> > a geostationary orbit [...] could come in handy for Earth
> > communications services (since geostationary satellites seem
> > to already be popular)
> Some of these arguments seem a bit strained, especially the ones
> about providing communications services. That's like proposing to
> build an entire city in order to collect weather data from that
> spot. The job is much better done with a simple unmanned satellite.
This was no proposal to build an entire city simply in order to
provide communications services. The cities are proposed to be
economically diverse, with some millions of residents exploiting
some tens of thousands of economic niches. Besides that, unmanned
satellites don't seem to be doing their jobs very well.
http://www.google.com/search?q=wildblue+sucks
48,700 hits.
Why spend half a billion dollars launching Wildblue satellites
when Wildblue can simply rent time on superior hardware (with
superior transmitting power) built (from scratch) and installed
in situ at an orbiting city? Launches of dainty GEO
communications-satellites (and how many thousands of those would
there be otherwise, throughout the 21st century) might instantly
cease, since they might not be able to compete against megaton
hardware built in place.
> Also, you'll actually get better response time for teleworkers in
> LEO than in GEO.
Indeed. This is one of the problems with LEO -- lack of
distance-forced cultural diversity. For GEO, the round-trip ping
latency is at least .24 seconds. However, I imagine even this
large of a latency probably would not hamper most
telephone-conversations (though it might be a problem for
eye-contact telepresence). (Wildblue latency, from Earth1 to
Earth2 and back to Earth1, is at least .48 seconds -- which is why
some Earth-based teleworkers cannot use it.)
> a first model habitat would be [...] quite expensive.
What makes you say that? I have been estimating a shell cost
on the order of $1/sqft of commercially-viable floor-space.
Manhattan highrise construction starts in the low hundreds of
dollars per saleable/leasable sqft. (Yes, those are not Manhattan
*land* prices. Those are the sqft costs on each floor, extending
into the sky.) My estimate-spectrum for unit built-out costs is
very broad, but typical units in Spartan configuration might cost
around $30/sqft.
Now, why would the shell-only cost be important, you might ask?
Build the innards as your customers arrive.
> make a similar argument about the temperature in other areas,
> but it's not until you get near the Arctic (or Antarctic)
> Circle that controlling the day/night cycle becomes a
> compelling feature.
I was thinking that controlling the day/night cycle would be a
compelling feature anywhere. Some of the first places I was
thinking of putting the Stage-1 precursor cities were Manhattan,
London, Tokyo, Beijing, and Shanghai.
For Stage-2, the simulated-isolation stage, I was thinking of
the High Desert in Nevada. Maybe Colorado would be a better choice,
since it is closer to space.
> > a first model habitat would be [...] quite expensive.
>
> What makes you say that? I have been estimating a shell cost
> on the order of $1/sqft of commercially-viable floor-space.
>
I'd like to see your figures. That sounds too low to me.
> I was thinking that controlling the day/night cycle would be a
> compelling feature anywhere.
>
Why?
> For Stage-2, the simulated-isolation stage, I was thinking of
> the High Desert in Nevada. Maybe Colorado would be a better choice,
> since it is closer to space.
>
I happen to live in Colorado. Such a domed city would never catch on
here; we love our great outdoors too much (and both the weather and
the day/right cycle are mild).
- Joe
> Why spend half a billion dollars launching Wildblue satellites
> when Wildblue can simply rent time on superior hardware (with
> superior transmitting power) built (from scratch) and installed
> in situ at an orbiting city?
Earth has a very expansive industrial infrastructure that is amortized
across a huge volume of business. A chip fabrication plant costs a
couple billion dollars. Why would such a plant be built in orbit in
order to produce a few specialized chips for the "superior hardware"
you imagine would be built? How about all of the other infrastructure
that forms part of the industrial chain that produces parts for the
"superior hardware," where will the economic transactions come from so
that the capital structures can be amortized?
The Earth-bound economy is valued at about $45 trillion per year and
tht volume of commerce allows that amortization of quite a bit of
specialized equipment. The satellite manufacturing business is, what,
$1 billion per year. So, I don't understand how, in order to save
launch costs, it's worth establishing a sophisticated economic
infrastructure in orbit and still come out with cost savings. Please
explain.
> Why would such a plant be built in orbit in
> order to produce a few specialized chips for the "superior hardware"
> you imagine would be built? A valid point. In reality, Ithink the progression will be something like this. Right now we're at square zero, where every last single thing we use in space is boosted up from the surface of the Earth. Square one might represent using some lunar soil in a radiation shield for some humans orbiting above the Earth's magnetic field. The next step might be use of lunar-material-derived oxygen as the heavier part of both propellant and water. Then we start manufacturing large glass windows, and large steel and aluminum bulkheads from lunar material, along with I-beams and tension cables. Then we start making solar panels which use lunar material for around 99% of their mass. This is the era when SBSP really starts to take off. Now let's look at a sophisticated, pneumatically-driven industrial system working in some orbital factory. At this stage of the process, perhaps the large steel parts of this system are manufactured locally, with ET materials. But the computer which guides the system is still being bought from Earth. But the computer is only a smallfraction of the weight of the heavy steel parts, so this is still significant leveraging with ET materials. At a later stage, some of the components of the computer system are being made locally, but the computer chips are still being boosted up from Earth. Fortunately, their weight is trifling. Earth-lift costs, which once dominated over everything,are becoming a vanishing fraction of the total expense. Only at a much later stage might even the computer chips be manufactured in orbit from ET materials. But that will be the stage where we see two separate, independentbranches of human civilization: the Earth branch and the space branch. That time is a very long time off. But I think you can see how use of space materials can get us to significant leveraging even at the much earlier stages, by initially attacking the "big dumb stuff" i.e. things of large mass which require lower levels of processing and manufacturing.
