≡ Menu

Starship Century Symposium, London

Oxford-based Stephen Ashworth, who attended the recent Starship Century event in London, obviously took copious notes, as reflected in the piece that follows. Ashworth is a Centauri Dreams regular, a writer and musician who, like so many of us on this site, ponders the big questions of our engagement with — and exploration of — the universe. Here he reflects on the immense challenge of starflight and lets us know how a number of key players now see it. For more of Stephen’s perceptive work, check in regularly at his Astronautical Evolution site.

by Stephen Ashworth

Stephen Ashworth

The new book Starship Century, edited by physicists James and Gregory Benford and with contributions from many active in the interstellar field, takes a broad view of questions of interstellar exploration, the editors told this meeting at the Royal Astronomical Society in London on 21 October 2013. In the first place, why has there been such a surge of interest over the past decade or so, with several new organisations devoted to interstellar travel appearing on the scene? Is the 21st the century humanity will build starships, and if so, why and how?

With Voyager 1 now having crossed the heliopause and New Horizons due to make its flyby of Pluto in less than two years time, finishing the initial reconnaissance of the Solar System, together with a flood of exoplanet discoveries, including the first indications of a planet in the Alpha Centauri system, the time appears right for interstellar exploration to inspire growing interest, James Benford said in his introductory talk.

Yet the task is immense. Before our ancestors learned to ride horses, they were only able to move at a walking speed, on the order of a metre per second. The Apollo astronauts departed from and returned to Earth at speeds around 104 times faster. A cruising speed of a significant fraction of the speed of light, necessary to reach the stars in a reasonable period of time, would require another 104 times jump.

Moreover, in order to make that jump one is running up against the limits of known energy sources. An object flying at 3.75% of light speed possesses the same kinetic energy per kilogram of mass as that released in a thermonuclear explosion.


Image: James (left) and Gregory Benford at the Starship Century symposium, along with a bust of Sir Isaac Newton.

In an article in Physics Today back in 1968, Freeman Dyson predicted that the first interstellar voyages would be possible in 200 years time. However, he recently reiterated that they would still be possible in 200 years time – the familiar tale of an ever-receding goal. Harnessing the immense energies of nuclear fusion reactions, whether for commercial power generation or for rocket propulsion, is not turning out to be easy.

What about the attitude of the public? Benford displayed a cartoon: an ascending sequence of technological achievements in chronological order – a horse-drawn wagon, a car, a locomotive, an aircraft, a space rocket – as rough drawings on a wall. Then you notice that the artist is a caveman. Then zoom out, and you see a cavewoman watching him skeptically, and asking him when he’s going to get the meat in for their dinner. The triumphalist belief in inevitable progress is a nerdish pursuit, and the majority of the public can see no further than the desire to solve their day to day problems.

(However, in The Demon-Haunted World Carl Sagan wrote of the critical importance of those denigrated as “nerds” in making progress possible – his example was James Clerk Maxwell. – Comments in parentheses such as this are my personal reflections after the event.)

For the present, interstellar progress is in the hands of six private groups, all with very small budgets: the British Interplanetary Society (the oldest, founded in 1933), the Tau Zero Foundation, Icarus Interstellar, the 100 Year Starship Organization, the Institute for Interstellar Studies, and most recently the New Horizons Message Initiative. (Given its website and organisation of meetings such as this one, surely Starship Century itself counts as the seventh group?)

Cascading opportunities among a galaxy of planets

James Benford’s brother Gregory presented a quotation about the prospect for development of North America from Thomas Jefferson back in 1812: “It will take a thousand years for the frontier to reach the Pacific.” Jefferson was assuming that colonists would be limited to the capabilities of horse-drawn wagons, yet the steam engine was already a reality, and communications across the continent were vastly accelerated when the trans-continental railroad was completed in 1869.

Martin Rees & Greg Benford

Image: Lord Martin Rees and Gregory Benford.

So Jefferson’s estimate was out by more than an order of magnitude. It didn’t occur to him that opportunities in technology and the economy would cascade to drive settlement of the interior. In a similar way, during the coming century we could be seeing a combination of nuclear rockets, robotics and 3D printing working together to accelerate the economic opening up of the Solar System, which will be essential to exploring beyond it.

Ian Crawford, professor of astronomy at Birkbeck College, London, displayed a plot of exoplanet discoveries made by the Kepler mission (see below), the conclusion of which had to be that virtually all main-sequence stars do in fact have planets of one sort or another. But because it is easier to find them by the transit method, only four are currently known (with varying levels of reliability) within 15 light-years of the Sun, orbiting Alpha Centauri B, Tau Ceti, Epsilon Eridani, and the red dwarf GJ 674.


Image: A new analysis examined the frequencies of planets of different sizes based on findings from NASA’s Kepler spacecraft, correcting for both incompleteness and false positives. The results show that one in six stars has an Earth-sized planet in a tight orbit. Credit: F. Fressin (CfA)

More nearby planets will surely be discovered as techniques improve, with the James Webb Space Telescope, the Transiting Exoplanet Survey Satellite (TESS, the planned successor to Kepler) and Europe’s Exoplanet Characterisation Observatory (EChO) in prospect, as well as continuing improvements in adaptive optics applied to large ground-based telescopes.

