Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V16_4/V16NO402.TXT

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Date: Fri,  2 Apr 93 05:12:44
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V16 #402
To: Space Digest Readers
Precedence: bulk


Space Digest                Fri,  2 Apr 93       Volume 16 : Issue 402

Today's Topics:
                   Abyss: breathing fluids (2 msgs)
                     John Pike on SSRT prospects
                        Market or gov failures
                        Mexican Space Program?
                                NORAD
                        nuclear waste (3 msgs)
                    Pres. Clinton's E-mail Address
                         Quaint US Archaisms
                        STS-1 DISASTER/COVERUP
           the call to space (was Re: Clueless Szaboisms )
            Timid Terraformers (was Re: How to cool Venus)
                         Why is Venus so bad?
                  Why use AC at 20kHz for SSF Power?

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----------------------------------------------------------------------

Date: Thu, 1 Apr 93 02:39:34 GMT
From: [e-mail]
Subject: Abyss: breathing fluids
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Ed McCreary) writes:
>
>Until recently, the FDA has not approved the flourocarbon emulsion used
>in _The Abyss_ for use in humans, so little work has been done.  The
>liquid used in the rat scene was an electonic parts cleaner developed
>by 3M and yes, the rat really was breathing it and yes he lived a
>normal life afterwards.
>
>But, I've heard reports that's a similar emulsion has been approved for
>use in neonates who are experiencing lung problems due to underdeveloped
>lungs.  I've not seen the papers myself, but I have no reason to doubt it.
>
>--
>Ed McCreary                                               ,__o
>[e-mail]                                   _-\_<,
>"If it were not for laughter, there would be no Tao."  (*)/'(*)

Also work is being done using the flourocarbon emulsion as an artificial
blood because of it's great oxygen carrying capacity.

I worked in the lab of the scientist that first dunked the mice in the
emulsion.  He said that the largest animal that had done the liquid breathing
was a dog.  No one had really tried it on a human.  After seeing how the mice
reacted after breathing it, I don't think I would try it.

The Scientist was your typical mad scientist sterotype.  We even tried to
get ciccadas (locust type insect) to breath the emulsion.  It didn't work.


Tim Stroup
Lockheed Missiles & Space Co.
Sunnyvale, CA
[e-mail]

------------------------------

Date: Thu, 1 Apr 93 02:44:38 GMT
From: [e-mail]
Subject: Abyss: breathing fluids
Newsgroups: sci.space

In article <1pcjmt$[e-mail]>, [e-mail] (Pat) writes:
>In article <[e-mail]> [e-mail] (Ed McCreary) writes:
>|
>|Until recently, the FDA has not approved the flourocarbon emulsion used
>                        ^^^^^^^^^^
>|in _The Abyss_ for use in humans, so little work has been done.  The
>|liquid used in the rat scene was an electonic parts cleaner developed
>                    ^^^^^^^^^^^^^^^^^^^

>>>>   Deleted stuff          <<<<<<<<<<<<<<

>
>Of course, by the Time the FDA approves it for wide spread use,
>the EPA will have finished Banning CFC's, so it will be back to
>the drawing board.  Of course, it may make a pretty good non-dairy
>dessert topping.
>
>pat

Sorry Pat there are no C's in this flourcarbon emulsion.  That's why it
can be used in animals and humans.  But you are probably right that the
EPA will still ban it.  And it does make a good non-dairy >>dessert<<. :-)

Tim Stroup
Lockheed Missiles & Space Co.
Sunnyvale CA
[e-mail]

------------------------------

Date: 1 Apr 93 02:57:38 GMT
From: William Reiken <[e-mail]>
Subject: John Pike on SSRT prospects
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Allen W. Sherzer) writes:
>
> I hope your not giving up! Clinton and Pike don't have the final say. We
> can get it built if we are willing to push for it.
>
    Nice try. But Clinton and Pike are not your only enemies.  Your biggest
enemies are the lobbyist.  They have millions of dollars at stake and they are
not going to let you ruin there chance for a big payoff if they can help it.
The president and vice-president are only thier crownies to take the fall if
anything goes wrong.  They have no real power.

                            Will...

