From: Robert J. Bradbury (bradbury@ilr.genebee.msu.su)
Date: Thu Nov 11 1999 - 08:47:00 MST
Obie Wan Burch asked an interesting question...
> How quickly after the development of a general purpose programmable
> assembler could a completely "de novo space program" be developed, and how
> many (or rather, how few) people with what expertise would be necessary
> to do it?
Depends on how much you can leverage it from previous work. The
actual construction of an alternate environment, could in theory
take relatively little time. The construction of large scale
habitats is limited by energy, element abundances & designs.
If you have the necessary element abundances you can get lots
of power in a couple of weeks. So then it comes down to designs.
The question of designs comes down to a question of how much mechanical
engineering (esp. of the nanoscale type) is "automated" by circa 2010.
What you need is "matter" description languages, compilers and verification
tools. These exist today for the electronics industry, but not for the
MEMS/nanotech industries.
If you had the tools, and you could piggy-back on top of the general
nanotech development on Earth, I think it could be fairly simple and
fast (certainly within the bounds of a few thousand dedicated people,
perhaps even a few hundred). One key element you would probably want
is a "Sport Utility Vehicle" air-car. Take your basic air-car design
and enhance it for space operations. Probably means that you have
to add a big pod on the back for fuel tanks & a rocket engine.
This gets "humans" off the planet.
Then you want a nanotech-based "mass-driver" design for hurling
"matter-pods" of essential elements from places where they are to
places where you need them. You probably want to make the pods
self-navigating.
> Thus, I imagine that the immediate goal is to establish a presence
> on Luna, where raw material would be most quickly available for further
> development. I know that it takes less delta-vee to utilize resources in
> the asteroid belt, but in this scenario, time is of the essence.
I have my doubts about this Greg. So you get to the moon quickly &
you have an assembler. You still don't have much of the essential
elements on which your earliest nanochemistry is likely to be based.
Virtually no C, and precious little H & N. You could take the Freitas
study on self-replicating factories and re-work it based on nanotech
on the moon, but as I recall that study required a lot of supplement
material from earth and that is probably something you would like
to avoid.
I'd argue, you want to jump directly from Earth to a NEAR asteroid,
preferably between the Earth & Venus. If you could get a carbonaceous
chondrite, that would be great. Hollow it out and build a city
out of it. I think the lower gravity wins big for interplanetary
transport. If you find an esteroid with some ice, great, otherwise
you want to find a nearby comet and send out a ship to haul back
a big chunk of it. The alternative would be to target a comet,
but these seem fairly loosely assembled and come apart upon heating.
You could also target an orbiting station above Venus since you can
harvest the carbon from the atmosphere (other materials become more
difficult and probably require very messy surface trips). I think
its important to go "inward" rather than "outward" since your
energy harvest per kg of material available is greater, so you can
construct things faster.
> So, what is the minimum set of basic skills and how quickly can the posited
> "small band of nanotech-enabled transhumanists" get off Earth?
You need computers & nanocompiler software packages and probably
a fair amount of mechanical engineering skill.
> Thus a basic rocket booster would have to be developed and proven
> with a minimum of tests and versions.
Hmmm... your mass requirements are going to be reduced the most if
you breath air as far as you can, then use rockets for the last
boost. Ideally, you launch your SUV-AC with your O2 tank empty and
fill it on the way up.
> This booster would ideally be [snip]
Why do you want "boosters"? Ion propulsion is much more efficient
(if you don't care how long it takes to get there). Mass Drivers
avoid the requirement of having to carry around a lot of "structured"
material that isn't of much use other than to speed you up & slow
you down. I think you want to make as fast a break with gravity
wells as you can. If it gets to the point where you have to
start hurling things at each other, the people sitting in the
gravity wells are at a distinct disadvantage (they pay a cost
hurling something at you, and you get some free "added energy"
when hurling something at them).
> <> Some kind of basic modular robotic spacecraft "bus" would have to be
> developed.
I think all you need is minimal matter-containers with attitude
control. It seems that you can get lots of energy "fast", so you
have a very different transport mechanism from what we normally
think of. For example if you are putting things into gravity wells,
you design "minimal splatter" receiving docks, where a long thin
pod comes in and "crashes" into the dock. You quickly close
the dock doors, have the heat exchangers harvest the kinetic energy
released and then send the nanobot material sorters out to collect
the material shipment. The nice thing about "artillery" shipments
is that you only pay the costs on one end and you can recover most
of the energy expended on the other if you are really clever.
If we thought about it a little more, I suspect we could build
mass un-drivers that slow the pods down and harvest the kinetic energy
very cleanly.
Two things to keep in mind -- Its only "people" that you have to
keep assembled and have to accelerate and decellerate slowly.
Matter, you accelerate & decellerate quickly and it doesn't much
matter whether or not it remains assembled. If you have the
infrastructure in place, reassembling it takes only a few hours.
> <> A lunar surface rover chassis for use of the robotic systems in
> preparing a lunar habitat
Don't need this on an asteroid, since you can jump anyplace you want
to go.
> <> A basic manned spacecraft that could serve as a transit vehicle to be
> boosted up from Earth surface to LEO
You want to leverage the air-car into this (because you are way ahead
on the design process.
> <> A basic "hab module" that can be boosted into LEO and made part of a
> translunar vehicle
No, throw up the mass and build it in space, no boosters required,
just matter pods. You want to figure out how to ship the matter
from the place where it is most abundant that has the greatest
energy cost/kg delivered (depends on energy availability and
gravity well depth). Of course if you want to build things very
fast you may make some sacrifices on this count.