The ideal tool would be something like Europe’s Darwin space interferometer, which would be capable of obtaining the spectra of Earthlike exoplanets. But Darwin is not currently under development. And, as Charles Cockell has pointed out, even if the spectra of gases associated on Earth with life (H2O, CO2, O3) are obtained, they would not definitively prove that life had to be present, nor would they tell us anything about the nature of that life if it existed. The spectrum of Earth must have appeared much the same over the past two billion years, through dramatically different epochs of its biological history.

The only way to be sure would be to send an interstellar probe that could make in-situ measurements. Crawford presented his shopping list for the instruments he would like to carry on that probe, with a whole array of orbiters, landers and atmospheric entry probes, arriving at a mass decelerated into the target system in the range of 150 to 200 tonnes.

Ian Crawford

Image: Ian Crawford discussing instrumentation for an interstellar probe.

But his reasons for interstellar exploration extend beyond science. He presented arguments from the seventeenth-century philosopher John Locke, who reasoned that the human imagination cannot produce anything genuinely new. In order to refresh both science and our broader culture, therefore, it is necessary to go out and physically discover genuinely new things. Interstellar exploration more than any other pursuit puts us on track to discover things that have never been thought of before.

Stephen Baxter, the well-known science fiction author and, like Crawford, an Icarus team member, discussed what might happen if one of our interstellar probes were to encounter intelligence at its destination. On the assumption that we had not known of the existence of intelligent life there when the probe was despatched, contact would take place when the vehicle was remote from any direct human control. How would it detect and recognise alien intelligence, and how might it be programmed to respond?

Stephen Baxter

Image: Stephen Baxter on probes and the potential for contact.

Of course, the extraterrestrials might see our vehicle arriving, and Baxter discussed ways in which this might come about. (Implausible, I thought: if they were that technically advanced, they would surely have visited us long before. The time window in which they are developed enough to detect, say, the exhaust from the fusion engine of a decelerating vehicle, and to recognise it for what it is, but not developed enough to be launching their own interstellar vehicles, would be only a few centuries at most in the history of a species whose origin is not coordinated with that of H. sapiens and might well be millions to billions of years earlier or later.)

These issues are presented in more detail in Baxter’s article in the Jan./Feb. 2013 issue of JBIS. He also noted that his own latest novel, Proxima, is, appropriately enough, an interstellar yarn.

The word from the A.R.

(I don’t know if people still call the Astronomer Royal “A.R.”, but I did re-read Fred Hoyle’s classic The Black Cloud not so long ago, and they certainly did then.)

Lord Martin Rees, the Astronomer Royal, has written extensively on the cosmos and the outlook for human civilisation. He brought an astronomer’s perspective on time to the Symposium, particularly future time: assuming we do not become extinct, post-human evolution will be much longer than that which led up to us, and will moreover be accelerated and directed in new ways by genetic and computer technologies. So far as our evolution is concerned, we have not yet reached even the halfway point.

What role, he asked, will humans play in space? In contrast with Ian Crawford’s well-known view, he did not see any case for astronauts as scientific explorers in an age of increasingly capable robots. But the human adventure of space travel in person was undeniable. He gave two pointers to the human future in space: China might leapfrog the US and send astronauts to Mars, and meanwhile the private sector was also on the verge of sending passengers into space. NASA had become risk-averse, creating an opportunity for privately funded adventurers who were willing to accept greater levels of risk – not as “space tourists”, for that phrase gives a misleading impression of safety and regularity, but as participants in a dangerous sport akin to deep ocean diving or making the ascent of Everest.

Rees at Podium

Image: The Astronomer Royal analyzes current space efforts.

(I would disagree with the A.R. on two points here. Having already experienced the disappointment of seeing Soviet cosmonauts fail to reach the Moon, I do not share the enthusiasm for Chinese manned spaceflight. They are currently about where the two traditional superpowers were before the Salyut 6 breakthrough in the late 1970s. I have heard no reason why a Chinese Apollo, Shuttle or continuously occupied Station programme, were such to appear, would be any more sustainable than their American and Russian originals, and they are nowhere near even beginning the major structural reorganisation currently underway across the Atlantic, essential for meaningful progress at this point. Meanwhile, although we do not yet have space tourism as such, the creation of a mass market for space travel at a level of at least 5,000 passengers/year worldwide (say, one planeload of 20 every weekday of the year) at near-airline standards of service seems to me to be vital for consolidating our hold on low Earth orbit, bringing the costs down and reliability up to levels that allow for sustained exploration beyond near-Earth space.)

Lord Rees stated, reasonably enough, that there would never be mass emigration from Earth, and so Earth’s problems would have to be solved on their own terms. But by the end of the current century there could well be small groups of pioneers living away from the mother planet. Interstellar travel, however, is for post-humans, whether genetically modified but still biological humans, or entirely manufactured beings.

He pointed out that explorers of our own planet were in some ways going into the unknown to a far greater extent than astronauts ever will. They were crossing oceans and continents about which nothing was known but much was imagined, completely out of touch with their port of origin, unlike any astronaut, whose journey takes them to lands already surveyed by telescope and probed by robot precursors, and in direct line of sight radio communication (if delayed by light travel time) with Earth. But what terrestrial explorers did have was a high expectation of profitable discoveries leading them ever onward.

