Space & Astronomy/Space and Astronomy (October 1993).iso/pc/text/spacedig/v16_2/v16no291.txt

Internet Message Format | 1993-07-13 | 35KB

Date: Tue,  9 Mar 93 10:05:32
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V16 #291
To: Space Digest Readers
Precedence: bulk


Space Digest                Tue,  9 Mar 93       Volume 16 : Issue 291

Today's Topics:
              ***  The Shuttles 5 computers. INFORMATION
                 20 kHz Power Supplies "blowing up"!
                            a shining wit
                        Aurora Update (2 msgs)
                            a whining shit
       Cyrano and the Ark (was Re: Ark Discovered on the Moon)
                           Gaspra Animation
                      NASP (was Re: Canadian SS
                   Pluto Fast Flyby post-flyby fate
                    Proposed Jupiter f/c/b mission
           SSF Resupply (Was Re: Nobody cares about Fred?)
                  The courage of anonymity (2 msgs)
                 Water resupply for SSF (?) (2 msgs)

    Welcome to the Space Digest!!  Please send your messages to
    "[e-mail]", and (un)subscription requests of the form
    "Subscribe Space <your name>" to one of these addresses: listserv@uga
    (BITNET), rice::boyle (SPAN/NSInet), utadnx::utspan::rice::boyle
    (THENET), or [e-mail] (Internet).
----------------------------------------------------------------------

Date: Mon, 8 Mar 1993 13:30:56 GMT
From: Luke Plaizier <[e-mail]>
Subject: ***  The Shuttles 5 computers. INFORMATION
Newsgroups: sci.space

        I am presently embarking on a year-long project to develop a fault
tolerant computer system by way of having 3 computers in a Triple mode
Redundant setup.

        I would like to find some information on the US Space Shuttle computer
system which has a Triple Mode Redundand system with 2 backup spares (At least
that's the way I've heard it before.) This is for the purpose of a display and
seminar which will provide 'glossy posters' for people to look at while I
continue the real work at hand.

        This request is for information of any kind - electronic or otherwise
- that may help in formulating a justifiable tie between my project and the
computer system of the shuttle.

        Please forward any information you have and are willing to release to
me at this email address.

        I thank you for listening to my plea for assistance and hope you live
and proper.


                                                        Ad Astra

                                                      Luke Plaizier
                                                University of Newcastle
                                                        Australia

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

Date: 8 Mar 1993 10:19 EST
From: "David B. Mckissock" <[e-mail]>
Subject: 20 kHz Power Supplies "blowing up"!
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Pat) writes...
>
>  Before they killed the 20 kHz power bus, the main power
>  supply design they had approved and were designed to use
> had a single fault failure mode that was explosive in
> nature. This is inside the Pressure vessel. The reaction
> of Management to this problem was "so what, no astronauts
> will be endangered, this will never fly anyway"

Balderdash. I was personally involved in the trade studies
performed at WP-04 over the power system distribution
frequency for SSF, and nobody in the program ever said
the power supplies were single fault tolerant and would explode.
To the contrary, 20 kHz was *safer* than DC, because faults
could be isolated faster.

Also, the scenario you describe "single fault failure mode"
would violate several SSF requirements in SSP 30000,
the SSF program requirements document.
  The EPS functions required for station survival shall be
  single-faulure tolerant with no degradation.
  Identified hazards which are evaluated to be critical
  shall be controlled such that no single failure or single
  operator error can result in the hazardous event.

Finally, concerning the supposed management statement of
"so what, this will never fly anyway", I have been in this
program for a decade, and I have never heard an SSF manager
ignore a potential hazard with the excuse that the vehicle
probably won't fly. Folks on sci.space love to speculate
that SSF managers are a bunch of idiots who really don't
care about the success or failure of SSF. My experience
with SSF managers (including the Level I program manager
Dick Kohrs, Level II managers Moorehead, Bensimon, Cox,
and *ALL* of the WP-04 managers) is that they are very
concerned with the success of SSF.

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

Date: Mon, 8 Mar 1993 16:32:40 GMT
From: Tim Pierce <[e-mail]>
Subject: a shining wit
Newsgroups: news.admin.policy,alt.privacy,comp.org.eff.talk,sci.space

In article <[e-mail]> [e-mail] writes:

>[e-mail] (Rich Kulawiec) says, in part:
>
>>This is ludicrous.  If you do not have the courage of your own convictions,
>>and are not willing to back those convictions up by using your own name,
>>why should anyone pay the slightest attention to you?  (I certainly won't)
>>Either you have the guts to back up what you say, or you don't; and if you
>>don't, then you should probably just be quiet.
>
>Right.  So -- Anne Frank should have kept her kvetching trap shut, right,
>right, Mr. Kulawiec?