------------------------------

Date: Thu, 01 Apr 93 11:21:02 EST
From: Tom <[e-mail]>
Subject: Market or gov failures

[Fred saying that gov coercive poser is necessary for any space program]

I reply;
>>BTW, Fred, you've really crossed the border, since you admit that the ideas
>>you support can only be carried out with coercive power.  Now that's really
>>f***in' intolerant, so get off yer high horse about tolerance.

Fred replies;
>No, Tommy, I "admit" that there are such things as 'market failures'
>which necessitate intervention by other than capitalist forces to
>correct.

I guess your understanding of this 'market failure' should be classified
under Phil's 'economics on the level of 19th century medicine', since you
apparently completely ignored that this 'market failure' can as easily,
or even much more easily, be attributed to "government intervention
failure".  So, in addition to a strong moral argument against what you
propose, there is also a strong utilitarian argument, namely that gov's
destruction of wealth through confiscastory taxation and redistribution
on a major scale has made significant private capital investments harder
to make.

>Get a clue, little boy, and go salve your wounded pride in my not
>considering you infallible in some other fashion.  I'm not interested
>in your ego games.

Puh-leese, Fred.  This, besides being simply an attempt to be insulting,
really belongs on private mail.  If 'ego-games' are so unimportatnt to
you, why the insults and this strange negative attatchment for me?

-Tommy Mac
-------------------------------------------------------------------------
Tom McWilliams | 517-355-2178 (work) \\     Inhale to the Chief!
[e-mail]  | 336-9591 (hm)\\  Zonker Harris in 1996!
-------------------------------------------------------------------------

------------------------------

Date: 1 Apr 93 08:30:37 GMT
From: Nick Szabo <[e-mail]>
Subject: Mexican Space Program?
Newsgroups: sci.space

[e-mail] (Henry Spencer) writes:

>Canada's space budget is tiny
>compared to the US's, and Mexico's has got to be smaller yet.

Good grief, this is hardly the whole story.  Mexico has a huge,
young, mechanically skilled and literate workforce that,
like Russians and unlike American government contractors, don't
demand huge sums to do straightforward but tedious industrial
jobs.  U.S. and Japanese electronics firms already poor $billions
per year into Latin America.  Freed from defense & NASA
protectionist contracting rules (hah!  that'll be the day!) the
U.S. aerospace industry would likely do the same.

It is so habitual to assume that everything about the space program
must be lobbied for or dictated by some politicians.  If we want
to get beyond the current squabbling, we'd better break that habit.
The free market as vastly better at international cooperation than
any nationalist bureacracy.  If the U.S. government allowed it,
there would be huge cooperation with Latin America all across the
aerospace business.


--
Nick Szabo                     [e-mail]

------------------------------

Date: Thu, 1 Apr 1993 03:02:30 GMT
From: [e-mail]
Subject: NORAD
Newsgroups: sci.astro,sci.space

Does anyone have a telephone no. for NORAD? (Is it called Space
Command now?). I need to urgently check if there have been any
re-entries in last 2 days! Any e-mail addresses would also be
of use!

------------------------------

Date: 1 Apr 93 05:21:52 GMT
From: Gary Coffman <ke4zv!gary>
Subject: nuclear waste
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (fred j mccall 575-3539) writes:
>In <[e-mail]> [e-mail] (Phil G. Fraering) writes:
>
>>Will, it's been illegal since the '70's to reprocess/recycle nuclear
>>fuel in the US. You can't remove the fission fragments from the fuel
>>rods, so that they have to be thrown into a waste storage facility
>>while they're still 98% good. This way, there's a major waste problem,
>>that you can use as an excuse to shut the whole industry down.
>>(I mean, what sort of place is the US if it requires by law that
>>90+% of usable uranium be thrown away, and then declare that there
>>is no legal place to throw it away, and finally state that until there
>>is, no more nuclear plants!)
>
>Just a bit off, Phil.  We don't reprocess nuclear fuel because what
>you get from the reprocessing plant is bomb-grade plutonium.  It is
>also cheaper, given current prices of things, to simply fabricate new
>fuel rods rather than reprocess the old ones, creating potentially
>dangerous materials (from a national security point of view) and then
>fabricate that back into fuel rods.

