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Interstellar Flight: Risks and Assumptions

The interstellar mission that Dana Andrews describes in his recent paper — discussed here over the past two posts — intrigues me because I’m often asked what the first possible interstellar mission might be. Sure, we can launch a flyby Voyager-class probe to Alpha Centauri if we’re willing to tolerate seventy-five thousand years in cruise, but what would we accept by way of acceptable cruise times? The lifetime of a human being? Multiple generations? And if we had to launch as soon as possible, what would the mission parameters be?

The mission that Andrews conceives grows out of questions like these. I can say upfront that this isn’t a mission I would want to fly on. For one thing, it’s a generation ship, so entire lives will be spent in cramped quarters, and the prospect of being overtaken by a later, faster ship is always there. But that’s not the point. 18th Century voyagers with a yen for the unknown could have waited for the age of steamships, but how could they have anticipated it? In any case, waiting would have cost them the journey that was in front of them. I think there will always be pioneers in search of experience unique to them, the first to step onboard as long as a viable mission presents itself.

Yesterday we looked at various propulsion strategies for Andrews’ starship, including a personal favorite, the Sailbeam design of Jordin Kare, which uses tiny micro-sails driven by laser as a stream of beamed energy that can be ionized when it arrives at the ship, providing thrust to a magsail. Dana Andrews knows a lot about magsails — working with Robert Zubrin in 1988, he showed that Robert Bussard’s interstellar ramjets would produce more drag than thrust, and the idea of turning a magnetic scoop into a magnetic sail began to grow. We’re seeing that it can be used both for acceleration and deceleration upon arrival.

Andrews_magsail

Image: Interstellar generation ship configured for braking. Credit: Dana Andrews.

Several decades before the Andrews/Zubrin paper, Robert Forward had been taking note of laser developments at Hughes Research Laboratories in Malibu, CA. He already knew about solar sails, which had appeared in the work of Konstantin Tsiolkovsky and Fridrikh Tsander in the 1920s and which had been the subject of a technical paper by Richard Garwin in 1958. As a science fiction writer, Forward was surely aware as well of Carl Wiley’s “Clipper Ships of Space” article, which appeared under the byline Russell Saunders in Astounding Science Fiction. Why not, Forward mused, boost a solar sail with a laser?

I can see why Andrews included Forward’s laser lightsail ideas in the current paper, but the magsail seems like a far more likely candidate for the near-term mission that he describes. Even working with a minimal Forward configuration, we still have to solve problems of deployment and infrastructure that are huge, including, in Andrews’ calculations, a beam aperture fully 20 kilometers in diameter. He goes on to describe a lightsail mission with acceleration of 0.05 gees that reaches 2 percent of c in 155 days at a distance of 267 AU. “The minimum cost system is to invest in really good stationary optics,” he adds, “thereby allowing less power and smaller sails, but then beam jitter begins to dominate.”

Summing up the various propulsion methods discussed, Andrews comments:

We quickly examined four different near-term interstellar propulsion concepts. Each has its issues… The laser-powered ion thruster needs aggressive weights for the design to close, but has no obvious showstoppers. The Neutral Particle Beam concept appears workable at planetary distances, but requires very high acceleration and power levels to maintain divergence angles of one microradian or more. Projecting a beam of neutralized particles presents the problem of re-ionizing a dispersed cloud of particles, which is a definite showstopper. The Sailbeam propulsion has potential, but needs tests of the acceleration capability and is still power hungry (~4000 TW of electrical power for the example presented here). Even at 4000 TW it needs pointing accuracy better than a nanoradian to finish the acceleration. The laser-lightsail actually came off as relatively low risk at 800 TW of electrical power, but that is very dependent on the availability of a 20 km diameter diffraction-limited steering optic, and a one-gram/m2 lightsail (both risk factor 4+).

Andrews_power

Image: Total energy usage comparison. Credit: Dana Andrews.

What makes predictions about spaceflight so tricky is that we can’t anticipate the emergence of disruptive technologies. The risk factors that Andrews develops as he looks at the progress of interstellar flight are, by his admission, estimates and ‘guesstimates,’ which is about the best we can do, and he characterizes near-term technologies as less than risk factor 4.

