Incredible journey: Can we reach the stars without breaking the bank?


Voyager 1, our civilization's furthest and fastest emissary into space. Traveling at 17 kilometers per second, Voyager 1 still would take some 73,000 years to reach the nearest star.

Yesterday, we talked about which stars might be the most important ones for the near future of the search for habitable and inhabited planets. All the stars I mentioned are relatively close by and pretty bright, and some of them are already known to have planets. If and when potentially Earth-like worlds are found around these or other nearby stars, astronomers will begin lavishing them with attention in a process of discovery that will span generations. In all likelihood, entire careers and even subdisciplines of astronomy and planetary science will emerge from studying all the data we can remotely gather from a handful of promising worlds scattered among the nearest stars. If we are extremely lucky, and find signs of not only extraterrestrial life but also extraterrestrial intelligence, the consequences will spread beyond our sciences to shape and change our religion, philosophy, literature, and art.

And, if we did locate another pale blue dot circling a nearby star, for many people the next logical step would be to attempt to send people or machines there for direct investigation. It sounds simple enough, to send a spacecraft from point A through mostly empty space to point B. The Moon hangs shining in the sky along with the stars, and we've already sent explorers there, as well as robotic emissaries to all the solar system's planets. Reaching the stars shouldn't be that much harder—but it is.

Consider the problem from the simple viewpoint of velocity. It's easy to forget that until very recently, the fastest anyone had ever traveled on planet Earth was almost certainly about 200 kilometers per hour (kph), the terminal velocity of a plummeting human form past which air resistance impedes further acceleration. But then our species learned to build machines that use the fossilized sunlight in coal, gas, and oil to go even faster.

In 1906, a Bostonian named Fred Marriott finally surpassed the millennia-old record—and lived to tell about it—traveling over 200 kph in a steam-powered car across the sands of Daytona Beach, Florida. Scarcely forty years later, a West Virginian test pilot named Chuck Yeager flew a rocket-propelled plane at more than 1,000 kph, faster than the speed of sound. A decade after that, gargantuan rockets were accelerating men and machines to nearly 28,000 kph, fast enough to orbit the Earth and gain a god's-eye view of the planet. That's how we sent astronauts to the Moon, and robotic probes to other planets. Surely we can go even faster, and undertake interstellar voyages.

But space is vast, and even the distance to the nearest star is mind-boggling. Let's say the Sun is the size of a large orange, 10 centimeters in diameter. Place the orange on the ground, walk a bit more than 10 meters away, and you're in Earth's orbit. Finding our planet might prove challenging—it would be the size of a millimeter grain of sand. The walk out to Pluto, a speck of dust ten times smaller than our sand-grain Earth, would be nearly a half-kilometer, and along the way you'd be lucky to encounter any of the planets: Even the largest, Jupiter, would be no bigger than a small marble.

From Pluto in this scale model, to reach the nearest star system, Alpha Centauri, you'd have to travel some 2900 kilometers: roughly the distance between Memphis and San Francisco, or about how far you'd have to dig straight down into the Earth before reaching its outer core. At this scale, light, the fastest thing in the universe, would travel through space at just over 2 centimeters per second. In actuality, light travels at 300,000 kilometers per second, and requires nearly four and a half years to reach Alpha Centauri from our solar system.

Today, the fastest humans on Earth and in history are three elderly Americans, all of whom Usain Bolt could demolish in a footrace. They're the astronauts of Apollo 10, who in 1969 re-entered the Earth's atmosphere at a velocity of 39,897 kph upon their return from the Moon. At that speed you could get from New York to Los Angeles in less than six minutes. Seven years after Apollo 10, we hurled a probe called Helios II into an orbit that sends it swinging blisteringly deep into the Sun's gravity well. At its point of closest approach, the probe travels at almost 253,000 kph—the fastest speed yet attained by a manmade object. The fastest outgoing object, Voyager I, launched the year after Helios II. It's now almost 17 billion kilometers away, and travels another 17 kilometers further away each and every second. If it were headed toward Alpha Centauri (it's not), it wouldn't arrive for more than 70,000 years. Even then, it wouldn't be able to slow down. Of the nearest 500 stars scattered like sand around our own, most would require hundreds of thousands of years (or more) to reach with current technology.

Space and Ships

Part of the problem is rocketry—an inescapable fact of accelerating by venting material out of a nozzle is that it's not terribly efficient. Not even accounting for food, water, and other consumables, you must carry all your fuel along with you, and the faster you wish to go, the more fuel you'll need—fuel that itself requires additional amounts of fuel to accelerate the additional mass. We've already almost maxed-out the velocities attainable through Apollo-style chemical rockets. But even so, there are no insurmountable physical barriers preventing people and machinery from going much, much faster than the pioneers of forty and fifty years ago. A small, scattered vanguard of idealistic scientists and engineers around the world still obsessively concoct new ways of harnessing more energy, of achieving more velocity, of going faster and farther than anyone has ever gone before. Maybe the stars are within reach.

We already know how to build speedier and more efficient rockets powered by electricity instead of chemicals, but they won't do much to get us to nearby stars. For that, only a handful of schemes could suffice. Some researchers suggest building rockets fueled by antimatter, an energy source so potent that the amount required to send you on a month-long crossing to Mars would be measured in grams. Others call for constructing gossamer-thin thousand-kilometer-wide "sails" in space, which would ride on powerful laser or particle beams out of solar system. These options and their more exotic variations theoretically offer velocities that are a significant fraction of the speed of light.