As an astronomer, Lord Rees was naturally no stranger to the longest possible future perspectives, when the apparently accelerating cosmological expansion has carried almost all the universe beyond our horizon, leaving only the matter in the Local Group of galaxies accessible to our remote descendants. Maybe they would find that they were living in only one universe in a multiverse, or in someone else’s simulated universe.

General discussion

The presentations were followed by general discussion. There was some debate about the key factors in our intelligence, and in that of any intelligent alien species which we might meet elsewhere in the Galaxy. Biologist and science fiction author Paul McAuley pointed out that species other than ourselves use and make tools, and suggested that the key to our success had been our ability to archive knowledge for future generations to use.

Paul McAuley (2)

(My own view is that an archive, such as a library containing books, is itself a kind of tool, so that does not answer the question. My answer would be that we are unique in that we not only use and make tools, but that critically we use tools to make better tools. It is this recursive use of technology back onto itself in order to make better technology that is what drives progress.)

I should like to draw particular attention to what was said about the near-term future, before an interstellar mission is even launched. For it is what happens on Earth and in space over the next few years which will determine whether or not our civilisation even has an interstellar future.

Image: Science fiction writer Paul McAuley.

Ian Crawford made the point that the single most important factor was to reduce the cost of access from Earth’s surface to orbit, whether this was done with single-stage-to-orbit spaceplanes, or by construction of a space elevator. (Here let me link to the latest news on Britain’s Skylon spaceplane programme, managed by interstellar pioneer Alan Bond of Daedalus and worldships fame.)

James Benford argued for nuclear rockets, firstly fission engines of the type developed by NASA in the late 1960s, later fusion engines, which would open up the Solar System. SpaceX, he agreed, would surely succeed in lowering costs, but in his view there was also a case for beamed power for access to space. His brother cautioned that the laser-ignition fusion work in which he had been involved forty years previously had still not achieved a useful result, but that there were good prospects for fusion based on the proton-boron reaction. Stephen Baxter proposed that large-scale geoengineering projects, such as building a solar parasol to keep Earth cool, or the large-scale development of solar power satellites, might be an important driver of progress.

The debate over whether space agencies or the private sector are in the better position to lead produced a number of points. Governments are broke, James Benford said, hence the private sector must lead. Governments are risk-averse, Lord Rees added, leading to the same conclusion – new moves will be spearheaded by crazy billionaires, leading small groups of eccentric but highly motivated people. In his view, this would be no bad thing: we should encourage everyone to explore the limits of what humans can do.

But Gregory Benford (whose novel The Martian Race features the Chinese government competing, with European collaboration, in a race to Mars) allowed a possible leading role for government in the case of China.

Ashworth and McAuley 2

Image: The discussion continues. Stephen Ashworth (left) and Martyn Fogg.

Ian Crawford cautioned that space could not be allowed to become a free-for-all because of the dangers involved when, for example, asteroidal material impacts Earth. One could imagine a private group holding Earth to ransom in this way. It would therefore be necessary for us to evolve appropriate political institutions to ensure that space development is beneficial for all.

James Benford picked up this theme, stating that what governments can do is to make developments possible, or impossible. In the case of railways and canals they set up rights of way, for example by the purchase of land for the trans-continental railroad across the United States. Clearly, governments are also the guarantors of private property, and of the whole system of law and order on which economic prosperity depends. A creative synergy between government and private enterprise is therefore surely the way forward.

Next step: read the book!

In summary, then, this was a stimulating meeting with several of the key thinkers in the interstellar field. It was an excellent opportunity for people in Britain like myself who cannot hop across the Atlantic to attend interstellar conferences in the US, and it deserved to have been more fully attended (as it was, there were seats to spare in the smallish auditorium where the meeting took place).

The breadth and confidence of the vision of humanity’s and post-humanity’s interstellar future, presented in this and many other conferences, contrasts oddly with the current confusion and controversy about the direction of the public space programme in the United States, and with the apathy and stagnation in Europe. Clearly a major reorganisation of the space industry is under way, leading towards a more economically based industry in which government is one customer among many, as is already the case for Earth satellites but not yet the case for manned spaceflight, or for robotic ventures beyond geostationary orbit.

More details and discussion, from the speakers at this meeting and many others, may be found in the Starship Century book.

My thanks to the Benfords and to our hosts at the Royal Astronomical Society for organising this event.


Comments on this entry are closed.

  • Doug M. October 28, 2013, 9:48

    “An object flying at 3.75% of light speed possesses the same kinetic energy per kilogram of mass as that released in a thermonuclear explosion.”

    That’s very roughly true, but also somewhat misleading. A kilogram at .0375c has a kinetic energy of about 610 gigagjoules or 0.61 terajounles. That’s a bit less than 1/100 of the energy released at Hiroshima (67 terajoules). It’s also considerably less than the kinetic energy of the International Space Station (~13 terajoules). A Panamax freighter cruising with a standard load burns about 2.6 terajoules per day.

    Doug M.

  • Paul W October 28, 2013, 12:35

    I am glad there are some optimists out there.

    I was disappointed to read that the great Frank Drake believes, after a lifetime of work, that we are trapped on earth.
    He says that we will never be able to manage more than 30% of light speed, and if we did, hitting anything while going that fast would be like a nuclear blast.
    Interstellar flight remains a very problematic goal, even if it is an essential one!
    I would only say, hey, we don’t know the laws of physics yet, not really.
    Hopefully by the time we do, a fresh group of kids will be too intrigued to pay attention to what “is not possible”.