Andrews_risk

Image: Relative risk between candidate interstellar technologies.

We can all find things we might take exception to here and there in this list. You can see, for example, that Andrews characterizes a breakeven fusion reactor at risk factor 4, with a 40 year development time. Fusion has wreaked havoc with our predictions since the 1950s, and I think it’s optimistic to hope for working fusion power-plants even within this timeframe, though I know fusion-minded people who think we’re much closer. Fusion for starship propulsion he ranks at a risk factor of 7, needing 100 years to develop. Notice, too, that for the purposes of this mission, freezing or suspended animation are ruled out as being at risk factor 9, which would place their development 400 years out. A disruptive advance could negate this.

I find it useful to lay out our assumptions in such direct form. The biggest question I have regards fully closed-cycle biological ECLSS (Environmental Control and Life Support Systems). At a risk factor of 2.5 and 25 years of development, we could deploy these technologies on a generation ship, but will they be tested and ready by late in this century, when the starship would presumably be launched? My own guesstimate would lean toward a higher risk factor and 50 years for development, a tight but perhaps possible fit.

Other things the ship will need: Protection against galactic cosmic radiation (GCR), which Andrews proposes may be resolved by using magnetic fields to deflect charged particles away from the crew areas. He gives the topic a fuller discussion in a 2004 paper (see citation below). Dust in the interstellar medium poses a challenge because at 2 percent of c, impacting particles become plasma and can cause erosion to the spacecraft. Andrews notes this will need to be addressed in any starship design but doesn’t elaborate.

The conclusions [Andrews adds] are that near-term interstellar colonization flights are not completely science fiction, but there has to be a powerful requirement to generate the funding necessary to work many of the problems identified. The alternative is to wait a hundred years or so for low specific power fusion, or much longer for warp drive. We’ll see.

The paper is Andrews, “Defining a Near-Term Interstellar Colony Ship,” presented at the IAC’s Toronto meeting and now being submitted to Acta Astronautica. The 2004 paper is Andrews, “Things To Do While Coasting Through Interstellar Space,” AIAA-2004-3706, 40th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, Fort Lauderdale, Florida, July 11-14, 2004.

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Comments on this entry are closed.

  • Michael October 8, 2014, 14:11

    I am not sure what the magnetic field density is inside the loop but would it not be better to have a tightly would coil which have the same magnetic moment but less frontal area to oncoming hazards. As for the technology risk factor list I see there is no fission implosion technology which is much easier to start than fusion, although it is less efficient fuel wise the technology is readily available with a risk factor of less than one as we have it now.

  • Alex Tolley October 8, 2014, 14:45

    18th Century voyagers with a yen for the unknown could have waited for the age of steamships, but how could they have anticipated it? In any case, waiting would have cost them the journey that was in front of them.

    There was never going to be the case that waiting for steamships would allow the steamship to reach the voyage destination first. Therefore no need to wait for better ship technology. A 200+ year trip to alpha Centauri at 0.02c might easily be overtaken by a 0.03c star ship leaving just 25 years later boosted by simply using a more powerful beam. While this really matters for the crew of the star ships, this isn’t as important for robotic probes. Launch now at 0.02c, and if you can justify a more modern, faster 0.03c probe, then launch that too and get better data faster. If not, the first probe can still do its job. As we’ve discussed before, the smaller we can make the probe, the cheaper the flight and the more likely and earlier it will be launched. I could easily see a wealthy, connected individual negotiate for asteroid deflection laser time to launch a swarm of sponsored, micro-probes that fly at 0.5c, returning video of an exotic world for paid entertainment from the surviving units a few decades in the future. “Farthest Coke in History” types of ads would bring in revenue during the flight ensuring early payback. (Heinlein had the right idea in “The Man Who Sold the Moon”).

  • Paul Gilster October 8, 2014, 16:36

    Alex Tolley writes:

    “Farthest Coke in History” types of ads would bring in revenue during the flight ensuring early payback.

    Love it! And, of course, the subsequent Heinlein reference.