Sadly, while the physics may be on our side, the economics aren't: Based on present production rates and costs, producing and storing enough antimatter to fuel an interstellar mission would quite possibly bankrupt the planet. As for an interstellar sail, such an endeavor would dwarf the largest single piece of space-based infrastructure yet built, the International Space Station, a construction project that has so far cost an estimated $150 billion. Constructing an interstellar sail would probably cost far more—and that's not including the truly astronomical electric bill associated with powering the multimillion-gigawatt laser that would need to shine on the outbound sail for years on end.

At present, the most economically viable fast boat out of the solar system would probably be a spacecraft propelled by regular pulses of detonating atomic explosives. We do, after all, already have plenty of nuclear bombs lying around for no other real purpose than destroying civilization. Perhaps it's not unreasonable to co-opt them for a more productive endeavor. The US government actually funded a study of the concept in 1958, an ambitious program called Project Orion that seriously proposed, among other things, building a nuclear-pulse spacecraft that could send humans to the moons of Saturn as early as the 1970s. But legitimate concerns over radioactive fallout and the dual-use possibilities of miniaturized thermonuclear explosives forced Project Orion's eventual cancellation.

Flying High

A more recent effort to design a nuclear-pulse spacecraft began in September 2009, and is called Project Icarus. Though, to be fair, Icarus itself is based on another highly regarded study, the 1970s-era Project Daedalus, named after the mythological craftsman who flew free from imprisonment on wings he constructed from feathers and wax. Both projects plan spacecraft that would voyage to the stars propelled by thermonuclear fusion.

Fusion occurs when nuclei of light elements like hydrogen or helium are slammed together with such force that they merge, releasing a flood of energy. It's a process that creates and destroys: It's what gives hydrogen bombs their fearsome power, but it also is how stars shine, glomming together light nuclei in their cores to form heavier elements. Stellar fusion is what made the calcium in your bones, the carbon in your DNA, and the oxygen that you breathe.

If fusion reactions could somehow be used in a propulsion system, they could accelerate a spacecraft to perhaps 10 percent the speed of light. Daedalus envisioned replicating that pressure and heat via arrays of high-powered lasers that would focus on small fuel pellets, compressing them past the fusion threshold and channeling the resulting plasma through a magnetic nozzle to produce thrust. The Icarus team is considering that approach, but has yet to decide on its thermonuclear propulsion method of choice.

Like Daedalus before it, Icarus is a project run entirely by volunteers, scientists and engineers who spend their idle time dreaming of starflight and performing laborious calculations to learn how it might be practically achieved. But unlike the Daedalus volunteers, who relied on the liberal use of slide-rules, brand-new HP-35 calculators, and an occasional sketch on the back of a bar napkin, the Icarus team is leveraging the power of more than 30 additional years of technological progress. Our advances in velocity may have petered out over the past few decades, but our prowess in information processing and communication has steadily accelerated.

Each individual volunteer on the Icarus team today could marshal more computing power than was available to most nation-states in the 1970s, and can electronically access the bulk of the world's accrued scientific and technical knowledge within seconds. Rather than gathering in pubs, they are formulating their starship design via internet telephony, private messaging forums, and the occasional post on the official Icarus blog. Still, while anyone can crunch numbers, actually building a starship would consume a large chunk of the Earth's entire economy, and likely would require creating massive economies off-world.

In the Daedalus plan, for instance, constructing a nearly 200-meter-long, 4,000-metric-ton spacecraft in Earth orbit was actually the easy part, nevermind that such a ship would be roughly the same size as one of the UK's Queen Elizabeth-class aircraft carriers. The harder task was acquiring 50,000 metric tons of the necessary thermonuclear fuel, an isotope of helium that is vanishingly rare on Earth. The Daedalus solution was to harvest the fuel from gas-giant planets like Jupiter, by building and operating a fleet of balloon-borne robotic extraction factories in their atmospheres. In other words, the easiest way the Daedalus volunteers found to fuel their starship was, in effect, the industrialization of the outer solar system.

Additional obstacles abound. Traveling at a significant fraction of light-speed can be compared to staring down the barrel of a gun: Running into a small piece of dust, or, heavens forbid, a sand grain, could cause catastrophic damage. The preferred Daedalus countermeasure was a 50-ton beryllium shield placed at the ship's prow. Even if no damaging impacts occur, a starship on a mission of decades or centuries would still require maintenance as parts and components wore out or broke down. For Daedalus, the solution was to pack a number of autonomous robotic wardens onboard the spacecraft to repair damage as it occurred. Creating such artificially intelligent robots capable of tending a starship for decades on end might be a bit more difficult than designing a Roomba to autonomously vacuum your living room.

And all that effort would only send a 500-ton payload, sans humans, strictly on a one-way flyby of a star. There would be no slowing down, stopping, or returning home. The Daedalus probe would fly through the alien star system in only a matter of hours, gradually trickling data homeward via a parabolic radio antenna. After absorbing untold treasure, time, and talent to reach another star, the Daedalus starship would have sent back scarcely more than the cosmic equivalent of a postcard. Icarus has upped the ante: The team intends to design a starship that can enter orbit around its target star, perhaps to monitor any potentially habitable planets there, and then, somehow, send large amounts of data back to Earth.

Suffice to say, engineering at these scales makes "rocket science" look like child's play.