I believe you owe the readers of soc.culture.jewish an apology for
such an insulting comparison to Anne Frank.

--
____ Tim Pierce                /           You never fuck me
\  / [e-mail] /              and I always
 \/ (BITnet: TWPIERCE@AMHERST) /             have to drive.

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

Date: Mon, 8 Mar 93 13:24:19 GMT
From: Dean Adams <[e-mail]>
Subject: Aurora Update
Newsgroups: sci.space

[e-mail] (Pat) writes:
 >> Designed and built at Lockheed Skunkworks in Burbank Ca.
 >Reasonable.
Yup.

 >>|- operational altitude: 100,000 to 150,000 ft
 >100,000 I can see, 150, would have to be some sort of ballistic shot.
Yea, 150K sounds a little too high.

 >|- 25 operational from tonapah Base Area 30 in Nevada
 >Grossly exagerated.
More than likely.  It also would have been operating
from Groom Lake, not Tonapah...

 >I don't think there were ever more then 12 SR-71s
 >operational, samething with U-2s.
I think there were more than that.  After all, 100 U-2/TR-1s were built.

 >if this thing is what it's cracked up to be,  you wouldn't need
 >more then 2-3 in say 4 bases worldwide.

I'm sure they would NOT be in "4 bases".  The SR-71 only operated
from two primary foreign bases.  I doubt an "Aurora" would have ANY.

 >from nevada,  you get to spy on panama and nicaragua,  but we overfly
 >them with TR-1's and RF-14s

From Nevada, a *Mach 6* vehicle could go just about anywhere...

 >Look at the old U-2 ops bases, or SR-71 bases.   Scotland, turkey,
 >pakistan, Nevada,  Japan,  Korea, Norway?   The places you want to see
 >are not in the western hemisphere.
The place we want to see is Groom Lake, NV!  :->

FYI, the SR-71 Detachment bases were Mildenhall, UK and Kadena, Japan.

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

Date: Mon, 08 Mar 93 16:15:23 MET
From: [e-mail]
Subject: Aurora Update

>|- funding in 1985: $2.3 billion
>
> 2.3 billion/year, over a 10 year program  with funding
>variation of 50%, i can see.  ... [stuff deleted] ...
>Pat (7 Mar 1993 14:58:13 -0500)

2.3 billion/year is not very different from the price of the B-2
program, as it was scheduled in the mid-80s: $ 36.6 billion,
beginning a little after 1980 (?), completion 1995 ("B-2 Peak
Production Delays Drive Up Program Costs", by Bruce A. Smith,
AW&ST, July 24, 1989). Could Aurora be the B-2 ? An indication
in favor this hypothesis can be found in what said the Pentagon
(could it be that they don't always lie ?):

NEW DAWN FOR AURORA, by Russ Britt, Los Angeles Daily News, May 17, 1992:
" ....  Aviation enthusiasts and analysts have mused over the plane's
 existence ever since a line item inadvertently appeared in a 1985
 Pentagon budget under the reconnaissance aircraft category with the
 code name Aurora.
    Pentagon officials claimed it was a reference to the B-2 stealth
 bomber, which was still secret at the time."

J. Pharabod

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

Date: Mon, 8 Mar 1993 16:42:43 GMT
From: Ken Garrido <[e-mail]>
Subject: a whining shit
Newsgroups: news.admin.policy,alt.privacy,comp.org.eff.talk,sci.space

[e-mail] (Jay Maynard) writes:

>>Right.  So -- Anne Frank should have kept her kvetching trap shut, right,
>>right, Mr. Kulawiec?

>This comparison is one of the most odious I've seen in a long time. Anne Frank
>was at danger of her life. You are not.

Excuse me, but  what does Anne Frank have to do with anonyminouty (sp)? As I
understand it, she was writing a personal journal, not submitting articles to
the Times-Herald, and she was long dead by the time anyone else read it.

So what are you two talking about ?

>--
>Jay Maynard, EMT-P, K5ZC, PP-ASEL | Never ascribe to malice that which can
>[e-mail]      | adequately be explained by stupidity.
> "Support your local medical examiner - die strangely." -- Blake Bowers
--
For just a minute there, I was dreaming/for just a minute, it was all so real
For just a minute, she was standing there with me...

