[extropy-chat] Moon news

[Damien Broderick]

----- Original Message -----
From: "David Lubkin" <extropy at unreasonable.com>
Sent: Friday, January 09, 2004 5:49 PM

> Thinking of nanotech, though, is far beyond any competency I'd expect from
> journalism.

That's true, sort of, but then I'm a journalist, sort of, and in 2001 I had
a long cataogue piece on Mars and beyond in a major exhibition of that name
which is still touring Australian museums. No impact on GWB, it's true, or
the American taxpayer, but it's an existence proof. :)

I'll paste in a sample below.

> But, if I were in the position of allocating investment dollars, I'd put
my
> space effort into bringing back a nickel-iron asteroid.
> Hundreds of millions of tons of metal and organics in a useful Up location
> is a major bootstrap for anything else you want to do in space, and I
think
> would have a lot of synergy with nanotech.

Indeed, but again a moderately mature molecular fabrication system might be
expected to round up, smelt and return to LEO (or wherever) all the asteroid
metals you could wish, without sending humans out to do it (and die or at
least damage themselves horribly).

Here's a chunk of my piece, which has now been read by many tens of
thousands of people. I've been describing a classic skyhook:

========

         A staggeringly expensive project, even using molecular
mechanosynthesis, it will pay for itself many times over by replacing
rockets with elevators driven by electricity powered by solar energy freely
available and abundant beyond our atmosphere. What is more, building
skyhooks is easier on the Moon and Mars, and eventually it will be possible
to use robot construction machines to spin the great cables for us with no
human supervision. Rather than expend decades on rocket flights to Mars, it
might turn out to be cheaper and quicker, in the long run, to invest in a
major research and development effort in industrial nanotechnology able to
fabricate skyhooks for interplanetary travel. That way we'd have the
benefits of nano for all manner of useful purposes, and an attaintable
highway to space in the bargain.
         What is more, the trouble--and the great delight--of making such
projections into expected future technologies is that once you introduce
such a novelty as nanotechnology, everything else is liable to change in
unexpected ways. If you have access to advanced nanofacture, you might wish
to build other things. I playfully called the space hook a Beanstalk, but in
the fairy story the giant's Beanstalk grew upward from the soil, it did not
hang down from the sky. Might we use molecular or other advanced methods to
grow a ladder or tower upward into the clouds and far, far beyond them?
         NASA scientists Dr Geoffrey Landis and Craig Cafarelli have done
the engineering calculations. It seems that an immensely tall tower could
indeed be built. The stresses in a diamond tower with its mighty footings
deep in rock would be compressive, squeezing downward, the contrary of that
outward tension tearing at a space thread. Small shifts in the crust would
put it at risk of toppling or buckling, so active computerised management
would be necessary to ensure stability. Further calculations show that a
blend of skyhook satellite and very tall tower might be the optimal mix,
using less materials and cheaper to build. But these same technologies have
suggested a quite different audacious scheme to Dr J. Storrs Hall, one of
the few people to have devoted a lot of disciplined effort to exploring the
prospects of nanotechnology. His notion is strange, but remarkably simple
and perhaps elegant in the way of the Eiffel Tower. He proposes a Launch
Pier a hundred kilometres tall, extending above all but the last of the
atmosphere, and three hundred long.
         It would resemble the world's largest trestle, built from slender
diamond-like towers marching beyond the horizon like impossibly tall spidery
radio transmitters. At their top, a colossal rail structure would lead to an
edge I can imagine base-jumpers lining up for months to jump off. The rails
would carry magnetically levitated spacecraft, accelerating them smoothly
for 80 seconds at a crushing but acceptable 10 gravities. Released at the
end of their 300 km run, spared the burden of carrying most of their own
propellent, spacecraft would head for orbit along computer-specified
trajectories, correcting their paths with exquisite changes of velocity from
their conventional rockets.
         From the ground, you would not be able to see the immense launch
platform lost in the haze of air far beneath it. Perhaps you would only see
a few of the great struts plunging upward into the blue. Sunlight,
effectively undiminished, would shine through the lacy thing upon crops.
There'd be no noise, except where great gantries and elevators carried their
loads into the skies, powered not by expensive rocket fuel but by cheap
electricity (which might well be generated from solar energy at the top of
the trestle). How much would such a marvel cost to build? Hall claims it
could be built today, using available technology and materials, although at
exorbitant expense. With moderately early nanotechnology to spin the half
million tonnes of struts, plus magnetic coils and electronics, that
impossible price might plunge to $500,000,000, or more conservatively $10
billion. By comparison, 300 kilometres of superhighway today costs at least
a billion dollars; building the Hubble Space Telescope, hoisting it into
orbit and then repairing it took $3.2 billion; the International Space
Station's bill will be more than $20 billion. The Apollo mission to the Moon
cost $24 billion in 1960 dollars.. but today its mighty Saturn launch
vehicles have been dismantled and even their engineering plans were
destroyed. Hall notes: `If an Apollo-style (and -cost) project could do for
diamond what the original one did for electronics, we could build the tower
in the next decade or so.' Operating costs could fall to $1 per kilogram
lifted into orbit. Today's costs using rockets are 10,000 times higher.
         In short, a major push in developing molecular nanotechnology could
pay off by reducing the cost of this dramatic launch platform into
space--and provide us with all the other benefits of matter compilers almost
as an incidental. Those benefits will probably include inexpensive consumer
goods, perhaps including foods, clothing, safe terrestrial transport,
shelter and computation. That implies a complete and perhaps catastrophic
shake-up in the global economy, as we shift from a world of scarcity to one
of plenty within a brief period of time. During such an upheaval, will
anyone be thinking seriously about exploring the Solar System and beyond?
Yes--because even with the new opportunities for intelligent recycling that
nanotechnology affords us, we'll want all the extra resources we can find.
And space--in the form of asteroids, but also moons and planets, will be an
abundant source of raw materials for a very long time, without the
disturbing moral costs that should have troubled our colonising ancestors.