Even further, consider the disruptive, unanticipated effects of the technologies a project like Icarus currently uses—not even including the ones it hopes to eventually employ for its starship: The ubiquitous computing and information networking that now allows Icarus to break out of local pubs and stretch across the world also seems to be turning many people's focuses inward, simultaneously connecting and unweaving the world. The velocity of our technology may ultimately be too fast, rather than too slow, and like the Daedalus probe of yore, could accelerate past its target in a flash, never to return. In other words, we could all too easily become lost in the virtual worlds we make for ourselves, and lose interest in the stars. Or, more probably, we could squander our resources and experience profound and irreversible technological regression. Sometimes, I pessimistically hold with some combination of these two extremes.

Given the magnitude and number of extreme technological and economic challenges that must be overcome to achieve starflight, it's difficult to imagine what, in fact, a civilization capable of interstellar travel would look like. Probably not much like us--more than anything else, projects like Icarus and Daedalus seem to tell us that we are presently as distant from interstellar travel as the stars are from Earth. And, at least until our culture's prioritization of short-term profit once again aligns with pushing the limits of the ultimately possible, that's likely to remain the case.

Perhaps someday one of these starship designs will take us out of the solar system on voyages to other living planets, other cosmic oases, strewn among the stars. Or maybe all the methods conceived today will in the fullness of time bear no more resemblance to actual starships than airplanes have to birds. Either way, it's worth remembering that the 100,000-year duration of interstellar voyages we can undertake right now is but the blink of an eye in cosmic terms. It may actually be more effective to adapt our expectations to those timescales, and to attempt to master such long-term planning rather than trying to brute-force our way to Alpha Centauri.

In expanding outward into space, patience, not velocity, may be the greatest virtue. After all, we're already on an interstellar spacecraft called the Earth, sailing with the Sun and its retinue of other planets around the Milky Way in circuits lasting 250 million years. Only by carefully preserving and cultivating the relatively bountiful and accessible resources of our planet and the solar system will we ever escape their confines. For now, it's wise to reflect that in our headlong rush to go ever faster and farther, we may only be fooling ourselves.



  1. As if late capitalism wasn’t setting fire to our planet fast enough already. Lets keep the communication satellites – even a decent telescope for the astronomers to satisfy their curiousity with – and then decide how much resources have to be wasted on the rest of the space program before it should be considered a crime against humanity.

    People that organise space tourism should be tried at the Hague.

    1. Speaking of wastes, did you know biologists are doing experiments on flies, and physicists hitting smashing objects together? Maybe when you vote, make sure the government knows that money should be going to the Iraq war instead. Because if you pour out the bucket that goes into understanding the universe, that’s the ocean that will soak it up, not help to the poor.

      It amazes me how this trivial program, which costs less than the inefficiencies in the military let alone something like corporate hand-outs, is brought up in nearly every discussion of wasted money. It’s so far out of proportion to its costs that it’s hard not to conclude the reason is less fiscal prudence, and more hatred of knowledge.

    2. Maybe we should sue manufactures for “littering” if they manufacture any goods with less than heirloom quality. Overall, we would waste far less money on useless junk, and could afford a space program!

      Also, the environment would thank us.

  2. People who fail to see the value of space exploaration should be forced to stay at home without a computer so they can’t force their jaded and ill-informed views onto the rest of society.

  3. “And, at least until our culture’s prioritization of short-term profit once again aligns with pushing the limits of the ultimately possible, that’s likely to remain the case.”

    So sad!

    The really frightening thing about all of this is that all that government and military funding is imaginary: no resources already in use would be unduly diverted, no employees or materials need to be switched.

    If the US government really wanted to do this, it could.

    It will soon be affordable for China, should she wish.

    I vote that the Chinese reach the stars and eventually let us play again too.

  4. TSE > SEF

    I think you’re in the minority, TSE, about wanting to permanently tie our species to this particular ball of minerals.

    1. I think SEF said it a little too boldly maybe. Space is infinity interesting. It’s worthy of endless staring, thinking, reading, and dreaming. It would be amazing to travel great distances into it. I’d have a hard to impossible time turning down an offer to visit space.

      Unfortunately… Spending and pushing resources towards it is subtly horrendous and lovably naive. It’s liberating to get big eyed thinking about it, but action towards that goal through capitalism is going to entail the suffering of millionsx100+-x and a revolving circle of wars of various shapes and sizes. Not only that, it’s plain depressing to assume that human nature would remain stagnant for that long.

      Right now space programs of that magnitude are maintained by money and powerful people. In order for the rate of technology improvement necessary to remain at a constant rate these hierarchies cannot be disrupted, only fostered, therefor existing have and have not ratios must be maintained to sustain it.

      Space is awesome but we’re at the place we evolved from and with and we’re destroying it. It’s nice to fantasize and theorize about it but it’s a crime to gamble at such potentially high odds when there’s so much else to solve right here.

      It would be really interesting to have a formula done up. Your playing with the odds that we survive as a species long enough to attain such technology and if we have survived you could assume we abandoned material based cultures and hierarchy based societies. Or you could assume we tragically remained in hierarchy based, ‘have and have not’ societies (which would substantially increase the odds we wouldn’t survive long enough for these elaborate nuclear propelled ships.) Nuclear based ships brings up a whole new set of odds to deal with, whether or not the technology would actually work, or just start us off down the line to the next one and so on. If you attain the ships you’ve got to deal with odds of failed missions (i’d say quite high odds). Odds of the planet being inhospitable, time it takes to evolve further to a society where we can make use of the planet, and all the additional odds that entails. odds odds odds. time time time. Let’s fix what’s here. It’s a bummer that the probability, theory, and mechanics of a stateless world is given less attention than the mechanics of settling other galaxies. I’d say where making steady strides at dissolving and looking down upon coercion based relationships – feudalism – fascism – slavery – womens rights – children’s rights – gay rights.