Ken Garrido     [e-mail]     Martin Marietta Aerospace

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

Date: 8 Mar 93 10:57:10 -0600
From: Bill Higgins-- Beam Jockey <[e-mail]>
Subject: Cyrano and the Ark (was Re: Ark Discovered on the Moon)
Newsgroups: sci.space,sci.archaeology

I apologize for messing up my previous attempt to post this on Friday...
Let's try again.

In article <[e-mail]>, [e-mail] (Rich Travsky) writes:
> The following showed up on the sci.archaeology group. The article speaks
> for itself, as further words can hardly do it justice...
[He then quotes Eugene Powell ([e-mail]),  in an
article that relates to the recent Noah's Ark  controversy swirling
across sci.archaeology, sci.skeptic, talk.origins, and who knows where
else... a couple of Sundays ago a pseudoscientific documentary about
finding the Ark appeared on CBS, the network Walter Cronkite and Ed
Murrow used to work for.  The rest of the quoted material is Powell's:]

> It seems IYF TV, a new station on the upper reaches
> of the dial, will broadcast a story from Archaicology Magazine about
> half of the famous boat found (you won't believe this) on the moon!
[...]

Well, now, you may think that Eugene Powell is pulling your leg, but
wait! I have more evidence!

Take a look at Cyrano de Bergerac's (1619-1655) famous book,
*Historie Comique des Etats et Empires de la Lune*, often packaged
with its sequel *Historie Comique des Etats et Empires du Soleil*.
Being French-impaired, I've got Richard Aldington's 1962 translation
from Orion Press, *Voyages to the Moon and Sun*.  These stories are
often cited in histories of rocketry and of science fiction, because
in proposing  many methods of ascending to the Sun and the Moon,
Cyrano anticipated (in a loose sense) a few modern devices.  The books
were published posthumously, but I'd guess the events described in
them took place in the 1630s or 1640s.

Arriving upon the Moon, Cyrano discovered the Garden of Eden and met
the prophet Elijah.  Apparently quite a few characters from the Bible
made their way to the Moon by various means.  One of them was Achab, a
daughter of Noah.

As the rain fell and the Flood rose higher and higher, it eventually
reached the  level  of the Moon.  Achab left the Ark in a small
boat and grounded it on the lunar surface.

Is it possible that the boat-like fragments Powell speaks of
are the remains of Achab's boat, rather than the Ark itself?

The House Telecommunications Subcommittee  |
has scheduled a hearing on the issue for   | Bill Higgins
next Wednesday, featuring advocates of     | Fermilab
tougher regulation as well as Shari        | [e-mail]
Lewis, host of a children's show on public | [e-mail]
television, and her sock puppet Lamb Chop.  --*N.Y. Times*, 4 Mar 93, p. A9

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

Date: Mon, 8 Mar 1993 10:14:51 GMT
From: Tero Sand <[e-mail]>
Subject: Gaspra Animation
Newsgroups: sci.space,sci.astro,alt.sci.planetary

In article <[e-mail]> [e-mail] (Ron Baalke) writes:
>will work with CGA - I'm surprised anybody is still using CGA.  There is

Ah, I don't have choice in the matter (for now) - my computer is an
Apple IIGS*, and in it I have an IBM co-processor card, and it only
emulates CGA.

* Never mind. :-)

    Tero Sand
--
    EMail: [e-mail]   or   [e-mail]
   "I feel most ministers who claim they've heard God's voice are eating
too much pizza before they go to bed at night, and it's really an
intestinal disorder, not a revelation." - Reverend Jerry Falwell

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

Date: Mon, 8 Mar 1993 13:56:05 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: NASP (was Re: Canadian SS
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Dave Michelson) writes:

>I'm amazed that the NASP was even funded.  Back in 1978, the American Institute
>of Aeronautics (Technical Committee on Space Systems) concluded that:

>  "Rapidly evolving vehicle concepts and technologies point to the feasibility
>   of fully reusable Earth-to-orbit vehicles, including single-stage-to-orbit
>   (SSTO) transports, by the early 1990's....

I don't think it was ignored as much as you think. There have been a
number of classified programs working on SSTO over the past 12 years.
Two in particular called Science Dawn and Have Region produced detailed
designs and even prototype structures.

Let's hope DC gets funded.