You don't get "bomb grade" plutonium in this type of reprocessing.
You need a starter material that comes from a short cycled production
reactor, otherwise there's too much Pu240 in the product that you can't
easily separate out. You also don't reprocess to "pure" plutonium, you
just enrich enough to make it viable reactor fuel again, say 5%. To
get to bomb grade, you "only" need to chemically process the fuel
elements, but that's a very nasty and difficult process. In the end
you still have too much Pu240 unless you use mass spectrograph separation
processes. It isn't quite Manhattan Project in complexity and expense,
but it's close enough that only a determined country is going to be able
to do it. If they're that determined, they can make bombs the old fashioned
way.

Gary

--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | uunet!rsiatl!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | emory!kd4nc!ke4zv!gary
Lawrenceville, GA 30244     |                     |

------------------------------

Date: 1 Apr 93 08:19:20 GMT
From: "Kevin W. Plaxco" <[e-mail]>
Subject: nuclear waste
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Phil G. Fraering) writes:
>[e-mail] (William Reiken) writes:
>
>>    A Question:  Has oil been found anywhere eles in our Solar System
>>        in the raw form that we dig it up in here on earth?
>
>I think something shale-like has been found.
>

1) Liquid water is required for the formation of shale.  This
has never been proven to have existed anywhere but on the earth.

2) Oil, as such, is composed of the chemically reduced remains
of living organisms.  These (previously living organisms) have
never been found anywhere but on the earth.

I suppose one could claim evidence for liquid H2O to have once
existed on Mars, and perhaps inside of Europa, but even that is
a Hell of a long way from demonstrating the existance of shale.
And, I suppose, one could call the red-brown goo that covers comets,
Pluto, and, no doubt, the surface of Titan "oil", but I wouldn't.

-Kevin

------------------------------

Date: 1 Apr 93 02:38:45 GMT
From: William Reiken <[e-mail]>
Subject: nuclear waste
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Phil G. Fraering) writes:
>
> Uh, maybe in Japan this would be feasible. You could buy the particle
> accelerators from us, and the accelerator guys would have something to
> do;
>
    Yes I see, except that I am American.  So I don't need to buy it.
I don't think the Japanese do either.  The companies working on SDI probably
where already bought out or are selling them the plans.  For example, the
company that developed and built the Patriot missles has already transfered
all the technology to a Japanese company here.  The Japanese don't need to
buy them now, they build them themselves.  So the accelerators really don't
need to be bought from the US.  Is not worth it.  They will just buy the
company.  Much cheaper, because you get all the knowledge and experience
transfered to Japan.

    Also, I was refering to a US idea.  I think I came from Los Alamos.
Yea, I knew about the laws as well.

                            Will...

------------------------------

Date: 31 Mar 93 00:31:04 GMT
From: Tom Damm <[e-mail]>
Subject: Pres. Clinton's E-mail Address
Newsgroups: sci.space

The e-mail address I have is:

    [e-mail]

Dunno if it works, haven't tried.


--
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
The brain is a wonderful organ.  It starts working the moment you
get up in the morning, and does not stop until you get into the
office.                                      -- Robert Frost

------------------------------

Date: Thu, 1 Apr 1993 15:46:05 GMT
From: Nick Haines <[e-mail]>
Subject: Quaint US Archaisms
Newsgroups: sci.space

In article <[e-mail]> [e-mail] ("F.Baube[tm]") writes:

   Ever seen a European map ?  There's no scale line

       |=====|-----|-----|-----|
       0     10    20    30    40  mi

   It's not necessary.  If the map is 1:200000, 1 centimeter is 2 kilometers.

Actually most European maps have a scale line, for innumerates.

   The solar system at 1:100,000,000 ?  No problem !

Hmm; you wouldn't get much of the system on without a _really_ big
map. Try 1:5,000,000,000,000 if you want it a useful size.

   Of course, pervasive innumeracy might make this impossible in the US.

Well, it seems several branches of US government are pressing for
metrication: visit a National Park lately?

Nick Haines [e-mail]

------------------------------

Date: 1 Apr 93 02:08:38 GMT
From: William Reiken <[e-mail]>
Subject: STS-1 DISASTER/COVERUP
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Matthew Kaiser) writes:
>
> he's wasting valuable diskspace and
> his gases are aggravating the greenhouse effect!!
>

    Oh, I don't know about that.  I don't get much time to read scifi
these days.  I just too bad that we don't have sci.space.scifi or something
like that to give people a place to put their short stories.  He only posts
about once a month anyway.  Besides, it is a free world and he is posting
his point of view.  So, you do have to respect that, whether you agree with
it or not.  After all maybe he dos'nt agree with your or my point of views.