      One’s a euphoric fantasy and the other’s a break from routine and an upwards struggle. Global consciousness defeating hierarchy and competition based societies is a much more realistic and infinitely more desirable goal. Let’s invest the effort into that instead. Space is dope. Keep the space stories and theories coming. Just please never support excessive spending on it. The power that money holds is the yoak around the necks of millions.

  5. Great read! The thing of it is, almost any discussion of interplanetary (let alone interstellar) travel has to begin with the cost to orbit. When it’s $10K a kilogram to get things into space, it’s very hard to get anywhere else. The best thing — and thing about which I am most excited about in just about all of human endevaour — is the growing private sector for space access. No idea if any given one of these things will work to lower costs (although I believe they will), the idea that folks will put out their own money at a shot at making a ton of money in space is good for everyone and everything.

    I have no possible understanding of what SEF is even saying. That we should just curl up in a fetal position and ignore the rest of the universe? Listening to Emperor Ming, you are. “Pathetic Earthlings, hurling yourself out into the void with out the slightest inkling of who or what is out there. If you had any understanding of the true nature of the universe you would cower in fear from it.”

  6. House arrest for an opinion you disagree with? Your use of the word force displays an ill informed understanding of its sense. This is ironic.

    1. “Crime against humanity”

      Throw your computer in the trash. You don’t deserve the benefits of exploration.

  7. Thanks for clearing up your own confusion LordDon. I think the article does a good job of introducing the irrelevance of all opinion on the matter, regardless of whether it is an opinion of the minority or the majority.

    Industrialisation of the outer solar system is not remotely feasible. On this particular ball of minerals we are all stuck. Coming to terms with this fact is considerably more dignified than naively embracing the consequences of its denial.

    The 20th century remix of a 19th century notion of empire is what is really jaded here. A flag on the moon doesn’t mean that America owns it or that the moon is something worth owning.

    The profound question is what human civilisation should be trying to achieve. I enjoy science fiction but 2001: A Space Odyssey is nonsense here while Solaris is key.

  8. This article, while containing some interesting comments, uses an a lot of words, without actually saying, that even if we could achieve a speed of 10% of the speed of light, a voyage to the closest, < > inhabited place, would be thousands of years and not within the realm of likely human achievement. Indeed, even without travel, a conversation over speed of light communications, would take at least lifetimes between answer and response.

    Given the impracticality of such an endeavor, we would be better off setting our sights to less ambitious endeavors in space, and spending more of our funds upon improving the lot of those who live on Mother Earth.

  9. SEF – Industrialization of the solar system is not feasible at $10K a kilo to orbit. It is inevitable at $50/kilo to orbit. And questionable at some point in the middle. I don’t expect to see anything close to interstellar traffic before I pass this mortal coil, but I’m not so convinced that I know everything to suggest it will never happen.

    And if you want a long-term happy Earth civilization, what’s better than digging out Helium-3 from the Moon to run clean fusion plants hither and yon?

  10. That was a fascinating read, Lee. Precisely what I was hoping you’d post about.

    Sef, your attitude is pretty defeatist. You’re giving up at the foot of a barrier that looks insurmountable to you, but you’ve forgotten about the many barriers we’ve already passed, barriers that looked insurmountable just decades or centuries ago: steam- and internal combustion-powered vehicles, computers, lasers, flight, space flight! There were likely plenty of people who scoffed at all of those things, but thank goodness for those who persevered.

    1. “Sef, your attitude is pretty defeatist. You’re giving up at the foot of a barrier that looks insurmountable to you, but you’ve forgotten about the many barriers we’ve already passed, barriers that looked insurmountable just decades or centuries ago: steam- and internal combustion-powered vehicles, computers, lasers, flight, space flight! There were likely plenty of people who scoffed at all of those things, but thank goodness for those who persevered.”

      i find it really strange how so many people would feel this way about space but so few about the human condition. it’s great logic.. about ignoring barriers. they fall suddenly and often with little pretext. let’s apply some of this idealism to society rather than to planets billions of light yeas away that may very well have chemical compositions that want nothing to do with us

  11. I don’t think we should abandon space exploration altogether, but I do think there are intractable problems other than the vast distances involved. We’ve shown ourselves to be poor at managing complex systems. It can be argued that once a system reaches a certain level of complexity, it isn’t just hard to control, it’s theoretically impossible to control. The best we can do is create the convincing illusion that we’re in control. Don’t make me say Three Mile Island.

    That’s not an argument against trying, but we have to keep it in perspective. Building a complex system that has to remain in service for 70000 years is like buying a really expensive lottery ticket. If it can’t be justified at a near-certain probability of failure, it can’t be justified.

  12. What a great article. No matter how many Americans cry out that Columbus Was A Dope, the fundamental exploratory nature of humanity will win out.

    Viewing it on a galactic time scale, we’ll be out of here in the blink of an eye.