  Allen

--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "A great man is one who does nothing but leaves        |
|  [e-mail]     |  nothing undone"                                       |
+----------------------990 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

Date: 8 Mar 93 13:29:36 GMT
From: Gregory P Dubois <[e-mail]>
Subject: Pluto Fast Flyby post-flyby fate
Newsgroups: sci.space

Pioneers 10 and 11, and Voyagers 1 and 2, in view of their solar system
escape trajectories, each carried some form of message theoretically
intended for the benefit of some extra-solar civilization that might one
day locate and salvage the spacecraft.  Leaving aside all the questions
which can be asked about the past efforts, given that the Pluto Fast
Flyby mission currently under consideration will presumably be on an
escape trajectory, does anyone know if there has been any serious
consideration of affixing some form of message to the two spacecraft?
Given the weight restrictions, presumably something either much more
modest or much more weight-efficient than the Voyager record would be
necessary.  I would be very sympathetic to claims that every gram of
payload should be used for science, but it seems nonetheless an obvious
question.

On a more serious note: given the limited complement of instruments and
the desire to keep operating and overall life-cycle costs down, is it
envisioned that the PFF spacecraft will do any science after the flybys?
At the very least, I would imagine they could do radio science and
participate in, e.g., gravity experiments.  Would they be able to say
anything about the heliopause, and for how long could we stay in contact?

I realize this is all very premature and that there is no stable design
yet, but perhaps it would still be interesting to hear some speculations.

Gregory Dubois

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

Date: Mon, 8 Mar 1993 14:09:42 GMT
From: [e-mail]
Subject: Proposed Jupiter f/c/b mission
Newsgroups: sci.space

Last week Bill Higgins wrote:

>...you might look at the Discovery Program Workshop report.
>A Jupiter mission is pretty hard to do on $150M, but there is one
>tricky candidate.  I don't know if it counts as a followon by your rules:

>          % Earth Orbital Ultraviolet Jovian Observer will study
>the Jovian system from Earth orbit with a spectroscopic imaging
>telescope.  Principal Investigator:  Paul Feldman, Johns Hopkins
>University, Baltimore.

Since I've had the pleasure of working with Paul Feldman in the past
executing some of his HST proposals, I thought I'd go on and ask him
for some more information about this.  The following has been extracted
from the information packet he put together for the Discovery Workshop
on Nov 17, 1992.

EARTH ORBITAL UV JOVIAN OBSERVER

Investigators:  Fran Bagenal, Univ of Colorado
        Michael J. S. Belton, NOAO
        A. Lyle Broadfoot, Univ of Arizona
        John T. Clark, Univ of Michigan
        Alan Delamere, Ball Aerospace (Technical Lead)
        Paul D. Feldman, Johns Hopkins Univ (PI)
        Arthur L. Lane, JPL
        David Skillman, Goddard SFC

Objectives
    Focused, low-cost mission to study the Jovian system from
    Earth orbit through ultraviolet (550 - 1750 angstroms)
    spectroscopy and extrame ultraviolet (EUV) imaging.

    Investigation of long-term temporal behavior of both Jupiter
    and the Io plasma torus.

Approach
    Integrated spacecraft and scientific instrument.

    Utilize state-of-the-art off-the-shelf technology already
    developed for NASA and DoD missions.  No new development.

    0.6 meter telescope in HEO (L1 point)
    [the L1 point is the sunward Lagrange point]

    Continuous viewing of Jupiter over 8 month period

    Short time (< 3 years) from project start to launch

    Single mission objective reduces cost of ground operations

    Additional solar system science objectives (e.g., comets)
    possible after end of Jupiter observations

Proposed Telescope Optics and Instrumentation

   Telescope
    60 cm diameter Cassegrain f/17 telescope design
    Normal incidence optics using Silicon Carbide (SiC) coatings
    to optimize UV signal

   Pointing Control
    Focal plane visible light CCD fine error sensor for
    accurate pointing; selection of imaging or spectroscopy
    requires no moving parts

   Science Instrumentation
    EUV Imager -- Spectral bandwith from 700 to 1450 angstroms.
    The detector is a 224 x 960 pixel MAMA (Multi-Anode Microchannel
    plate Array) with a KBr (Potassium Bromide) faceplate, and a
    pixel size of 25 um = 0.5 arcseconds on the sky.