    I suppose that if everyone was thrown off the net because someone did'nt
agree with him/her then there would'nt be anyone on it in the end.


                        Will...

------------------------------

Date: 1 Apr 93 05:10:48 GMT
From: Gary Coffman <ke4zv!gary>
Subject: the call to space (was Re: Clueless Szaboisms )
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (fred j mccall 575-3539) writes:
>In <[e-mail]> [e-mail] (Henry Spencer) writes:
>
>>In article <1p5rar$[e-mail]> [e-mail] (Pat) writes:
>>>Also, given that japan has no indigenous sources of radioactives,
>>>what is the economic difference for japan to import oil,  versus
>>>radioactives,  of which only a few countries produce...
>
>>Vulnerability of the supply line.  Japan could easily stockpile 50 years'
>>supply of slightly-enriched uranium (which is not useful for bombs, so
>>acquiring it shouldn't be a major hassle).  This is most impractical for
>>oil; on a clear day, the captain of a supertanker on the Kuwait-Japan run
>>can see the funnel smoke from the supertankers ahead of and behind him.
>
>Unfortunately, that is not what the Japanese are planning to do.
>Their plan is to stockpile some 30 *tons* of plutonium -- potentially
>weapons material, unlike reactor-grade uranium.  I believe the first 3
>tons (?) of reprocessed material under this plan were just recently
>shipped from France to Japan (accompanied by much ballyhoo from the
>anti-nuclear folks).

Actually, the key word is "reprocessed". This is plutonium from power
reactor fuel elements. It is heavily contaminated with Pu240 which
has a nasty tendency to be a sporadic neutron emitter, IE make a bomb
with it and it'll squib in your face likely as not. The reprocessed
fuel elements are not *pure* plutonium anyway. A lot more reprocessing
would be required to get it up to bomb grade. Remember that they're
going to burn this stuff in a PWR, and those don't like bomb grade
fuel at all.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | uunet!rsiatl!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | emory!kd4nc!ke4zv!gary
Lawrenceville, GA 30244     |                     |

------------------------------

Date: 1 Apr 93 04:59:47 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Timid Terraformers (was Re: How to cool Venus)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Charles Lindsey) writes:
>There is a rather basic (pun noted) matter of chemistry that has not
>yet been addressed in these discussions. The atmosphere of Venus is
>very acidic (carbonic acid and sulphuric/sulphurous acid, or CO2 and
>SO2 if you leave the water out). After terraforming you need a more or
>less neutral atmosphere if humans are to breathe it.
>
>To get rid of acids you need bases (i.e. metallic oxides) to combine
>with the acids.  Now is there any reason to suppose that the rocks on
>the ground will be basic? Or, put it anpother way given that all the
>acid presumably came out of the ground in the first place, is there
>some fundamental law of nature which says that, in a brand new planet,
>the acids and bases should just about cancel each other out. It is so
>now on the surface of the earth, but is that just a fluke?
>
>And even if the primordial Venus was neutral, how will the removal of a
>lot of hydrogen have affected the balance in the meantime?

Naively I think you've answered your own question. Acids require the
hydrogen in aqueous solutions to be reactive. With most of the original
planetary water dissociated, and the hydrogen gone, the pH of the
planet as a whole should tend toward the base side if it were neutral
to begin with. Now I don't know of any reason why we have to accept
that as a given based on a sample of one, but if it's true, adding
water to Venus should ultimately result in a nearly neutral atmosphere
and surface.

Gary

--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | uunet!rsiatl!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | emory!kd4nc!ke4zv!gary
Lawrenceville, GA 30244     |                     |

------------------------------

Date: 1 Apr 93 02:18:39 GMT
From: "David (Duis" <[e-mail]>
Subject: Why is Venus so bad?
Newsgroups: sci.space,rec.scuba

In article <[e-mail]> [e-mail] writes:
>In article <[e-mail]>, [e-mail] (David (Duis) Story) writes:
>
>>The latest world record was a dive to ~1100m done by a French
>>commercial diving company.  This was reported in the latest UHMS
>>Pressure.
>
>Can you post more information?  They probably had to do some very perverse
>things to keep people alive.