  • ljk October 28, 2013, 13:41

    Paul W October 28, 2013 at 12:35:

    “I was disappointed to read that the great Frank Drake believes, after a lifetime of work, that we are trapped on earth.
    He says that we will never be able to manage more than 30% of light speed, and if we did, hitting anything while going that fast would be like a nuclear blast.”

    Many of the SETI pioneers were not fond of interstellar travel. Certainly back in the day it seemed nearly impossible and also smacked of UFOs, which they were determined to avoid being associated with. If real starship ideas had to go down with the flying saucers, then so be it.

    These days professional SETI is often suffering from budget issues. Serious amateurs can do real Radio and Optical SETI with current technology, but only a relative handful seem to be dedicated to the task.

    As several people in the past have said on different issues, can’t we all just get along? There is room enough in this Universe for both methods.

  • ljk October 28, 2013, 13:43

    Starship troupers

    If starships are ever built, it will be in the far future. But that does not deter the intrepid band of scientists who are thinking about how to do it

    Oct 26th 2013

    SPACE, as Douglas Adams pointed out in “The Hitchhiker’s Guide to the Galaxy”, is big. Really big. It is so big, in fact, that even science fiction struggles to make sense of it. Most sci-fi waves away the problem of the colossal distances between stars by appealing to magic, in the form of some kind of faster-than-light hyperdrive, hoping readers will forgive the nonsense in favour of enjoying a good story.

    But there are scientists, engineers and science-fiction writers out there who like a challenge. On October 22nd a small but dedicated audience gathered at the Royal Astronomical Society (RAS) in London to hear some of them discuss the latest ideas about how interstellar travel might be made to work in the real world. The symposium was a follow-up to a larger shindig held earlier this year in San Diego.

    Starship research is enjoying something of a boom. “A few years ago, there was only one organisation in the world working on interstellar travel,” Jim Benford, a microwave physicist and former fusion researcher, told the conference. “Now there are five.” The following day many of the speakers at the event would visit the British Interplanetary Society (BIS, the venerable organisation of which Dr Benford spoke) to discuss design details for a starship named Icarus.

    Full article here:


  • ljk October 28, 2013, 13:48

    Starship enterprises

    Dismal scientists also like speculating about space flight

    Oct 26th 2013

    STARSHIPS (see article) are a fantastical subject. Yet when engineers design them, they try to be as rigorous as possible. After all, the laws of physics apply to a starship just as much as they apply to bridges or motorbikes.

    It is not just scientists who enjoy technically rigorous speculation, though. Economists have investigated interstellar travel as well. One of the best-known papers was written by Paul Krugman, a trade theorist, in 1978, in between his duties as an “oppressed assistant professor”. “The Theory of Interstellar Trade” describes itself as “a serious analysis of a ridiculous subject, which is of course the opposite of what is usual in economics”.

    Dr Krugman, a science-fiction fan, ponders how trade might work between two widely separated planets, Earth and Trantor. Such trade will be affected by relativity theory, which shows that beings on Earth (or Trantor) will see time pass at a different speed from those who are on board cargo ships moving between the two. This could make it hard to calculate the net present value of a shipment. And the fact that messages can move at best at the speed of light (and cargoes more slowly still) might do odd things to the ability to arbitrage between the economies of the two worlds.

    Full article here:


  • David Cummings October 28, 2013, 15:42

    Did Frank Drake really say “trapped on earth”. That’s extremely pessimistic. I can see how someone would say “trapped in the solar system”, but not “trapped on earth”.

    Maybe that’s what he meant. The solar system.

    The solar system is just a matter of time and money. We’re practically out there right now, just don’t have all our economic ducks in a row. Certainly we have the technology right now to have a major presence in the solar system, and even get people out there in the relative near term.

    He must have meant trapped in the solar system.

  • Wojciech J October 28, 2013, 16:05

    “The only way to be sure would be to send an interstellar probe that could make in-situ measurements. ”
    Disappointing. There are plenty realistic concepts of telescopes that would be able to take images of planets with their continents and potential changes in vegetation/planetary influence of life visible.

  • Wojciech J October 28, 2013, 16:08

    “I was disappointed to read that the great Frank Drake believes, after a lifetime of work, that we are trapped on earth.
    He says that we will never be able to manage more than 30% of light speed, and if we did, hitting anything while going that fast would be like a nuclear blast.”
    The part about 30% of light speed and enormous energies of collisions is close to the truth.
    We can reach speeds of 20% mostly safely in theory.
    That speed is sufficient to reach other stars.

  • Wojciech J October 28, 2013, 17:09

    ” It was an excellent opportunity for people in Britain like myself who cannot hop across the Atlantic to attend interstellar conferences in the US, and it deserved to have been more fully attended (as it was, there were seats to spare in the smallish auditorium where the meeting took place)”
    I was excited about the conference and wanted to go to meet the people there, who I respect, and who are inspiration. Unfortunately the conference was during working day, which made it impossible for me to attend, and which really depresses me, because I was really looking towards it.
    Making such event during the weekend(or at least part of it) would be much more sensible, and possibly would attract a bigger crowd.
    Nevertheless it made news in The Economist, which I hope will be a reason to repeat such meetings and conferences in future.