    For readers interested in the issue of being caught by a faster technology, this 2006 piece digs into it a bit, with external references:

    https://www.centauri-dreams.org/?p=915

  • william October 8, 2014, 17:22

    Regards to the very interesting articles that have appeared here on this website in the last few days. I’d just like to add this concerning the aspect of motivation for possible interstellar flight.

    I have to agree with one of the earlier contributors viewpoints that the driving force of politics and money be probably insufficient to permit a long-term commitment to such program.

    May I humbly suggest that a alternative exist that would possibly fulfill the idea that we should disperse somewhat to counteract possible global difficulties and at the same time provide an impetus for ultimately doing interstellar exploration. And it is this: aside from Venus and some of the large gaseous outer planets almost all other bodies are more or less able to be used as colony basis. Thus, we have almost a unlimited number of objects within our solar system that can be occupied and called home. Such outpost could in time serve as a springboard for any one of them began an interstellar mission of their own. What do you all think?

  • norman wells October 8, 2014, 18:45

    I think that we should be concentrating on the possibility of an FTL communication technology . To me it seems pointless to consider any manned system for Deep Space Travel that cannot achieve two way transit times in fractions of a human life time And that applies most urgently to information transmission times which require to be reduced even for expeditions within our Solar system .
    We may not have the slightest idea of how it can be achieved today…….. but tomorrow who knows ?That it is in the nature of scientific discovery and although we have seen no evidence of its operational use to date any ware in the Universe , that may simply be because we do not know what form it takes.

  • Edg Duveyoung October 8, 2014, 22:10

    Any second now, we’ll be able to “read” the atmospheres of thousands of planets. If there’s “tech,” there’s good odds there’ll be a tell. And if so, then SETI can try for a closer look at what’s coming out of such planets. Who knows what I Love Lucy programs we’ll trip over, eh? In the above chart, I don’t see our system “going dark,” and, if so, probably other planets have “broadcasting windows” that are, say, a few thousand years wide. Chances are long though for us finding another civilization “at about our level of technology.”

    I’m 70 years old. My best hope is a telescope finding fossil data showing there “once was something industrial going on.” If so, that would be enough to smile about — to know there are others…..ahhhh…….such closure for so many issues.

  • Antonio October 9, 2014, 8:08

    “Fusion has wreaked havoc with our predictions since the 1950s”

    Nope. Not “since” but “in”. After the first years, it was clear to fusion researchers than it will take more time and, indeed, that fusion research progress follows an exponential law: https://www.euronuclear.org/e-news/e-news-15/listening.htm Triple product doubles each 1.8 years.

  • Brett Bellmore October 9, 2014, 10:22

    I have to agree with Alex: The original colonists/explorers knew fairly well that nobody was going to leave later and beat them to their destinations, because the technology of travel wasn’t advancing by leaps and bounds, and the trip duration was short compared to the rate of technology advance. Nobody was going to invent the Concorde while you were crossing the Atlantic on a sailboat.

    You’d have to be mad to set off on an interstellar trip at a tiny fraction of C, knowing that hundreds of years of technology advance would take place back home before you arrived, and that it was quite plausible that later departures would pass you up. I see only two scenarios where an early departure makes any sense:

    1. Lifeboat, where the entire solar system is due to become uninhabitable for some reason within a century or so, and you’re just trying to get some fragment of humanity on their way to a new home before it happens.

    2. Deliberate isolation, where some group sets out on an interstellar journy just as much to get away from everybody else, as to get to the destination.

    The latter scenario wouldn’t take place until such a trip was within the reach of relatively small groups.

    So the only way it’s going to happen is if propulsion technology stalls for some fundamental reason, such that you have a high degree of confidence later ships aren’t going to be much faster. Or if the solar system is settled, and the necessary tech affordable enough, that Kuiper belt colonies just decide that, a tenth of a light year, ten light years, what’s the dif? And head out to get some guaranteed privacy.

    And THAT is how I think it’s going to happen.