There really wasn't any more information, it was just a news blurb.

If you're interested in the topic of deeeeeep diving, I recommend _The
Physiology and Medicine of Diving_, by Bennett and Elliott, available
from DAN or your local library (maybe).  Lots of neat stuff --
including very accurate details on WHY they happen -- about HPNS, N2
narcosis, how to choose gases for different depths, etc..

Cheers,

Dave Duis                        NAUI AI Z9588, PADI DM 43922, EMT
[e-mail]                       See it, don't spear it.

------------------------------

Date: Wed, 31 Mar 1993 20:14:53 GMT
From: fred j mccall 575-3539 <[e-mail]>
Subject: Why use AC at 20kHz for SSF Power?
Newsgroups: sci.space

In <1p0dos$[e-mail]> [e-mail] (Pat) writes:

>In article <[e-mail]> [e-mail] (fred j mccall 575-3539) writes:
>>In <[e-mail]> [e-mail] (Pat) writes:
>>>rather then Fred McCall venting his spleen,  a much higher level
>|what you most deserve.  Go ahead, Pat.  Try posting like an adult for
>|a while without all the ad hominem attacks on people and insulting
>|

>Well, Gee Fred.  At that point, I had waited something around
>2 weeks for someone from a NASA or SSF contractor site to
>pick up a defense.  McKissock had popped up, thrown a few
>vague terms around and then dissappeared.  I had wanted
>to see something a little more solid, and he seemed
>to be hiding from the debate.  You may want to defend
>your Namesake station,  but I wasn't interested in your
>speculation.  I wanted to hear something from someone
>who actually works there.  Your insinuations that i was
>making up allegations,  didn't help the level of
>discourse.

Neither did your making up allegations.  Frankly, were I 'McKissock' I
would have told you to go do something anatomically unlikely with your
wants, after your approach to things.  When you are *asking* someone
to take the time out of their busy day (some of us *do* have to work
sometimes, you know, and have better things to do than cater to Pat's
random wants), blowing flame at them is probably counter-productive.
So you figure insult and diatribe are the way to elicit a good,
high-level discourse?  Welcome to the Nick Szabo school of policy
debate, Pat.

>|
>|No, the paperwork was *not* good because the requirements were bad.
>|

>Of course, people were so busy working on the paperwork,
>no-one ever bothered to see if the requirements were any good.
>Were asses kicked for this?  were people taken to task for missing
>something as simple as a requiremnt for a testbed?

Pat, get out of management and outside the Beltway and learn something
about the real world.  Then come talk to me.

>No, Probably not,  but if these two centers can't co-ordinate
>enough to make a simple test bed and test article conform,
>what makes you Fred McCall, think that they will get it together
>for one of the largest integration efforts in engineering
>history?

What made you think that I thought they would?  I certainly never said
that.  Pat, if you can't pull your head out and hold a rational
discussion, why don't you just go and shout in a mirror?

>|>Ah,  the but the paperwork was good, the requirements document
>|>had been flowed down into each sub-contract and a full tracability
>|>matrix had been done.   How could it not work.
>|
>|Bad requirements.  Do you know *anything* about engineering, Pat?
>|

>Usually the lead requirement is that the system work.  Do you know
>anything about making Products?

Pat, go get yourself a clue.  Then find out something about system
engineering and requirements analysis.  Obviously you think you're the
only person who knows anything on the planet; I'm just wondering which
planet that is.  And of course I know nothing about making Products.
I don't do lame capitlized words like Products and Engineers.  Now, if
you mean do I know anything about making products, what do you think
we do here at TI; print money in the back rooms?  What a stupid git!

>|>How did skylab cope with the DC problems?  Skylab was
>|>fairly big,  it had several arrays,  and various power demands.
>|>Anyone have the historical background?
>|
>|Skylab was small and underpowered compared to what SSF was supposed to
>|be.
>|

>Skylab also Flew.  Which SSF,  looks unlikely to do at any time
>this century,  unless serious changes occur.  The Tiger Team
>review,  now has it Down  to Space Station F.

Which proves that if you hack away at something long enought it
eventually goes away.  BIG surprise, Pat.  Do you have a point, or
just more random flamage?