  • Astronist October 28, 2013, 21:07

    Doug M.: I find that a kilogram at a speed of 3.75% of c has a k.e. of 63,000 gigajoules (not sure why you get 610 GJ). This is equivalent to 15,000 tonnes of TNT (@ 4 GJ/tonne), so approximately the yield of a Hiroshima-sized weapon, which I believe is what Jim Benford intended.

    Stephen A.

  • Eniac October 28, 2013, 22:47


    My own view is that an archive, such as a library containing books, is itself a kind of tool, so that does not answer the question. My answer would be that we are unique in that we not only use and make tools, but that critically we use tools to make better tools.

    I think this is putting too much emphasis on tools. In my view, tools are merely a by-product of intelligence. An important one, no doubt, but intelligence certainly came first, and can in principle exist without tools.

    The principal difference between us and other (intelligent?) creatures is that we can exchange and accumulate information. Between ourselves, and, more importantly, to our descendants. What enables us to do so is language, plain and simple. Initially, there were no tools involved. Oral tradition alone gave our ancestors the ability to build culture, in limited ways. Later, writing greatly augmented this important ability and an explosion in cultural development followed. Tools and technology are a parallel development. Important, but merely a useful corollary of the ability to accumulate, process, and transfer information.

    The principal advantage provided by intelligence is not the idea to grab a bone and bash your enemy’s head in. This is important, but it is too narrow a view of intelligence. The real advantage is to outsmart the enemy, in a much more general sense. To cheat, trick, manipulate, rule. To be better at the chess game that is survival in a social environment. Even now in our highly technological world, the majority of intellectual endeavors are not technological in nature. Lawyers, politicians and merchants are still at the top of the “food chain”. Scientists and engineers are at least one layer down. For objective evidence of that look at salary, net worth, or influence associated with various professions.

  • Eniac October 28, 2013, 23:08

    One more: Nowadays the people who use their opposable thumbs for anything other than holding a phone tend to be near the very bottom of the totem pole.

  • NS October 29, 2013, 1:11

    “Governments are broke”

    Well, the ones that were foolish enough to give up their national currencies are (e.g. the EU) because they no have control over their money supply. The U.S. isn’t; it can create any amount of dollars at any time. It doesn’t, in part because its government is largely run by people who want to convince us that government is bad and can’t do anything right, and who try to prove it every day. Spaceflight is one of the smaller casualties of that effort.

    “Governments are risk-averse”

    If that was the case we’d all still be reading stories about spaceflight in paperback novels, instead of discussing actual spaceflights on the internet.

    “the private sector must lead”

    By and large the private sector is out to make a profit. The only profit anybody ever made in space came from government contracts. It’s likely to stay that way for the foreseeable future. Money (lots of it, spent with no expectation of near-term returns) is what we’ll need to get (further) into space. Government is the only entity that can provide the amount we’ll need. A few eccentric billionaires won’t be enough.

  • hungrytales October 29, 2013, 10:54

    @NS: So (some) governments can print money, therefore they cannot be broke – that is your argument? You, sir, win the award for the most ridiculous comment I have ever read on Centauri Dreams.

  • Alex Tolley October 29, 2013, 16:15

    @hungrytales. NS is correct. You have a economic model that states otherwise?

  • NS October 29, 2013, 23:22

    For a quick explanation of what ought to be well-known (but isn’t) see here:


  • Eniac October 30, 2013, 22:23

    … what ought to be well-known (but isn’t) …

    I think this is because it is easily recognized as nonsensical drivel by most.

  • G BENFORD October 31, 2013, 5:31

    So the Weimar Republic became rich and successful by printing marks? Consult other nations that right now have inflation measured in tens of percent. Nobody will deal with them.

  • Alex Tolley October 31, 2013, 10:52

    Well this didn’t take long to go OT and get close to invoking Godwin’s Law.

    @Greg – the Weimar Republic sustained hyperinflation because it did not get to pay its onerous WWI reparations in Marks, but rather in hard currency – gold. Had they been able to pay in Marks, the value of which they controlled, it would have been a different story.

    As long as a nation can issue debt (not print money) in its own currency, it cannot go bankrupt. Overzealous debt issuance, or currency devaluation via the printing presses may well cause severe economic disruption, but the state won’t become bankrupt simply because old debts denominated in the currency will be devalued.

    Zimbabwe is a case in point. It needed external foreign loans to finance its spending and stable currency to pay for imports in foreign currency. It couldn’t meet those payments and when it resorted to printing money, hyperinflation resulted.

    The US by contrast issues treasury debt in US dollars. As long as this debt is bought, both domestically and internationally, the US can go on issuing debt. There should be little doubt that the US can meet those debt obligations via taxation or public asset sales. But what if US cannot meet its debt obligations? The US can either deflate the value of the dollar or repudiate exiting debt. Dollar deflation allows deflation of previous debt and issue of new debt with higher interest rates offsetting expected future dollar devaluation (inflation). The US is therefore not bankrupt today, nor likely to be, which is in contrast to nations that must borrow funds in non-sovereign currency.

  • NS October 31, 2013, 12:45

    The Weimar Republic owed huge debts in foreign currencies and had major industrial problems. Its economy was limited by this.