         iii

Finding clever ways to lift cheaply into orbit is just the first step, but
it is a step that takes us a long way, for it has been said that low earth
orbit is `halfway to anywhere'. While that is true, it depends on how long
you are willing to spend getting anywhere. By rocket from Earth orbit, the
Moon is several days distant. Coasting most of the way, getting to Mars and
back takes many months. Can we speed up the trip? And is your journey really
necessary?
         Several ingenious methods have been explored for boosting crewed
spacecraft to the nearest planets and the asteroids. You can fire tremendous
laser beams at the frail extended butterfly wings of a light-jammer, pushing
it gentle but inexorable into the void on the pressure of light itself. That
sounds absurd, but a highly reflective aluminium skin on a light-sail just
four or five atoms thick and nearly 700 kilometres across can be driven by
sunlight alone to nearly one percent of the speed of light, the maximum
velocity in the universe. Actually we can do better than that. A battery of
powerful lasers, pumping their blazing beams through a lens 200 metres
across, could strike the light-jammer's sail with such force that it would
be accelerated in two months to 15 percvent of the speed of light.
Conditions on board would be comfortable, because the acceleration would be
nearly one g, the force we are used to on Earth from gravity. You do not
need to carry all that mass of proppellent with you, and at destination, the
craft can be slowed by a number of equally clever means not requiring
rockets. One such, suggested by Dr Robert Zubrin, is to deploy an equally
vast magnetic sail-field that presses against the `wind' of the
interplanetary magnetic medium that suffuses `empty' space.
         Do we need to make this trip through the horrors of space at all?
Might we find ways to avoid the perils of weightlessness (which destroys
bone and muscle), radiation storms from the Sun, dangerous micro-debris that
can damage a craft or its instruments? A favourite fancy, fuelled now for
three decades by Star Trek, is the transporter beam, or instant
teleportation from one place to another. Recently this notion has been given
some real scientific grounding with the discovery, in relativity theory,
that wormholes might be possible. These are links through higher-dimnsional
space, joining locations and even times far distant and in principle
permiting signals or even objects to pass through, apparently faster than
light. Of course the transition would not actually be faster than light,
since the distance travelled has been abbreviated. Alas, current thinking
argues against the likelihood that wormholes or hyperspace can really allow
us to teleport instantly to another world, or even from the surface to a
starship propelled by antimatter. One reason for thinking that this sad news
is right is the absence of aliens in the Solar Sysytem, let alone the earth.
If wormhole travel is easy and available, we'd expect the galaxy to be
swarming with star voyagers (assuming that life exists beyond our own
planet). That goes as well, admittedly, for near-light-speed star travel,
such as light-sails or antimatter-fuelled craft, but such vessels would take
years, centuries, even millennia to get to their destinations. That might
cramp the enthusiasm of many extraterrestrial species, encouraging them to
stay at home and sent small nano-robots exploring in their stead. Such
shrunken probes, containing miniaturised artificial intelligence systems
perhaps smarter than human brains, could be accelerated inexpensively from
their home worlds to nearly the speed of light, spin themselves sails from
the interstellar debris as they approach their destination, infest a
convenient asteroid or lifeless moon and start to replicate. A nano-seed of
this sort could build further probes to explore the new system, and enormous
radio or optical transmitters to pump back an encyclopaedia of new
information to the home world. True, the society that launched them
thousands of years earlier might by then be dead or transformed, but the
gale of knowledge would flow across the emptiness between the stars,
bringing riches beyond dream to anyone listening.