>|>Also, despite what GD may say about DC power complexity,  Somehow
>|>it does seem to power a large fraction of our industrial equipment,
>|>every vehicle in america,  and numerous LARGE transportation
>|>systems.   I would guess that the complexity of the power
>|>system of METRO is at least as large as that of SSF.
>|
>|Gee, and here all this time I thought my vehicle was powered by an
>|internal combustion engine, except for a very small electrical system.
>|What kind of car are *you* driving, Pat?
>|

>Last time I checked,  all my cars sub-systems used 12VDC.
>Let me know when your car starts running on 20KHz.

Last time I checked, your remark was that all vehicles were powered by
(not had a small DC subsystem for electrical power, but were POWERED
BY) DC.  They aren't.  And let me know the next time you plan on
having your car spend 30 years on-orbit, Pat.

>|>|The AC Alternative
>|
>|Well gee, Pat, you must live in a real chicken-and-egg dilemma for
>|your entire life.  It ain't gonna show up in the catalogs until it's
>|being used, and you don't want to use it until it shows up in the
>|catalogs.  Back to the caves, boys!
>|

>No,  But the school of engineering I come from says, that if
>you can order it froma catalog, Faster, Cheaper and better
>then you can make it custom, you are a FOOL to try to make it custom.

Realy?  Even if by doing it custom you can do a better job of it, more
fully meet the requirements, etc?  Sounds like you know about fools

alright, but not about identifying them.  Go try shouting in that
mirror again..

>You seem to put the most negative connotations on to the
>legitimate engineering criticism I raise.  I may prefer,  proven
>somewhat crude mechanics,  but I'll bet you my philosophy will
>get more hardware up, then your Gold Plated,  Boondogle Charging
>let's waste money, the more the merrier philosophy ever would.

I have yet to see you raise anytyhing 'legitimate'.  Quite the
reverse.  (think about it -- maybe you'll get it)

>|>Actually, i would imagine that 20Khz transformers would not
>|>be terribly efficient,  the Reactance of these is proportional
>|>to frequency.  I'd imagine the impedance losses,  may make High Frequency
>|>Transformers actually imprcatical.   DSoes anyone have the idea
>|>of the Inductance of a 50 KW transformer coil?  assume 208/480 volts,
>|>three phase.
>|
>|Somehow I suspect that the people doing the studies probably looked at
>|this issue, and I suspect they used a better tool than "Pat's
>|imagination".
>|

>Then Maybe Dave McKissock, wouldn't mind posting some of these analyses.

>I mean,  I imagine they were done?

And maybe he can't be bothered any further with you?  It would be a
feeling I could relate to until you learned some manners, even if you
prove incapable of learning any engineering.

>|
>|>|
>|>|AC System Frequency
>|>|
>|>|Since it is now clear that AC has many advantages and is the
>|
>|>I don't know why anyone is worrying about delivery costs,
>|>after all,  the shuttle flies up with dead head space, and
>|>that's free.  I mean if they have to haul up the module,
>|>why worry about some extra weight,  i mean it's marginal
>|>cost is only a little hydrogen.   :-)
>|
>|If this were convincing logic, we'd be hauling whatever we pleased to
>|orbit, since it would always fit in the "deadhead space".  The point,
>|Pat, is that if you don't have to lift X pounds of one thing you can
>|lift X pounds of something else if you want to.
>|

>Fred, you must have a poor memory, or a short attention span.
>In another thread flame,  Dennis wingo was arguing that spare
>mass wasted on a fueling flight was ir-relevant because
>it could be billed at the marginal cost for extra lift.

>He was roundly flamed for that suggestion.  I was merely using it
>to sarcastically justify a heavier electrical system weight.

I know he was 'roundly flamed'.  I was one of the people involved in
that discussion, or did that slip your mind?  Perhaps YOU are the one
with memory problems here?  Just a hint.  Sarcasm typically doesn't
come across very well on wires.  In any case, you're saying that the
mass savings from 20kHz are unimportant, but using a sarcastic
'proof'?  That seems to say you favor 20kHz power.  Or are you having
another memory lapse on this thread?