    Long-slit Imaging Spectrograph -- Spectral range from 550 to
    1750 angstroms.  This instrument also uses a 224 x 960 MAMA
    detector, but with a CsI (Cesium Iodide) faceplate.  It utilizes
    a 300 line per mm toroidal diffraction grating.  Spectral
    resolution is selectable for delta lambda either 2.5 or 10 angstroms.
    The slit subtends one second of arc width on the sky.
    The spectrograph has a 40 cm focal length and a f/17
    focal ratio.  The pixel scale in high resolution mode
    is 1.25 angstroms per 25 um pixel.

As I mentioned above the planned orbit is at the L1 Lagrange point.
The mission would be launched aboard a Delta II and would employ
one ground station at Goddard Space Flight Center.  Data storage would
utilize 250 Mbit solid state memory, and there would be one data dump
per day.  This provides for a minimum of ground support.

The spacecraft has a design lifetime of two years, and an expected
mission duration of one year.

-Bill Gawne,  Space Telescope Science Institute

 "Forgive him, he is a barbarian, who thinks the customs of his tribe
  are the laws of the universe."                       - G. J. Caesar

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

Date: Mon, 8 Mar 1993 13:47:47 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: SSF Resupply (Was Re: Nobody cares about Fred?)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Gary Coffman) writes:

>That's not true. NASA's budget is around $14 billion. Even the pessimists
>grant that Shuttle's operational budget is around $3.5 billion a year.

Plus a billion or so on sustaining engineering and NASA overhead. All
together we are looking at about $5B a year.

>There's dispute over how to account for some of the standing army, but
>that includes costs directly associated with Shuttle.

But not all costs. There is a lot of bootleg money skimmed off by center
managers. For example, at JSC about half of the engineering directorate
is working on Shuttle. Yet as near as I can tell, Shuttle money isn't
funding these people.

>If you look only
>at incremental costs, a Shuttle flight costs around $300 million tops,

More like $100M. However, this is a rather bogus figure since there are
no incrimental flights possible.

>perhaps as little as $180 million depending on flight frequency and other
>issues. In neither case is Shuttle's budget HALF of NASA's budget.

Some estimates which loot at total spending, not just appropriated
line items, disagree. Shuttle could be consuming half the NASA budget
but NASA accounting is so poor its hard to say.

  Allen

--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "A great man is one who does nothing but leaves        |
|  [e-mail]     |  nothing undone"                                       |
+----------------------990 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

Date: Sun, 07 Mar 93 00:58:21 EST
From: Ben Coleman <[e-mail]>
Subject: The courage of anonymity
Newsgroups: news.admin.policy,alt.privacy,comp.org.eff.talk,sci.space

[e-mail] (8 February 1993) writes:

> Yes, it takes more effort to get your mind around anonymous
> posts than attributed ones: we get out of the habit of
> evaluating arguments without the guiding badges and trappings
> of authority accompanying them.  Those posters who have
> forgotten how to legitimately persuade and, through time and
> accreting rank, have relied upon the prestige of their
> posting site may well have reason to fear the new order of
> things.

I'm afraid all you've done for me with this argument is to further
persuade me that C. S. Lewis's term "Bulverism" ought to be brought back
and dusted off so we'll have an appropriate label for these kinds of
argument.

Ben

+---------------------------------------+---------------------------------+
| Ben Coleman NJ8J                      | "All that is not eternal is     |
| Packet: NJ8J@W4QO.#EAL.#ATL.GA.USA.NA |         eternally irrelevant."  |
| Internet: [e-mail]          |                                 |
|      or   [e-mail]  |                  C. S. Lewis    |
+-------------------------------------------------------------------------+

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

Date: Mon, 8 Mar 1993 16:00:41 GMT
From: Dillon Pyron <[e-mail]>
Subject: The courage of anonymity
Newsgroups: news.admin.policy,alt.privacy,comp.org.eff.talk,sci.space

In article <[e-mail]>, [e-mail] (8 February 1993) writes:
>It's been six weeks now since I posted the original
>"Challenger" article to sci.space and sci.astro as a
>contribution to the on-going thread reminiscing on the
>tragedy.  I am still surprised at the intensity of negative
>reaction that several posters had to the article and
>by association to the concept of anonymous posting.

The article was recycled tripe.
>
>While the usual reader of those newsgroups may be far more
>comfortable with the inhuman aspects of space flight --
>metric tons of fuel, pseudoinverse trajectory calculation,
>torrs of Oxygen, kilos of payload -- I believe that the
>phenomenon of crewed space flight is far more interesting at
>the sharp human edge, the sharp edge that cuts a thin bead of
>blood into the skin.