  • ljk October 9, 2014, 10:32

    Here are my questions about building a magnetic sail half the diameter of the planet Earth. Note that I am already assuming we will have a permanent and fairly well developed presence in the Sol system to make this even possible:

    1. How easy will it be to collect enough planetoids of manageable sizes to use as building materials?

    2. Will there be enough of these manageable planetoids to build a sail six thousand kilometers across?

    3. How much will this craft cost to build and who will fund this?

    4. Will space corporations be rich enough that they can afford the luxury of a massive sail whose main purpose will be scientific exploration?

    5. Will there be any technological and societal spin-offs to help sell this project? Because going to Alpha Centauri purely for science will only work with a small segment of the populace as it does now and for the foreseeable future.

    6. Could it be used as a weapon in any way?

    7. While Alpha Centauri may not have any intelligent life forms (or even planets at this point), how wise will it be to approach an alien star system with a vessel the size of a small terrestrial planet in the event such a system does have native intelligent life forms?

    Imagine the reaction on Earth if a gigantic spaceship of unknown origin was approaching our Sol system. I am assuming here that the sail will be utilized more than once if we can get the first one built at all. Would we or they believe us if the vessel did all that it could to insist that it is on a peaceful mission of scientific exploration?

  • ProjectStudio October 9, 2014, 11:46

    re: “Image: Interstellar generation ship configured for braking. Credit: Dana Andrews.”

    (Picky) the diagram appears to show the superconducting loop in its ‘normal’ orientation – with loop axis normal (‘in’ or ‘out’ of the page) to the incident solar wind or plasma coming from the target system as the spacecraft begins to slow through magnetic breaking. However the normal orientation will cause a lateral motion (‘up’ or ‘down’ direction as the diagram is drawn), not a breaking effect.
    To achieve a breaking effect, the superconducting loop would be in ‘axial’ configuration, so that the loop would appear edge-on in the diagram, open to the solar wind or plasma incident upon it from the left, and so deflecting incident ions more or less symmetrically.

  • Garry October 9, 2014, 11:59

    So, I would be concerned about a couple of things if the timeline for such a mission were on the order of 50 years or so:

    1) Maintaining political support and funding for such a program over the entire course of the mission. Look at what has happened with NASA after all. And here we have a mission which would have a great danger of having “nothing to report” for lengthy periods of time. Surely we could have a new generation of political leaders come in and/or a shift in public opinion, or an economic crisis back home during that time that could jeopardize funding.

    2) Technological change. Normally the concern is that better propulsion technology would be developed. I would be concerned more about computer technology changing so much that communications could be jeopardized. Even now how easily could we interface with a computer from 1964?

  • Michael October 9, 2014, 12:30

    Now so what that the ship is only going 0.02 c and will be over taken, just configure the slower ship with the ability to dump unneeded systems, fuel etc. and accelerate a much smaller part of the craft (life raft) to the new velocity to be picked up by the faster craft (partly empty).

    @ProjectStudio October 9, 2014 at 11:46

    re: “Image: Interstellar generation ship configured for braking. Credit: Dana Andrews.”

    ‘(Picky) the diagram appears to show the superconducting loop in its ‘normal’ orientation – with loop axis normal (‘in’ or ‘out’ of the page) to the incident solar wind or plasma coming from the target system as the spacecraft begins to slow through magnetic breaking. However the normal orientation will cause a lateral motion (‘up’ or ‘down’ direction as the diagram is drawn), not a breaking effect.’

    The charged particles would not cause an ‘up’ or ‘down’ motion as the charged particles would move around the magnetic bubble equally slowing the craft down, it would be more efficient braking wise to have it axial orientated though.

  • Antonio October 9, 2014, 13:28

    Garry, 2) is no real problem. First and foremost, onboard the starship there is real people, that can learn about new protocols/technology. And, even if it’s an unmanned probe, its designers (and the people in the control room) know how long the trip will take, and can take measures to prevent that the old protocol/technology is forgotten.

  • Antonio October 9, 2014, 14:41

    As for the discussion about the later-ships-will-arrive-sooner issue… Why the later ships have to go to the same destination? There are plenty of places to go. If humanity sends its first spaceship to, say, Alpha Centauri, why will it send another ship there instead of Epsilon Eridani, Tau Ceti…?

