no flying cars, imagine what would happen to a company if one fell out of the sky killing tens of people?
    What desperately need is laws preventing litigation in these cases.
    This only leads us to being risk adverse.

  • The Cosmist March 11, 2011, 18:41

    Paul, thank you for your advice. I’m totally obsessed with physics actually — does anyone have any advice for getting into a physics PhD program with a spotty resume at a slightly advanced age? My math & physics skills are not the problem, it’s the bureaucracy of modern academia that defeats me!

    Didn’t Freeman Dyson and the other Project Orion people figure out a way to get large amounts of hardware into orbit without chemical rockets 50 years ago? Didn’t they shelve the idea because Dyson calculated that every launch would on average kill several human beings?

    It seems to me that the larger problem is risk aversion; people in the modern West want the whole universe so long as it costs nothing and offends no one. This kind of timidity isn’t going to cut it for manned space exploration! I don’t know what the solution is other than to keep thinking boldly and hope things change; maybe it will be a non-Western civilization like China that has to carry the torch of humanity into space. At this point, I don’t really care who plants the flags!

  • Dwight Williams March 11, 2011, 22:22

    Whoever is working on a “briefing book” on Alpha Cen for laypeople such as myself, I’ll be looking forward to seeing it on the stands as soon as peer review permits.

  • bigdan201 March 12, 2011, 5:40

    Getting to orbit economically would be a very important advance. Concepts such as the launch loop or mass driver look promising, and there are other ideas too. Once that hurdle has been overcome, that will open up space to many more ventures – not only for science, but for commerce and industry too.

    To tie this into risk aversion, the fact that it costs so much to get to orbit presents a great risk – you have to make a big investment in a chemical launch and hope all goes well. With economic and reliable methods of getting to space, many more people will be interested in taking action.

    While I feel optimistic about mass drivers and launch loops, the biggest hurdle I see is getting them built. You have to make a big investment at first for a great long term payoff. The challenge will be convincing the powers that be that such a course is worthwhile and significant.

  • Paul Gilster March 12, 2011, 8:52

    Dwight Williams writes:

    Whoever is working on a “briefing book” on Alpha Cen for laypeople such as myself, I’ll be looking forward to seeing it on the stands as soon as peer review permits.

    Thanks, Dwight. This is an ongoing project and I’ll keep readers here posted on availability, etc. But it will be a while yet — Ronald was right (above) when he mentioned the ongoing searches for Centauri planets. We should have results in the near future, but that might mean a year or two out.

  • Debasish Ghosh March 18, 2011, 13:33

    Please ask experts with established name & contribution in their respected field to comment & give their view.Let them take some time to prepare such short to medium length comment & also provide their important references ,quotes .We would welcome criticism from well known critiques in their field of activity, otherwise why should I take interest in going through dozens of comments from anonymous people.