    Most modern economies are not limited by lack of capacity (factories, labor, resources) but by lack of money in the hands of people who want to buy what the economies are able to produce. More money (driven ultimately by government spending) resolves that situation. Inflation will not be an issue until the economy is running at full capacity, which is far away in an economy like the U.S. (7 + % unemployment, many businesses crippled by lack of customers) and many others.

    Lots of things are “easily recognized” by people who don’t know what they’re talking about.

  • Astronist October 31, 2013, 12:56

    “Governments are risk-averse.” Note that a book on this subject, Safe Is Not An Option by the well-known commentator Rand Simberg, is due out any time now. As I understand it, the situation is that space agencies have been chastened by previous disasters and near-disasters into (a) attempting to design total safety into manned spacecraft, and (b) excluding private passengers. Both of these principles reduce the flight rate of any system, until we have something like the SLS which reportedly will only fly once every few years.

    Aerospace reality, however, is that a complex system cannot be perfected on the drawing-board, and needs to be flown frequently in order to iron out its inevitable teething problems. This is why commercial airliners undergo hundreds of test flights before they are certified fit to carry passengers, and why they have a good safety record thereafter. As we all know, the Shuttle was still uncovering serious problems on its 113th test flight, and therefore needed considerable further testing before it should have been declared operational.

    I am therefore inclined to agree with the A.R. on this point.

    Stephen A.

  • Astronist October 31, 2013, 13:40

    NS: “The only profit anybody ever made in space came from government contracts. It’s likely to stay that way for the foreseeable future.” I would be interested to hear your recommendations for overturning this sorry state of affairs and getting space companies such as Intelsat, Space Adventures, SpaceX and Virgin Galactic into non-subsidised profit. Without profitability in the service of mass markets, a space economy is hardly conceivable, and without that economy, ventures such as interstellar flight will surely remain dreams?

    Stephen A.

  • Astronist October 31, 2013, 13:50

    “Governments are broke” — I wonder whether I can resolve this debate by pointing out that, as I understood it, the point here is not a claim that they are economically bankrupt, but rather that the various pressures on their resources for more politically immediate goals (primarily defence, social security, and the attempt to control the world’s climate) are tending to crowd out spending on spaceflight. The reason for this is that the more immediate goals are perceived as core functions of the state, while space exploration is (rightly or wrongly) perceived as a luxury.

    The point which we should be focusing on is therefore whether the state can be induced to take on space exploration and colonisation as a core function of its raison d’etre, or whether on the other hand this process can be driven largely commercially with minimal technical and legal assistance from governmental space agencies.

    Stephen A.

  • Rob Henry October 31, 2013, 15:42

    Talking economic theory is generally non-productive due to trouble in testing various theories rigorously, but there is one major anomaly that seems most germane to the case. During WWII the US government went through a short period of high deficit spending with a specific goal in mind: to win the war. The strange thing was that when it came out of this period of what should have been non-productive spending, it was a superpower for the first time in its history, yet the entire economy seemed changed for the better. Virtually all measures of wealth, even meat consumption per head shot up from just prior to just after the war.

    My thought is: could a space challenge that engaged a nation induce a similar effect? Could it be a solution to national lethargy, and not the problem?

  • James Benford October 31, 2013, 16:15

    Stephen Ashworth: Your account of the London Symposium is a good job of showing the major points made.
    And you’re right about the energy of starflight: a 1 ton mass going at 3.75% of c has 63 TJ kinetic energy. A kiloton explosive energy is 4.2 TJ. So that 1 ton mass has 15 kiloton explosive energy (63 TJ[kton explosive/4.2 TJ]= 15 kton explosive). That’s the scale of the Hiroshima bomb.
    The point I’m making is that matter moving at such speed is as if the starship is a collection of H-bombs of the same mass.
    Indeed, Starship Century does count as the seventh interstellar group, having held events this year that had substantially larger attendance than all other groups: A total of 400-500 people have been at the five Starship Century events (La Jolla, San Diego, Pasadena, San Francisco, London) this year. What next? Getting the research started, of course. Greg and I are thinking over other possibilities.

    Jim Benford

  • Wojciech J October 31, 2013, 16:54

    “Lord Rees added, leading to the same conclusion – new moves will be spearheaded by crazy billionaires, leading small groups of eccentric but highly motivated people”
    There is an elephant in that room, which for obvious reasons is not likely to be discussed much.
    Religious groups and ideological movements would fill that criteria above quite well. There is no shortage of religious or ideological supporters with money.
    Some of the groups that could possibly be interested in such enterprises are Mormons, Quiverfull or Libertarian movement.
    The possibility of such groups engaging in off-world settlement shouldn’t be discounted.
    I wouldn’t mind. Whatever brings humanity out of its cradle is good in itself.

  • Alex Tolley October 31, 2013, 17:29

    @Astronist. Nice catch, sir. I like your reframing of the question, as both extremes, from “only governments can/should do space flight” to Musk groupies can find common ground there.

  • steven rappolee October 31, 2013, 17:42

    The EU or European union is one of humankind’s greatest inventions on a par with the USA constitution.
    regional governments such as this allow for the expense of war to be channeled from in future from NATO and WEU to perhaps the ESA!
    a common currency and a sense of a common citizenship lets the citizen at some point dream of all of us building some future great project of exploration.