    The trip will not be for money, interstellar mining will not be profitable. If the purpose is colonization, why go to a place where you can have problems with other colonists? If the purpose is science, why go to a place that will be studied anyway by another ship? If the purpose is to build a space base from where to explore near stellar systems, why don’t go to a non-explored zone?

  • Andrew Palfreyman October 9, 2014, 16:40

    Someone once wrote that it’s always a bad time to launch an interstellar craft towards an interesting destination, because you’ll end up being overtaken by multiple, ever more capable newer craft. It reminds of the tortoise and hare, and is, as Paul reminds, not a sound way to view the enterprise.

  • Alex Tolley October 9, 2014, 17:28

    @Antonio – I think the reason is the same as it has been throughout history – quality of the world. Unless suitable worlds (for human colonies) are very commonplace, they are likely to be sparsely scattered through space. Thus the nearer ones will be prized because the journey is likely to be more survivable. If a later ship can overtake an earlier one, they can lay claim to it, especially the attractive parts, first. A perfect world 1000’s ly away taking 50,000 years to reach is a lot less attractive than a less than perfect world a mere 10 ly away.

    If you are talking science probes, it still makes sense to overtake an earlier probe to a specific world if the data you expect to receive is going to be better and come back sooner.

  • Brett Bellmore October 9, 2014, 17:41

    Why bother going to someplace twice as far away, just because a shipload of ancients might or might not show up a couple centuries after you arrive? A solar system is a big place, if they don’t break down along the way you’ll find room for them.

    It would be silly to leave a destination uncolonized for centuries just because you were waiting to see if the first generation colonization ship using obsolete tech could eventually manage to get the job done.

  • Astronist October 9, 2014, 20:34

    Absent hypothetical magical propulsion technology and energy sources to power it, the purpose of any manned interstellar mission will be colonisation. The overtaking problem is not a problem unless getting there first is important. Any planetary system is large enough that it would take on the order of 1000 years to substantially colonise it. So even if an earlier but slower ship is overtaken by a later but faster one, there will be plenty of room for the later arrivals unless they are overtaken by more than a millennium.

    Stephen

  • Astronist October 10, 2014, 7:30

    In the original post: “The biggest question I have regards fully closed-cycle biological ECLSS (Environmental Control and Life Support Systems). At a risk factor of 2.5 and 25 years of development, we could deploy these technologies on a generation ship, but will they be tested and ready by late in this century, when the starship would presumably be launched?”

    This is a good example of how different your and my approaches to the problem are. To me this is not a problem at all, because by the time any manned starship is ready to be launched, a large fraction, arguably a majority, of the human population will be living permanently in space and planetary colonies in any case. The starship travellers will both have and need to have an enormous experience base re maintaining life in small artificial environments over multiple generations, including obviously human procreation.

    Why so? Because if we are going to start colonising planetary systems, then it should be obvious that the first one we will colonise will be the Solar System. If we can’t make ourselves at home on Mars and in the asteroid belt, then we have no business sending people to try and do that at poorly known and difficult to access exosolar analogues of those places.

    Again, regarding propulsion: one of the main requirements for any starship propulsion scheme is that it should be of utility for long-range journeys within the Solar System, so that when the time comes to apply it to interstellar flight, it will have a track record and a substantial experience base. But of course people don’t talk about this, because they want to go to the stars now, whether we’re ready or not!

    Stephen

  • Paul Gilster October 10, 2014, 9:40

    Astronist writes:

    This is a good example of how different your and my approaches to the problem are. To me this is not a problem at all, because by the time any manned starship is ready to be launched, a large fraction, arguably a majority, of the human population will be living permanently in space and planetary colonies in any case. The starship travellers will both have and need to have an enormous experience base re maintaining life in small artificial environments over multiple generations, including obviously human procreation.

    I don’t disagree with you, Stephen. Bear in mind that I was describing a specific scenario, the one Dana Andrews was talking about. Namely, what would we do if we wanted to launch an interstellar craft absolutely as soon as we could? But I don’t think we’re likely to do that either. The more likely scenario is what you describe, with growth into the Solar System as the precursor and driver for any interstellar journey. This is why I’m always harping about a system-wide infrastructure as the forerunner of star missions.

  • Mark Zambelli October 10, 2014, 10:30

    ljk says…

    “1. How easy will it be to collect enough planetoids of manageable sizes to use as building materials?

    2. Will there be enough of these manageable planetoids to build a sail six thousand kilometers across?”

    By my calculations the loop would have a circumference of just under 19,000km. Yes the earth’s circumference is nearly 40,000km BUT the total length of wire used in the cables for the Brooklyn Bridge amounts to 23,105km! While it is clearly easier to construct galvanized steel wire than a loop of superconducting wire I think this helps the perspective. So maybe it wouldn’t need many planetoids to provide the raw material after all?

    “4. Will space corporations be rich enough that they can afford the luxury of a massive sail whose main purpose will be scientific exploration?”

    I doubt it, not unless there is another, more pressing, reason. Maybe a consortium of companies/agencies could pool resources (and any cooperation could be viewed as a positive spin-off for the fifth point below)

    “5. Will there be any technological and societal spin-offs to help sell this project? Because going to Alpha Centauri purely for science will only work with a small segment of the populace as it does now and for the foreseeable future.”

    Technology spin-offs… yes and numerous if the project is tackled as the Apollo program was. Societal… hmmm, not too sure other than the hope that all societies would know we are engaged in the grandest undertaking yet and that may mean something. It may at least make us feel as Carl Sagan hoped… we are on a tiny fragile speck and it needs looking after.

    “6. Could it be used as a weapon in any way?”

    The only thing I can think of would be to stow the mag-loop before braking and let the craft become a relativistic projectile. I can imagine that a several metric ton small craft barrelling-in at over 0.2c would make quite a dent on any planetary crust. Leave the loop partially stowed and the area would be that much bigger. If the mag-loop is vapourized in the targets upper atmosphere(?) then the sleet of radiation would damage the surface. However, I’m not a warmonger so who knows? ;)

    “7. While Alpha Centauri may not have any intelligent life forms (or even planets at this point), how wise will it be to approach an alien star system with a vessel the size of a small terrestrial planet in the event such a system does have native intelligent life forms?”

    Very good point indeed. It would be wise to steer the craft to a holding point just outside the system (the deceleration alone would indicate to the natives the object was artificial). If they witnessed our craft undertaking peaceful exploration (ie no mining etc) either before they came out to intercept or we ventured further in-system then this might count for something to them. Or make harbour at one of their uninhabited/uncolonised planets to allay fears we were coming right at them. Try signalling them with radio, laser or even with rudimentary semaphore using the loop (prime number maths a la ‘Contact’ might suffice… stow the loop and redeploy a prime number series of times (or cycle the magnetic field in the loop so it ‘pulses’) well before arrival so the locals have plenty of warning. I’m hoping they would understand that we weren’t engaged in some sneak-attack if we make our presence known well before arrival and make sure we’re not aimed right down their throats/ingestion tubules/nourishment pod-assemblies or whatever passes for their cake-holes on their homeworld. I wonder if that might work for us if the tables were turned.

  • Ron S October 10, 2014, 12:01

    I think a lot of the concern about propulsion evolution resulting in the possibility of overtaking earlier, slower craft is misplaced. It isn’t a race.

    Consider an unmanned exploration probe. If a later, faster probe can overtake it that’s a good thing! The faster probe can reconnoiter the target system and return its findings, which can then be used to adjust the earlier, slower probe’s mission to better effect. It can therefore get closer to interesting objects, and since it is moving more slowly can spend more time studying those objects.

    Consider a manned colonization craft. There would be little reason to overtake an earlier, slower craft unless it’s to rescue or take pity on them. More likely the newer, faster craft would be directed to other target systems that are may be even further away, and so well-matched to the its higher speed. After all, if colonization is the objective you want more targets.

  • Brett Bellmore October 10, 2014, 14:33

    “There would be little reason to overtake an earlier, slower craft unless it’s to rescue or take pity on them.”