  13. Sef writes:
    Industrialisation of the outer solar system is not remotely feasible.

    And your source for this opinion would be … ?

    To inhabit and industrialize, one needs people, mechanisms, raw materials (for both people and mechanisms), and energy. Raw materials are found everywhere.

    The only thing the outer solar system does not have is an abundance of solar energy. Large, very thin, very lightweight mirrors accomplish concentration of solar energy. The mass fraction of an energy collection system dedicated to concentration necessarily increases the further out you go, yes, but it’s not overwhelming until you get to Neptune-ish. Technically viable solutions for further out exist, though mass of collector dominates once you get out to fractions of a lightyear.

  14. You forgot the idea of actually moving the solar system via manipulation of the sun’s mass.

    Turning the entire solar system into a space ship that we could move through space to visit other star systems.

  15. I think if “we” ever make it to other star systems, the “we” in question will probably be mind uploads rather than flesh-and-blood primates. This would cut down the payload mass immensely, and uploads also wouldn’t have to worry too much about the length of the trip since they could alter the subjective rate at which they experienced time. Plus if we’re really attached to the idea of biological humans living in other star systems, the ships could also carry some frozen embryos, then on arriving at a suitable planet the uploads could build artificial wombs and raise the children there.

    Even if mind uploading technology existed, though, getting a ship up to relativistic speeds (even 10% of light speed) might be pretty difficult…Project Daedalus assumed fusion explosions initiated by powerful lasers (or electron beams) which I think would be pretty far beyond anything that can be built today, might it turn out there are basic physical problems with building a laser of sufficient power whose mass isn’t too gigantic? One alternate idea for interstellar travel that keeps the ship light is to have a ship pushed along by some sort of beam from the solar system–perhaps a huge laser pushing along a solar sail type craft, or perhaps a stream of pellets of some kind accelerated to fast velocities by a giant mass driver. One interesting variation I’ve seen is that the pellets might include some basic nanotechnology that allows for course correction, so that the beam doesn’t suffer from the spreading effect that a natural laser or particle beam would. Another variation is to make the pellets themselves into miniature sails that are continually pushed by a laser from Earth…both ideas are discussed in this post from the centauri-dreams blog, and also on p. 142-146 of the Centauri Dreams book, you can see this section on google books here.

  16. Constructing an interstellar sail would probably cost far more—and that’s not including the truly astronomical electric bill associated with powering the multimillion-gigawatt laser that would need to shine on the outbound sail for years on end.

    I thought one of the points of solar sails was that, once you built them, all the energy was free: from the sun. Why would you need a multimillion-gigawatt laser?

    Of course, all my knowledge is from A.C. Clarke’s The Wind from the Sun, so there is much I don’t know.

    1. Stars radiate their power in all directions, and the intensity drops off according to the inverse square rule. In order to still be able to use a solar sail beyond the heliosphere, we’d need to line up the light in parallel beams the way a laser does.

      (I suppose we could build an enormous focusing mirror instead, but that would be silly.)

    2. I thought one of the points of solar sails was that, once you built them, all the energy was free: from the sun. Why would you need a multimillion-gigawatt laser?


      If you can find it, read Rocheworld (or The Flight of the Dragonfly) by Robert Forward.

    3. That’s only true up until you get past the heliopause- after that, no more solar wind.
      Plus, the acceleration would start out really, really slow- the more power you can apply to the sail, the faster you can accelerate.

      As to the need for very long term planning to justify space travel- I suspect that will take care of itself, but not in my lifetime.
      For 400 years or so, human energy use has risen by an order of magnitude per century. At that rate, in 300 years, we’ll be consuming all sunlight that reaches the earth- no more local room for consumption growth.
      The human body is a physical system- in time we will learn to repair all damage to it, vastly expanding our lifespans. The brain is an informational system- in time we will learn to upload minds into more durable computers.
      If people knew they were likely to live many thousands of years, but had no room to grow without space travel, then they’re going to try and figure out space travel. They may take a thousand-year or so detour to build a Dyson swarm, but that’s infinitesimal on a cosmic scale.

  17. Sef writes:
    Industrialisation of the outer solar system is not remotely feasible.


    Men might as well project a voyage to the Moon as attempt to employ steam navigation against the stormy North Atlantic Ocean.
    – Dr. Dionysus Lardner (1793-1859)
    Professor of Natural Philosophy and Astronomy

  18. A huge sigh of relief when you mentioned the Long Now Foundation: without considering the human attention span, this whole conversation is right up there with those friendly new-age space aliens that will come in flying saucers to enlighten the tin foil hat club.

    I think it’s a safe bet that by the time humans are up to a jaunt outside the heliosphere, we won’t be at all confused by robot missions vs manned missions. Even to ‘step foot on another world’ may well be something robots get to do, and still have it count.

    I’m less certain that this species will ever get it together enough to do business on these local worlds, never mind the larger neighborhood. And even if it’s ever possible, I’m not sure we would want to.

    Most people I know don’t understand or care about the difference between the dots of light in the sky that are stars, and the dots of light in the sky that are wanderers. If I can imagine a world where this post would matter to them -in a positive way- then I can imagine a world where there’s quite a bit else that’s changed for the better.

    Even Carl Sagan was sort of bitter about the chances that Earth might escape our isolation. He speculated that this planet and this species might not ever be important enough for ET to even talk to us, never mind an actual visit. If *this guy* is cynical about it, I don’t know that I could say much different.