    I suspect that the size of the world economy and the future state of technology might yield the following at around the same point in history;
    (A)(1) the ability to afford and build a fast probe/embryo ship
    (A)(2) at the same time in history this future world society will be able to launch a large slow world ship This society will not know for certain which one is the best option
    the costs of a fast ship will dictate that it is below .01 C and the risk averse humans will only risk the large population of a world ship on something that is .oo5 C It will have to be truly “airtight”

    only some fundamental nano probe will be able to beat this projection, but even here the results might not justify costs

    as for the size of detected planets I am still with Robin Canup’s calculations as to the mass of any gas giant exo moons and what would be the max size of any large neptunes exomoons? someone here a few months ago suggested impacts and capture as a alternatives
    these will be “rare earths”

    so lets do the Drake equation?

    percentage of neptunes & super earths in the habitable zone (we know from kepler!)
    percentage of the above with a collision or captured earth size exomoons in the habitable zone of,

    sun size stars

    red dwarfs

    A thought about red dwarfs? ( steven’s conjecture)

    lower orbital velocities in the habitable zone of neptunes and super earths or even earths in a red dwarf system might increase the chances of a impact evolved earth sized exomoons?

    Neptunes with the rare earth size exomoon would be free of intense magnetospheres?but prone to the angry red dwarf?

    so steve’s conjecture is this, yes the person who challenged me on here a while back is right! Robin Canup is right but some small subset of these exomoons will have been captured or as a result of impact
    (1)galaxy X stars X large earths and Neptunes
    (2)percentage with rare earth size exomoons
    (3) percentage of these in the habitable zone
    there is a paper that predicts earth moon systems……………………..

  • steven rappolee October 31, 2013, 18:04

    I ment mini neptunes in the post above

  • NS October 31, 2013, 23:53

    As far as being risk-averse, I think in the U.S. that NASA more or less boxed itself into that corner. During the Mercury/Gemini/Apollo years (which I am old enough to remember) astronauts were basically seen as test pilots flying in experimental vehicles. Events like the Apollo fire and Apollo 13 were traumatic but recognized as the kind of hazards that go with space flight. With the shuttle and ISS NASA promoted the idea that manned space flight had now become routine, which it isn’t and may never be. I agree that a return to the earlier attitude is essential.

    I didn’t mean to derail the thread with arguments about economics, but the blanket statement was made that “governments are broke”. I was trying to point out that some really are but others are acting like it when they don’t need to. Not being willing to pay for something isn’t the same as not being able to.

    I honestly don’t have any ideas for making space a paying proposition in the near future. I can’t see space tourism (i.e. the goal of most current private efforts) as ever being more than an expensive niche market. The only mass-market ideas seem to involve things like asteroid mining which I think most would agree are decades away at least. There are a lot of unprofitable hurdles to getting there. At least in our current economy governments are the only entities that can spend on that kind of time scale without the expectation of shorter-term economic returns.

  • Astronist November 1, 2013, 17:23

    NS, thank you. Yes, I could certainly have analysed the blanket statement “governments are broke” in a little more detail — I understood it as shorthand for the statement that they are under pressure, in which situation spaceflight gets short shrift.

    Obviously, a number of people have proposed that once space tourism is established as an expensive niche market, then a virtuous cycle of increasing market size and falling costs can come into existence, along the same lines as it did for air travel and for ocean cruising. In the UK, this view is promoted by David Ashford (of the company Bristol Spaceplanes), and by Professor Patrick Collins (a UK expat based in Japan). Several symposia in London in recent years have explored the possibility. As I said above, I believe this kind of economic expansion in space (which may take a century or so to mature) is essential in order for an interstellar-capable civilisation to evolve.

    Stephen A.

  • Eniac November 1, 2013, 23:59

    Alex Tolley:

    The US can either deflate the value of the dollar or repudiate exiting debt.

    The latter is called default, aka bankruptcy, and the former amounts to the same thing. The notion that printing money is a way to create wealth is entirely ridiculous.

    That said, I agree with you and NS that the US is nowhere near bankruptcy, and that deficit spending is not a bad thing in itself. As Astronist has touched on, the more important point here is that most of us feel that we need other things even more than space travel, as reflected by the much larger budgets for things like defense, soical security, and cancer research. You could argue that space is more important than any or some of these, but you’d have a hard time convincing enough people to make a difference.

  • Astronist November 2, 2013, 9:11

    Eniac: “tools are merely a by-product of intelligence. An important one, no doubt, but intelligence certainly came first, and can in principle exist without tools.”

    I would suggest that a tools are not merely a by-product, but that they actively augment intelligence, or perhaps I should say, develop a new kind of intelligence. They allow an economic surplus to be accumulated, creating both oppportunities and necessities for new kinds of problems to be tackled in, say, mathematics and politics, and they obviously vastly increase information retention and processing through libraries, calculators, computers, and scientific discoveries.

    I suggest that we should agree there are two kinds of intelligence: the fundamentally biological intelligence of a non-tool-making species, as opposed to the tool-augmented intelligence of a technological one. The first is restricted by the material limitations inherent in a non-technological lifestyle, while the second type of intelligence can be progressively augmented.