    I think this is clearly wrong. The earlier, slower craft will undoubtedly be sent to the nearest destinations. Picking a different destination means a substantial increase in travel time, which by any plausible means will be extremely long.

    So, you’re going to double your travel time just because some ancient rustbucket might show up a few hundred years after you? Or might not, being after all an ancient rust bucket.

    I don’t think your reasoning works until we face a surplus of equally desirable destinations at roughly equal distances, which is to say, maybe in the second or third wave of colonization.

  • Ron S October 10, 2014, 19:28

    Brett, I was not promoting that view. Read the next sentence I wrote.

  • Eniac October 10, 2014, 21:21

    Brett:

    I don’t think your reasoning works until we face a surplus of equally desirable destinations at roughly equal distances, which is to say, maybe in the second or third wave of colonization.

    There will never be a greater surplus of desirable destinations than there is now. From the point of view of a boundary colony, the best they can hope for is half a sky full of available targets. The other half will be occupied by Earth and its other colonies. The situation we have here on Earth, now, with an entire sky full of targets, is unique and will never happen again.

  • Antonio October 11, 2014, 5:06

    ljk wrote:

    “7. While Alpha Centauri may not have any intelligent life forms (or even planets at this point), how wise will it be to approach an alien star system with a vessel the size of a small terrestrial planet in the event such a system does have native intelligent life forms?”

    Remember that the ship will be mostly empty space. It’s just a small vessel with a long cable hanging around. I doubt even we can detect such a ship beyond Mars orbit.

  • Joëlle B. October 11, 2014, 6:22

    @Norman Wells

    I don’t know how to feel about the fact that most people directing their energy towards blasting nuclear farts into the dark could be focusing on what the discoveries of the past century mind-blowingly imply and are not. Once we get to a star system with sentient aliens (or they get to us), an attack to our spacecraft is probably going to be the least thing, of many other threats, we would have to worry about. We may brush off the imaginary ideas we conceive in science fiction as limited to the imagination–but forget to ask where does our imagination come from?–What allows us to have such daring lucidity of thought?

    [People are unwilling (or confusing bias with skepticism) to admit: Yes, the probability subsists (very really) of aliens that can tunnel through walls, read your mind, possess your body, cast “spells”, teleport, shape-shift, be zombies [moreso than in the current sense per the ambiguous measurement problems] and do many other (infinitely diverse) things our naivety shall lead (and possibly destroy or amend) us into. Very exciting; altogether swell… but just between you and me, so we don’t get labeled as crazies, k?]

    @Stephen has hit some home runs, although I do believe that whether or not people are “ready” becomes irrelevant in a system such as ours, where one must sometimes make do with opportunities as they arise, whilst beholding limiting circumstances as time, capability, and synergism persist [permit]. The magical propulsion technology and energy sources exist to enable reasonable travel times to places where colonization can occur in a natural, rather familiar manner, on Terrabiologically-friendly worlds, conversely in the face of the possibility that terraforming proves just as, if not more absently hypothetical and magical. Our solar system has the resources to substantiate either, or, and both… Meaning, we can have our cake and eat it too, if colonization is the goal–seed, probe and weld the universe in every direction, propagating each and every unique idea. The ethical issues should be up to each individual [group] and their prime directive; forget the politics and let nature take course as intended. If there are the means, by all means do it. We are a visual species: most of this madness we pitch ends up serving one single, noble purpose–to inspire. Finally, education is key, ensuring each new generation is equally adept at maintaining extraterrestrial habitation. Physical information must become second nature, like the language(s) one speaks, for any of this to last.

    I strongly recommend giving these films a watch, touching on ideas of what exactly does identity, risk and assumption mean in our universe?–Are our preemptive desires, impatience, apathy and intuition driven from within, or by some external influence we stand obliviously to? In our work towards expanding the human culture beyond Earth, whose interests are we acting upon?–our own?–societies, via pressures and fear?–others we care for? Or is there a much bigger picture to frame, requiring deeper questioning?

    http://sonyclassics.com/moon/trailer.html
    http://erbpfilm.com/film/upstreamcolor#
    http://www.focusfeatures.com/the_signal
    http://www.coherencethemovie.com/

  • ljk October 11, 2014, 18:05

    Antonio said on October 11, 2014 at 5:06:

    “Remember that the ship will be mostly empty space. It’s just a small vessel with a long cable hanging around. I doubt even we can detect such a ship beyond Mars orbit.”