    There’s a lot of reason to believe that Luna is as far as *this* human civilization will ever send humans to. A future human culture that could land on the nearby rocky worlds would be different from ours, in the same way Inuit are different from Dorset.

  19. In a Resource Based Economy, we would be out there already trying all manner of propulsion systems.
    In the current paradigm, money maintains scarcity. See The Venus Project for more details.

    Much love to you all !

  20. How important is the time gap of interstellar travel? A thousand years to send a ship to a star and and a 100 years to send the informatiom back isn’t very long.

    After all, one perspective could be that Darwin decoded a message sent from millions of year ago and changed our world. We as a civilisation still build our lives around documents created 100’s if not thousands of years ago. Archeologists spend their lives reading messages from the past that end up changing our society today. The Antikythera Mechanism was discovered 2,000 years after it was made and has radically changed our perception of human ingenuity. Every day astronomers read messages that are millions of years old.

    Interstellar probes give us the opportunity to send some really cool information to our decendants. Hopefully, they’ll still be interested.

  21. We can easily colonize other stars for a few million dollars … if you are patient and expand the meaning of “we.” “We” can include our microscopic cousins. Lots of forms of life form tough little spores. Bacteria, algae, fungus, even some plants and animals. 1 kg could contain millions to trillions, depending on what you want to send to space.

    The hard part is building small “probes” that can escape the solar system. Spreading a dusting of spores in space cab use bio-warfare tech. You’ll want to send lots of these probes in different directions for insurance. But build them small enough, and you could get a cheap lift to orbit by piggybacking on another rocket.

    Of course our Alpha Centari neighbors might not think this is such a great idea.

  22. Sef writes:
    Industrialisation of the outer solar system is not remotely feasible.

    And your source for this opinion would be … ?

    Sef can’t contemplate such an undertaking, therefore it must not be possible.

    Hopefully, Sef is not in any position to dictate policy to scientific minds.

  23. I have to say, now knowing that there are all those planets out there, it does creep me out that we haven’t seen evidence of extra-solar beings.

    Do they all go inward, obsessed with their own simulations? Do they kill themselves off? Do they have singularities? Fermi paradox stuff…

  24. Project Icarus you say?

    Icarus, son of Daedalus: who in his youthful exuberance flew too close to the sun and melted the wax in his wings and plummeted to his doom?

    Fitting analogy.

    Thank you for the honest article; but the point is made: this rock here is all we get. No new life. No new civilizations. No boldly going etc etc. . .

    I hate to be a downer here, but facts is facts. I mean, look at the humans around you: we can’t even get it together to feed all the people on this planet, and the food is ALREADY HERE! Yet somehow a global culture of aquisitiveness and xenophobia will *Transform!* into one of unity, purpose and vision?

    Hey, if you gotta dream, dream big. It’s the dreamers and explorers that brought much of the great things we have in this world to light (and, ahem, a few of the not-so-great. . .)

    “Or, more probably, we could squander our resources and experience profound and irreversible technological regression.”

    Yeah. That unfortunately seems like a head clearing dose of reality to me.

    Oh well: Excelsior!

    1. This island is all we get. We will never be able to cross the ocean to find another island. We might as well stop thinking about it.

  25. Thankfully space colonization is science fiction. The infection called humanity is quarantined on this dying planet. The universe breathes a sigh of relief, I’m sure.

  26. I for one welcome our robot overlords!

    Humans are not good at populating truly hostile environments, like Antarctica, underwater, or space. Our biological heritage has, at least hitherto, betrayed us. We may change ourselves to be space natives, but more likely it will be our robot successors that populate space.

    Look at the number of humans in space per year between 1960 and today. It doesn’t ever succeed 20. And the growth rate is slow and linear.

  27. We first have to get off this gravity well and move and populate a part of space with more surface area.
    Hydrogen/oxygen rockets have been the standard, but if we use the same components in a different configuration, there might be another, cheaper way.
    Of course, I have a proposal…please see
    for more detail. I’m sure it will be rejected by most, but it still has yet to be tested.

  28. Nice article Lee! Call me an optimist but I am hoping we can get the price-tag for “Icarus” down from what I estimated in a recent blog-post – about half a trillion. But deuterium does seem to cost an awful lot, let alone Helium-3.

  29. I don’t think it’s necessary for us to unite in some kind of utopian global society before we colonise the solar system. The means might be too expensive for even an alliance of nations right now. But 100 years ago, (as others have said) producing the computer I’m writing this on may well have bankrupted the planet. Technology gets cheaper as it gets more sophisticated.

    The primary driving force of colonisation, as it has always been, will be economics. There is trillions upon trillions of dollars to be made out there, all it takes is the means to become cost effective enough. It doesn’t make sense to say that ‘we can’t solve world hunger, so how can we do this?’ European nations were corrupt, diseased, unjust places when they set out to take over the planet. Getting your house in order before you go take over another one is a nice idea, but it isn’t necessary & it simply isn’t how human civillisations operate.

    Essentially *when* it becomes profitable, we will do it, and like all human endeavors it will create as many problems as it does solutions.

  30. Apart from the long, long-away day of interstellar travel (for what?) back to today:

    Is the best we can think of to do with our $150B investment in the ISS to DE-ORBIT it? Is NOONE thinking of ways to, say, push it farther out there for ‘safekeeping’ until we’re ready to make a serious commitment to off-world living?

    It’ll be a looooooong time before we’re able to ‘terraform’ even a small area of any moons or planets. Until that day, ‘space is the only place’. Maybe the serious thinkers should start looking around for visionaries like Gerard O’Neill’s students and ask: What MUST we do? And then *commit*.

  31. @ George William Herbert “And your source for this opinion would be … ?”

    There are different cultural norms of expectation associated with putting forward a formal assertion in an academic paper and making a comment in the comments section of an article on boingboing. Your own comment is also completely unsourced and this suggests an implicit awareness of the relevant distinction in cultural norms of expectation and an inclination to impose a stricter criteria on other peoples comments than you believe your own must meet. This is hypocritical.

    @ Bevatron “Industrialization of the solar system is not feasible at $10K a kilo to orbit. It is inevitable at $50/kilo to orbit.”

    I assume that you’re suggesting that as the cost of getting material into space dramatically increases, mining materials in space will become more economically viable. This doesn’t make a lot of sense. On the one hand, if the shift from $10K to $50K is simply the inflationary devaluation of the currency paid to put things into space over the next hundred years or so then this wouldn’t give us any reason to think that the industraialisation of the outer solar system would become any more feasible with this nominal price increase.

    I therefore assume that you suggest a five fold increase in real terms of the cost of putting kilos into orbit. While such an increase would run counter to the notion that technological improvements to an already mature rocket technology will lead to a slight decrease for future kilo to orbit costs in real terms. Nevertheless, allow me to assume your hypothesis of a five fold increase in real terms in kilo to orbit costs. If getting things into space becomes considerably more expensive in real terms then the economic barrier to entry for mining in space would also increase considerably in real terms. It would therefore become more and not less difficult to establish some kind of space industrialisation or mining program.

    The ISS is the most expensive object ever built and one can assume that any attempt at off world industrialisation will be orders of magnitude more expensive in real terms. Not only would it involve the kilo to orbit cost for heavy industrial mining equipment, it would also involve the orbit to mining area cost for that equipment. It would also involve the same costs for either a transport or manufacturing facility to make it possible to do something with all the newly mined stuff at the mining area. Wikipedia puts the price to mars at $309K per kilo and this figure would presumably rise along with the speculated kilo to orbit cost increase.

    One might think that the barrier to entry costs are worth paying because in the long run the project would pay for itself. What would “pay for itself” mean here? How would mining in space have any payback? Where would materials mined in space be used and for what? Perhaps you want to add the cost of de-orbiting raw materials to earth from Mars or the moon? If mining in space means making it cheaper for humans to do what they already do (e.g. create useful orbiting satellites) then that’s one thing but as we do this already without mining in space I can’t see a reason to overcome the considerable barrier to entry. If you want to use those materials for humanity to do something in space that humanity hasn’t done in space before then that isn’t something that pays for itself, that’s something that just costs.

    I don’t think any new project that would require the commitment of a real percentage of the gross planetary product and a significant fraction of irrecoverable finite resources could ever be of such utility that it would be morally justifiable.

    The question of what space exploration costs in real terms is very relevant to this discussion. As @ HJB stated above “Given the impracticality of such an endeavor, we would be better off setting our sights to less ambitious endeavors in space, and spending more of our funds upon improving the lot of those who live on Mother Earth.”

    @ anon @ Sef “Maybe when you vote, make sure the government knows that money should be going to the Iraq war instead.”

    Tragically, there is no dichotomy between spending huge amounts of money on space exploration and spending huge amounts of money on the Iraq war. Not only are both of these projects already taking place at the same time, they are both produced through the same military industrial complex and they are also both made possible through the very same grotesque centralisation of social economic power. If one thinks in terms of gross planetary product then space exploration is predicated on the exclusion of the third world’s more pressing concerns from the decision making process over how GPP is employed – these phenomena are only possible through a deficit of democratic control.

    @ TSE “Throw your computer in the trash. You don’t deserve the benefits of exploration.”

    As you are no longer calling for my house arrest because you disagree with my opinion I can now consider myself an agent in your ongoing socialisation.

    No one explored space and found a computer. The development of the computer is very much a human accomplishment derived from Leibniz, Babbage and Turing. This of course runs counter to your suggestion that without space exploration there wouldn’t be a computer and that I should for some reason be obliged to give up my computer because I question the moral legitimacy of the space program.

    @ TSE “This island is all we get. We will never be able to cross the ocean to find another island. We might as well stop thinking about it.”

    This comment is a confused in a number of ways. One confusion is the implied presupposition of linear progress. Just because humanity went new places in the past doesn’t mean that humanity will always go new places in the future. Reality may well get in the way.

    There is also a dis-analogy here between islanders not knowing of somewhere equally hospitable and us knowing that there is somewhere quite inhospitable where we don’t especially want to live (the moon, mars, etc.) or knowing that there are probably planets equally hospitable to Earth that are impossible to get to.