    A bio-intelligent species is not likely, I suggest, to have any opportunity to deal with problems in quantum mechanics, or planetary formation, or the organisation of global societies. Nor will they have library archives or computers to help them to to do so, in contrast with a techno-intelligent species. They may, however, still have a rich oral tradition.

    It is techno-intelligence which may be detectable at interstellar distances, while bio-intelligence cannot be detected unless by a probe which lands on the planet where it is found.

    Stephen A.

  • Alex Tolley November 2, 2013, 11:56

    The notion that printing money is a way to create wealth is entirely ridiculous.

    Somewhere the meme “avoid bankruptcy” has become conflated with “create wealth”. These are separate issues.

    Deflating currency values (e.g. via exchange rates) (and not necessarily printing money) can create wealth, as it improves terms of trade. During the depression, nations competitively devalued their currencies to try to improve their trade position. Obviously they cannot all do it at the same time. In a floating rate currency regime, countries are inflating/deflating their currencies all the time.

    During the current mini-depression/great recession, where interest rates are at the zero bound due to low aggregate demand, printing money to instill a worry of inflation will indeed create wealth as it puts savings back into circulation and increases aggregate demand. A special situation, certainly, and not to be indulged in excessively.

    If inflation is a monetary problem, as “monetarists” believe, we have had persistent inflation by over printing money since the 1930’s. Only the hard money advocates think this is a really bad effect.

  • Astronist November 2, 2013, 14:46

    As to the number of interstellar organisations currently active, Jim Benford’s list of six is conservative. Tau Zero list twelve, not including NHMI, of which eight were started within the last ten years.


    Stephen A.

  • Eniac November 3, 2013, 15:25

    Astronist: Good points. I certainly agree that technology enhances the effects of intelligence. I also think that technology is an inevitable consequence of intelligence. All I am trying to point out is the sequence: Technology has at most a minor role in the development of intelligence, while intelligence is an absolute requirement for the development of technology.

    Strong evidence for the former, for me, is that technology (or culture, for that matter) develop far too fast to have an evolutionary impact, whereas intelligence clearly requires the evolution of a suitable brain.

    In other words: Our brains now are just as capable as those of people before the advent of writing, so nothing as advanced as writing could have been involved in their formation.

  • ljk November 13, 2013, 11:11

    GEORGE DVORSKY FUTURISM 10/25/13 2:05pm

    Meet the people who want to build our first starship

    Recently, a group of scientists, engineers, and scifi writers gathered at the Royal Astronomical Society to discuss the latest ideas about how interstellar travel might actually happen. Here’s what they talked about.

    Full article here:


  • ljk November 17, 2013, 2:45

    NOVEMBER 15, 2013

    John Slough Personally Explains his Fusion Rocket and Fusion Energy Systems in Videos and Presentations

    John Slough gives a presentation of his direct fusion drive rocket and his fusion energy system.

    * they create ionized gases in two regions
    * they create plasmoids (balls out of the ionized gases)
    * they use magnets to accelerate and collide the gas
    * they implode a metal liner around the plasmoids
    * they accelerate the imploded liner and plasmoid out of spaceship for propulsion at the desired speed of the ship


  • ljk December 5, 2013, 0:03

    Going Interstellar

    When it comes to star travel, some people won’t take no for an answer.

    By Damond Benningfield

    Air & Space magazine, January 2014

    Like many boys growing up in 1950s England, Gerald Webb dreamed of the stars. He followed the exploits of the British Buck Rogers—Dan Dare, “pilot of the future”—and was thrilled by the launch of Sputnik in October 1957. Unlike most boys, Webb followed his dream. He joined the British Interplanetary Society at age 16, earned a degree in physics, and was helping to build payloads for sounding rockets when the society asked for volunteers for a new project: designing an interstellar probe. The team met every few weeks at a pub, The Rising Sun, and in 1978 produced the world’s first detailed plan for a starship: Daedalus, a 60,000-ton agglomeration of spheres, disks, and cones with an engine nozzle big enough to cover Trafalgar Square.

    After that, Webb lost touch with the stars for a while. He stayed in the space business, becoming an aerospace consultant and helping to start a company that brokered satellite launches on Russian boosters, but the scope of his work was limited to Earth orbit.

    On an unusually mild afternoon last August in Dallas, though, the stars once again feel within his grasp. Webb has joined about 200 other attendees at Starship Congress, a conference dedicated to promoting interstellar travel. The discussions range from solar sails to distributed databases, warp bubbles to game theory, exoplanets to international monetary policy. Session chairs periodically call on Webb, a sort of minor rock star among the interstellar crowd, for comments or to lead off the questioning.

    While the speakers in the hotel meeting room talk about future searches for extraterrestrial intelligence, Webb, taking a break from the presentations, sits just outside, fidgeting with piles of brochures on a display table. Starship posters line the wall behind him, while another table offers colorful postcards promoting “Sunny Gliese 581e: Only 22 Light Years.”

    “There hasn’t been a lot of progress in the field—all the problems we talked about are still being discussed,” Webb says. “I’m not disappointed in the lack of progress though. Things have started to get better—the necessary conditions for a starship are being laid. It’s reached the point where I think it’s inevitable. It will happen.”

    Full article:


  • ljk December 20, 2013, 9:47

    One step closer to a fusion power plant: