Re: ...Nasa/Griffin LYING about Public Support for Moon/Mars Missions!

On 5 Nov 2006 21:35:34 +0100, Jim Davis <jimdavis2@xxxxxxxxxxxxx> wrote:

John Schilling wrote:

That probably works in favor of the habitat, actually.
Photovoltaics are extremely expensive, pound for pound, and if
we go with the solar dynamic option instead, well,
turbomachinery and gossamer structures aren't cheap either.

Well, if we grant your assumption that SPS is delivering power at
current electrical rates you've also assumed that photovoltaics,
etc have gotten a lot cheaper.

Well, yes, but the "etc" includes all the other sorts of space
hardware, including habitats and OTVs. Again, as long as it
affects everything equally, the analysis holds. If you want
to argue that one sort of space hardware is going to be getting
cheaper, faster than all the others, that might shift the balance,
but I don't see any basis for that.


Most of the habitat mass, though, is relatively simple metal
structure or similarly tractable stuff.

Oh, sure. Just like ISS.

If you want to use ISS numbers for habitat mass, then for sake of
consistency you need to use ISS numbers for solar array mass.

That's going to make powersats absurdly, impractically expensive
across the board, obviously. But, still, slightly less absurdly
impractically expensive if you provide an on-site hab for the
workers. All else being equal.

If you're going to assume that in-space photovoltaics have somehow
become orders of magnitude cheaper but in-space habitats are stuck
at ISS prices, that's just silly.


There's more than construction workers needed on-site to build
an SPS. And in the company towns I am familiar with, more like
50% of the population either works for the company, provides a
service that the company would have to provide on-site even if
it were running a spartan oil-rig-type operation, or otherwise
brings in enough outside revenue to pay their way.

"Residents = workers", is an approximation of the same sort and
roughly the same magnitude as, "Cost of SPS electricity = Cost
of SPS hardware"; if we insist on the extra level of detail
across the board, those two will mostly cancel anyhow.

Nonsense. The population in space would have to increase
*dramatically* once the workers become permanent residents.

Why? Why does the population of a Solar Power Satellite company
town, have to increase any faster than the population of, say, an
oil-company town or a mining-company town?

It *could* increase dramtically, if hab space is cheap enough and/or
there are sufficiently profitable things for the newcomers to do.
But there's no reason it *has* to increase by more than a factor
of two or so.

Again, this isn't hypothetical. There really are company towns
established in otherwise-inhospitable regions to save the company
the trouble of rotating workers every few weeks, whose demographics
we can examine. And, in fact, I expect to be visiting one later
this week.


--
*John Schilling * "Anything worth doing, *
*Member:AIAA,NRA,ACLU,SAS,LP * is worth doing for money" *
*Chief Scientist & General Partner * -13th Rule of Acquisition *
*White Elephant Research, LLC * "There is no substitute *
*schillin@xxxxxxxxxxxxx * for success" *
*661-951-9107 or 661-275-6795 * -58th Rule of Acquisition *


--
*John Schilling * "Anything worth doing, *
*Member:AIAA,NRA,ACLU,SAS,LP * is worth doing for money" *
*Chief Scientist & General Partner * -13th Rule of Acquisition *
*White Elephant Research, LLC * "There is no substitute *
*schillin@xxxxxxxxxxxxx * for success" *
*661-951-9107 or 661-275-6795 * -58th Rule of Acquisition *

.

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