> <> Modular, scalable life support systems - from spacesuit to "hab module"
> scale
<> (Maybe) a spacesuit.
Why not a "hab-suit" with very sophisticated exo-manipulation
capabilities? You could live in it for weeks or months while
you constructed larger habs? Enough solar power collection to
harvest a few hundred watts with complete nanotech recycling of
waste into water and food. A self-contained space habitat.
If you have lots of design capability available you may be able
to do the SUV-AC transforming into Hab-Suit trick.
> <> A plan for robotic prefabrication of a basic lunar initial habitat.
It seems you want a general purpose "fetch, carry & manipulate" robot
(with perhaps "dog" level intelligence).
> Assuming the basic technical capability of a fully programmable assembler
> (i.e. the ability to make diamonoid structures of arbitrary size and
> complexity and thence the ability to extract basic elementary chemicals
> pretty easily), how few aerospace professionals would need to be involved?
If you are assuming diamondoid, you do not want to go to the moon.
The moon requires a nanochemistry for the assembly of nanostructures
out of Al, Fe, Ti, Si & O feedstock. All you require for an
asteroid is probably some C & Si + trace element feedstock &
chemistry. Given current trends I suspect these will be the
most well developed when you need them.
You also probably want more basic mechanical engineers and chemists
than aerospace engineers I suspect. Most of what they do is figure
out how to construct things that are cheap and can survive in space.
(I'll probably get raked over the coals for that comment...)
However, when you can do "perfect" atomic assembly and are working
with diamondoid materials you have to shift things to a whole new
area. You have to deal with radiation damage to nanotech materials
(not a skill common among aerospace engineers), you may need to
deal with heat radiation problems (pick up a few infrared telescope
designers), you *will* need to focus on energy harvesting so you
can pull a few people from solar cell development teams.
> What if they brought with them to the task only the knowledge that was in
> their heads and publicly available information? Given state-of-the art CAD
> circa, say, 2015 (assuming no runaway singularity in the meantime - which I
> do), how quickly could this minimal group start throwing stuff into orbit?
Well, I suspect if you have something like an air-car, you
could do a back-yard retrofit very quickly. *You* could start
digging your mass driver hole in your back yard now by contacting
your local water or oil well company now (must be a few of those
down in Texas, eh Greg?). The teams that have assembled previous
(non-military) mass drivers have only been grad-student groups.
The trick will be power & non-interference as you start launching
high velocity projectiles. It might be better to buy a piece of
a mountain in a desert someplace.
The *real* question is what will "state-of-the-art" nano-CAD design
packages be like in 2010-2015? We will have the computer power but
nobody is working on these right now (to my knowledge). If you
are going to rely on two people (Josh and Ralph) to produce your
software & chemistry you are going to have a long wait. My read
of the Nanotech conference is that they are the only people working
on these problems.
> How quickly could they start remote fabrication of an initial lunar
> habitation?
I'd always prefer to send the robots there first to do all the dirty
work, but that depends on being able to program them to do the job
reliably and handle "special case" situations. I doubt our current
state of software engineering is up to that. In 10 years, who knows?
> When could the first people get securely off Earth with a
> reasonable safety margin and a reasonable chance of maintaining their
> presence off Earth indefinitely? I assume 1) that very simple designs might
> be possible and 2) a secure launch site would be available - but one that
> might not be secure for very long once hardware starts going up.
If you have access to good software & the assembler, complex designs
are probably as simple as simple designs. Launching is a separate
and interesting question. Thats why a public-domain air-car to space
vehicle conversion design/kit seems to make sense. If everyone can
have one, I see it as harder for a government to suppress it.
Regarding mass launchers, you might need stealth designs. E.g.,
remotely piloted sub-components that can fly below radar level
to a specified location, harvest the power, construct a pod,
disassemble and move to another location.
However, it seems to me that if we are in an environment with
nanotech enabled "ubiquitous" surveillance, all of this might
well be impossible.
> This thought problem is thrown out with the intention of seeing just how
> difficult the "I'm clearing out as fast as I can after the assembler
> breakthrough" scenario really is.
In my mind, the big problem is whether or not you will have access
to the assembler... If we know it is possible (i.e. Zyvex has one)
but there are no nanotech designs to build anything with it
(e.g. ubiquitous nanosurveillance devices), then there may be
an opportunity to put together underground groups that build their
own before governments try to regulate everything. Of course you
are going to have to be clever about it because you can be pretty
sure if you bought an AFM in the last 2-3 years, the government agents
might well pay you a visit to see what you are doing with it.
The interesting thing about the U.S. and/or other countries is that I
suspect a lot of civil rights are going to get thrown out the window
in the name of national security once people *really* realize what is
possible.
A more interesting question in my mind, is whether the non-nanotech
space technology will exist circa 2010-2015 to get a group of
pioneers (backed by Swiss bankers) off the planet to allow the
development of nanotech unencumbered by government police states.
In this situation, many of the points made by Greg regarding a
re-hash of previous lunar development plans might be quite valid.
It goes without saying that if one is serious about these possible
problems that these are things that should not be discussed in
a public formum such as this. Whether or not the encryption &
communications software exists today to take the discussion offline
and keep it secure for the next 5-10 years, *is* something I'd
like to hear comments on.
While the light bulbs haven't gone on yet for people who would
be interested in this discussion, you can rest assured that someday
they will.
Robert
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