    So you mean our starship might look like a giant lasso and the target world will think of itself as some kind of space calf to be captured, roped, and hogtied?!

    If there is any truth to all those cattle mutilations being done by aliens, perhaps they will think this is some kind of revenge on our part. :^)

  • Mark Zambelli October 14, 2014, 14:01

    Joëlle B said…

    “I strongly recommend giving these films a watch…”

    Thanks for those links. ‘Moon’ is excellent (I’m glad David Bowie’s son changed his name). I have it on DVD and the the soundtrack is wonderful. ‘The Signal’ I knew about and am looking forward to. ‘Coherence’ looks very intriguing and will try and watch asap. As for ‘Upstream Color’ I have to thank you especially. I knew nothing about this and to my delight it’s the second film written and directed by Shane Carruth after his astounding 2004 ‘Primer’ which I have and is not only the most confusing (in a good way ;) ) time travel film ever (fear not, some kind persons have put explainers online) but it’s one of the best I’ve seen. Thanks again Joëlle.

  • Mark Zambelli October 14, 2014, 14:11

    @ljk

    “If there is any truth to all those cattle mutilations being done by aliens, perhaps they will think this is some kind of revenge on our part. :^)”

    Ha ha… hope so, they deserve it :) unless they’ve been doing us a painstakingly slow and ineffective favour fruitlessly trying to help curb our methane probs. Still, I need cow-juice for my cornflakes so let ’em have it.

  • Steve White October 17, 2014, 14:03

    Just to throw in my 2 cents, if it’s even worth that much re this comment: “For one thing, it’s a generation ship, so entire lives will be spent in cramped quarters…” For one thing, the effects of this can be mitigated at least somewhat by “Virtual reality” both in day to day activity that might be work related, and in just the playful, relaxing and having fun necessary for most living creatures.

    True, it would be an illusion, but it can create the feeling of freedom and wide open spaces and some such virtual realities could be designed just for this type of mission and environment. That combined with the needed work-outs could maintain both the intellectual, emotional, and physical health needed for a long voyage.

  • Trevor October 17, 2014, 20:10

    Paul Gilster writes:

    “…the prospect of being overtaken by a later, faster ship is always there. But that’s not the point. 18th Century voyagers with a yen for the unknown could have waited for the age of steamships, but how could they have anticipated it?”

    Furthermore, would the steamship have ever come to be if some earlier generation had not first experimented with a dugout canoe?

    The idea I’m trying to convey here did get some treatment in the comments to the previous CD article linked above (https://www.centauri-dreams.org/?p=915). But often it goes unmentioned.

  • Joëlle B. October 19, 2014, 1:05

    @Steve White

    That’s a good idea, you may be interested in MICA. Unfortunately for us, the project was disbanded, due to lack of interest in the academic community. ;(

    http://www.mica-vw.org/wiki/images/e/e0/MICA_AAS_June09_small.pdf
    http://arxiv.org/abs/1301.6808
    http://www.mica-vw.org/wiki/index.php/Meta_Institute_for_Computational_Astrophysics

    Other endeavors such as ‘Astronomy Learning in Immersive Virtual Environments (ALIVE)’ by Dr. Ka Chun Yu is what MICA was to a lesser degree, but seems to still be active. http://www.dmns.org/science/museum-scientists/ka-chun-yu

    Immersion is an extremely valuable tool and though the technology is still developing, spreading the word and getting more people involved will contribute to its growth and to the possibilities of VR; it’s really amazing stuff and could even have beneficial implications toward our social behavior as you noted–

    Virtual Superheroes: Using Superpowers in Virtual Reality to Encourage Prosocial Behavior
    http://vhil.stanford.edu/pubs/2013/rosenberg-plos-virtual-superheroes.pdf
    http://vhil.stanford.edu/projects/

    http://en.wikipedia.org/wiki/Immersive_technology#Research_and_development