  32. Sef, while I agree that spending huge amounts of money on manned space exploration is basically a complete waste (costs far more than unmanned missions because of all the extra payload mass of life support, and any scientifically valuable information that could be collected by a human could also be collected by a machine), I think your arguments about space travel never being profitable miss an important possibility: machine self-replication. If we had the ability to design robotic mining and manufacturing facilities that could do all the work needed to make copies of all their own components and assemble them, then letting just one loose on a large asteroid or some larger body like the moon could soon result in vast numbers of copies without it costing us any further than the original cost of getting the first one up there. And all these automated facilities could also build rockets or mass drivers to send large chunks of mined raw materials (or even finished manufactured goods) back to Earth (as their numbers grew exponentially perhaps they could also work on other huge projects that would make interstellar travel more feasible, like a giant laser to beam energy to sailships or large-scale mining of helium-3 and deuterium in the atmosphere of gas giants). Wikipedia’s article on asteroid mining mentions that a small 1-mile asteroid would contain about $20 trillion worth of metal at present prices, so even if sending the first self-replicating factory up there cost billions this could still be very profitable (though perhaps by the time we have the ability to create such fully automated manufacturing, we will have entered a post scarcity economy)

  33. If more attention was focused on alternative energy sources here on Earth then this problem may naturally find a solution. That’s if we are looking at it properly. We see everything in a linear way but there may be other ways. What if the great outside doesn’t work the same as we do? We are no more than fish in a tank imprisoned here and speculating but only from our own narrow viewpoint. It’s a very short time since we thought that our tiny spec of dust was the center of the Universe! We still only see time as linear. We ignore the reality that we tap into when dreaming. We are infants.

  34. I hate long road trips. Let’s just terraform Europa instead and populate it with our own genetically-engineered aliens- that way our descendants can have an interplanetary war without the hassle of traveling to a distant solar system.

  35. We can break the banks AND explore the solar system. These two noble goals aren’t really interdependant.

  36. I enjoyed the article. It always overwhelms me when describing the vastness of the distances of space.
    But I was sent off in another direction by your wording in the sentence:
    ‘A decade after that, gargantuan rockets were accelerating men and machines to nearly 28,000 kph, fast enough to orbit the Earth and gain a god’s-eye view of the planet.’
    Being sarcastic, I can retort that we can just pray to be granted god’s ability to move instantly through the vastness of space. Or we can just wait until we die and maybe from heaven we’ll see the whole universe without ant effort.

    On a serious note, when I saw the first images of earth from space I never once thought ooh this is how god sees the earth. Rather it was wow, we have people in space and they are viewing the earth as never seen before! Just amazing!

    Introducing god seems to diminish or dismiss what we as human beings have accomplished and what we may be able to accomplish. And it diminishes the amazing and fortuitous series of events that led to our creation and eventual evolution into humankind – a very fragile humankind – that has walked on the moon.

    Believing in god makes those dreams and accomplishments nothing. Just distractions on our path to righteousness and trying be one of the chosen few that make it to heaven.

    Maybe I’m overly sensitive but that one reference just distracted me and lessened my enjoyment of the article.

    (Note: If this post is considered off-track and inappropriate for this blog I apologize. Delete it, but I ask that Lee Billings see a copy of it.)

    Thank you

  37. I believe that advances in the biological sciences will inevitably change our culture’s prioritization of short-term profit. Life expectancies of several thousand years will cause us to adapt our expectations to far longer timescales, completely changing the prevailing economic model.

  38. The 2005 winner of the American Institute of Aeronautics and Astronautics prize in the nuclear and future flight category went to German physicist Burkhard Heim for a paper calling for an experimental test of an astonishing new type of engine. According to the paper, this hyperdrive motor would propel a craft through another dimension at enormous speeds. For instance, a round trip to Mars in five hours.

    “We began as wanderers, and we are wanderers still. We have lingered long enough on the shores of the cosmic ocean. We are ready at last to set sail for the stars.” – Carl Sagan

  39. Several comments have made me despair for the survival of H.OftenANTISapient. Stupidity might fuel a truly limitless power source. The sort of stupid that will implode akin to theoretical models of stellar ignition. The “core” becomes so dense that it ignites from compression density. Literally incarnating the LolCat level expression about stupid so dense that- The Stupid! It Burns!

    In some cases? The burning stupid threatens to burn up our potentially last window off this planet. And yeah- perhaps confining such stupid to a single world makes sense to the inhabitants of all spaces surrounding us. Sucks to be Human from their viewpoint? The concept of H.Sap being the Multidimensional SAP, AkA Punch Line of the bad joke is not how I want to think of us!

    The way to write a different story is to DO IT for real.

    One example being the concept about making enough Antimatter to become an Interstellar Travel Capable species “Bankrupting” the planet. Bullshit. Pure Bullshit. That’s based on a concept of “spending” which ignores the inherent creation of true wealth En Passant while doing some grandiose projects.

    NASA for example. Robert Heinlein wrote Chapter and Verse upon how much ROI our species really got from “space Programs” and Spin offs. Let alone the other continued revenue streams that get handwaved away as “not a factor” even though they ARE a factor.

    GPS? The computer we’re all using to participate in Boing on?

    Oh, some of my thoughts and facts may be vexing to folks that have a closed mind or apparently- a loathing of thought itself. Faith’s a wonderful thing and not to lightly be deprecated insofar as it does not become the demarcation between science and species suicide. Suicide’s antithetical to many faiths. Being anti-science=anti exploration is species suicide. Gee, Logic can interact with Faith to alter our chances of survival. I hope..

    The closer? Antimatter as a power transfer medium- I doubt calling it anything else is accurate, might make our survival assured. Denying our need to get off this single planet is species suicide of a when, not if scenario. What part of- Get off this planet or we all die here is needing further explanation? Dying here may be a thinkable option for some folks. Some of us want to live. Both here and eventually elsewhere. Please don’t try to force your chosen suicide on our species and all others we share this world with..Please?

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