>|
>|>|there isn't a strong size and weight driver, pushing us above
>|>|that frequency region. If we're conserned about a manned
>|>|vehicle, we should probably move to at least 20 khz to get the
>|>|power line noise above the audio region. (That 400 Hz whine
>|>|in my airliner stereo head-set is really annoying if I have to
>|>|listen for very long).
>|>|
>|>I've worked in lots of industrial plants with louder things then
>|>some power noise.  Seriouly, i can't believe this would ever be
>|>a major criteria.
>|
>|Yes, but one would like not to have all that loud racket and vibration
>|on a space station.  Background noise *better* be a serious criteria,
>|since people are going to be stuck in that environment for months at a
>|time.
>|

>They are astronauts.  They can take it.  It's no worse then the
>constant low-level whine emitted by the Net:-)

>|>|But how high can we comfortably go? The answer comes from the
>|>|DC power processing folks. When we design DC to DC converters
>|>|in this power range, readily-available component technologies
>|>|for semiconductor switching devices, transformers, capacitors,
>|>|etc. limit us to a maximum frequency of about 50kHz. So if we
>|>|stay comfortably below that, and continue with our initial
>|>|thought to chose something close to 20 kHz, we can expect
>|>|to find a good selection of qualified power components and
>|>|materials, and a good body of design data, with which to
>|>|implement hardware designs.
>|>|
>|
>|>Gee, I look in a lot of electrical industry magazines,  and I see
>|>a lot of articles on problems caused by DC power processing.
>|>A large number of PC's plugged into one room, generate enough
>|>non-linear current and harmonic noise to be destroying conductors,
>|>transformers and switch gear.
>|
>|Gee, your point?
>|

>The article cites the number of qualified components available to do
>20KHz power work,  and my literature,  mostly complains about
>problems related to high frequency.

That's nice.  How much literature do you have on building space
stations?

>|>Plus, i have to wonder what kind of body of design data exists at
>|>50 KW.
>|
>|>So how does efficiency wise a DC-DC converter stack up against
>|>a motor/generator pair.  For large power generation i'd imagine
>|>it would be a lot more reliable, and able to handle transients a lot
>|>better.
>|
>|One would like to reduce high-inertia rotating equipment to a minimum
>|on a space station, Pat.  Otherwise, you spend a lot of fuel
>|cancelling out spins imparted to the station by rotating equipment.

>Given the presence of the alpha-gimbels,  the motor generator will
>quite nicely  complement the torque needed by the main axis of the
>station.  If anything, it would help reduce the load on the
>G&N System, providing a constant spin to these elements.

You are making a *lot* of magical assumptions here.

>|And solid state is always more reliable than anything involving moving
>|parts, as well as easier to repair/replace.  The equipment I used to

>Not neccesarily.  Depends on the quality of the Electronics,
>and the mechanicals.

Ceteris paribus, you stupid git.  Of course if the solid state stuff
is made out of Cheetos and string it probably won't be as reliable as
a moving part!  Basic rule #1 of engineering:  If it has to work for a
long time with minimal maintence, minimize the number of moving parts.

>|work on in the Navy took the 440 3-phase from ship's supply, used a
>|motor generator set to get DC (what we called 'quasi-DC', actually),
>|then used a solid state inverter set to convert it to high-current DC.
>|This was then reconverted to AC elsewhere in the system as needed.
>>Would you consider 1/4 Megawatt as 'high power'?
>>
>Reasonably.
>>
>>>Does that mean we are looking at 50,000 dollars/watt
>>>costs deployed?
>>

>Did your Naval system,  cost $50,000/Watt?

It also didn't fly on-orbit for 30 years.  You sure seem to have this
penchant for out of context clips.

>[ Citation List deleted]

>>
>>
>>>Interesting,  most of these papers are either NASA reports, or
>>>IECEC papers.  Kinda a small community.
>>
>>Well, that sure invalidates everything, doesn't it, Pat?

>No,  But it sure doesn't show the technology being used by
>a large community.  Means you have to be your global test bed.
>Installed Base, is oftentimes a significant engineering criteria.

What do you think NASA *does*, Pat?  Lots of things they use aren't in
'everyday use'.  Get back to me when/if you ever learn any manners or
anything about engineering.  Until then, don't be surprised if you get
all the attention you deserve.

--
"Insisting on perfect safety is for people who don't have the balls to live
 in the real world."   -- Mary Shafer, NASA Ames Dryden
------------------------------------------------------------------------------
[e-mail] - I don't speak for others and they don't speak for me.

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End of Space Digest Volume 16 : Issue 402
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