Mike Combs
If i may add a few points that space manufacturing has over the earth.
*Microgravity of course.
*Any process using a very pure vacuum.
*Any process where a large amount of light from the sun and cooling to a few degrees above absolute zero would be useful.
I know everyone on this mailing list are familiar with what I'm saying. You know if LEO becomes inexpensive, say a mag-lev booster or space elevator, there would be a lot of brain storming to think up profitable uses of this environment.
One thing I would like to propose which I think no one has brought up.
Space is the perfect place to believe it or not build large fusion reactors.
Think about it, the biggest problem with any kind of plasma containment is the fact that the plasma can escape hit the wall of the container and bring in impurities which would stop the fusion process not to mention melt the container. If you built in space or the moon you wouldn't need any container and not have to worry about losing plasma. After close to 60 years of R&D in controlled hot fusion containment it may first happen in orbit.
BestRegards,
Pete
> Why would such a plant be built in orbit in
> order to produce a few specialized chips for the "superior hardware"
> you imagine would be built? A valid point. In reality, Ithink the progression will be something like this. Right now we're at square zero, where every last single thing we use in space is boosted up from the surface of the Earth. Square one might represent using some lunar soil in a radiation shield for some humans orbiting above the Earth's magnetic field. The next step might be use of lunar-material- derived oxygen as the heavier part of both propellant and water. Then we start manufacturing large glass windows, and large steel and aluminum bulkheads from lunar material, along with I-beams and tension cables. Then we start making solar panels which use lunar material for around 99% of their mass. This is the era when SBSP really starts to take off. Now let's look at a sophisticated, pneumatically- driven industrial system working in some orbital factory. At this stage of the process, perhaps the large steel parts of this system are manufactured locally, with ET materials. But the computer which guides the system is still being bought from Earth. But the computer is only a smallfraction of the weight of the heavy steel parts, so this is still significant leveraging with ET materials. At a later stage, some of the components of the computer system are being made locally, but the computer chips are still being boosted up from Earth. Fortunately, their weight is trifling. Earth-lift costs, which once dominated over everything,are becoming a vanishing fraction of the total expense. Only at a much later stage might even the computer chips be manufactured in orbit from ET materials. But that will be the stage where we see two separate, independentbranches of human civilization: the Earth branch and the space branch. That time is a very long time off. But I think you can see how use of space materials can get us to significant leveraging even at the much earlier stages, by initially attacking the "big dumb stuff" i.e. things of large mass which require lower levels of processing and manufacturing.
Regards, Mike Combs
I agree that things like chips might be the last thing to actually be
Made In Space. However, I can think of two things which could change
that.
any more about it.
2) If it should turn out that microgravity allows the building of a
better chip. If the high vacuum and temperature extremes pointed out
by Spacebear are also needed, so much the better. If this happens,
then chips *will* be made in space, perhaps even before large glass
and aluminum structures are. Not to supply the in-space market, but
to supply the Earthly.
Of course, as nice as this would be, we can't build plans around it
unless and until it happens.
> 2) If it should turn out that microgravity allows the building of a
> better chip. Bill Higgins wrote a song called "Home on Lagrange", sung to the tune of "Home on the Range".This wasstill back in the days of the initial enthusiasm over0-G materials processing. One of the verses went: Oh, I've been feeling quite blue, Since that crystal I grew, Got too big to get through the door, But from slices I've sold, Hewlett Packard, I'm told, Made a chip that was seven foot four. > Of course, as nice as this would be, we can't build plans around it
> unless and until it happens.
Quite so. It seems that much of the wind has gone out of the sails of the notion of materials processing in orbit. The argument has been made that most of the people proposing these notions had been aerospace people, not materials processing people. The materials people could figure out ways of doing things on Earth which might not have been quiteasgood, but wereorders of magnitudeless expense. I had pretty much given up any hope on materials processing in orbit. But I did hear one person say that even now that we've got this permanent space station available, materials scientists find that the process of getting experiments up on the station is simply too lengthy and protracted. They seemed to imply that ifanother setup could get experimentsflown more quickly and easily, with procedural modifications and refinements implemented quickly, there might be a lot more interest in this field. So who knows; some good may yet come out of this area if someone can become a better service provider than NASA.
Mike Combs