Then talk about people, about personalities, about the stress and strain of
development, testing and operation.  Don't talk about crap that was published
several years ago, and refuted almost instantly.
>
>Looking at political issues of funding and priorities as well
>as the social consequences of space exploration, many of us
>believe that the human angle is far more important, but fluid
>and ill-defined, than the technical problems of space travel.
>This protean quality of the human issue makes for many of us
>a more interesting challenge to understand and integrate
>into the whole picture than the relatively more deterministic
>mechanical issues.

Like I said, then talk about those issues, not crap.
>
>Sci.space and sci.astro need many more blunt posts centered
>on the human theme, even if strong medicine to many readers.
>

One more time ...
>As far as anonymous postings in general, the threats of
>personal violence that the Challenger post unearthed, for me,
>more than confirmed my decision to use it.  The contrary
>arguments that legitimate science will be swamped with
>anonymous bacchanals is simply not happening, even though
>over 20,000 people now have used the Finnish anon service.
>The newsgroups have approximately the same mix of surplusage,
>truth and tripe as they always have had.  The imminent death
>of the sci. and comp. groups seems a bit presumptuous.
>
>I think it takes far more courage to post anonymously than to
>hide behind your affiliations.  For me, a poster who,
>although anonymously, slowly built a strong argument through
>a series of well-written anonymous posts and politely
>responded to counterexamples and the other stuff of a good
>debate, would capture my respect far more than Dick
>Reputable, [e-mail] making a simple pronouncement on
>the whole matter that his net-flacks are expected to parrot.

I read and accept Henry Spencer's posts, and the only credentials he posts are
that he is somehow associated with the University of Toronto Zoology department
and, from other posts, something of a UNIX and NNTP wizard.
>
>Yes, it takes more effort to get your mind around anonymous
>posts than attributed ones: we get out of the habit of
>evaluating arguments without the guiding badges and trappings
>of authority accompanying them.  Those posters who have
>forgotten how to legitimately persuade and, through time and
>accreting rank, have relied upon the prestige of their
>posting site may well have reason to fear the new order of
>things.  But the content of the argument ought to be
>important for all posters, not just the ones who do not have
>a Keogh plan or a doctorate. Certainly most scientists agree
>that the necessity of experimentation, systematic
>observation, and falsifiability supporting a scientific truth
>applies equally to the member of the Academy as well as the
>first-year lab assistant.
>
>The concept of anonymous posting is the next great step in
>washing away the detritus that impedes our search for truths.
>Yes, it has a great capacity to annoy and anger, but it has
>an even greater capacity to engage the truth for those with
>courage enough to learn to use it universally and well.

You way you can improve your credibility is to go back to your doctor and ask
for some Stellazine and Trilifon and Benedryl for the sides.
--
Dillon Pyron                      | The opinions expressed are those of the
TI/DSEG Lewisville VAX Support    | sender unless otherwise stated.
[phone] (when I'm here)     |
[phone] (when I'm home)     |When in fear, or in doubt
[e-mail]          |Run around, scream and shout.
PADI DM-54909                     |

And I apologize to the rest of your for burning your disk space and personal
time.

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

Date: Sun, 7 Mar 1993 07:46:04 GMT
From: Nick Szabo <[e-mail]>
Subject: Water resupply for SSF (?)
Newsgroups: sci.space

[e-mail] (Gary Coffman) writes:


>Deployment and aiming are the
>stickiest problems associated with sails, or flexible mirrors.
>Remember that we're talking about an organization that can't get
>an antenna to deploy, or a winch to reel out cable.

Gee, I get to upbraid Gary for NASA-bashing!  NASA has successfully
deployed several large antennas on its TDRSS series without a hitch.
The U.S. military has deployed dozens of these, including 100-ft. monsters.
The Russians recently tested their solar mirror (any news on that?).
Henry Spencer's small group apparently thought such deployments are
feasible on the cheap.

I didn't say deployment was simple; I just pointed out it doesn't
require advanced AI, anthropocentric robots, and other strawmen
that the Luddites keep raising against automated missions.  The
volatile extraction business scenario assumes odds of deployment
failure similar to those on commercial or military systems, and
involves dozens of small ice rockets, not one big one.  I never said
NASA should do this project; rather they should study it, R&D to
the prototype stage, buy the product, and above all include it in
their vision of the future.  We space activists also need to include
it in our vision of the future.  The mission itself should be
commercial, with multiple international customers not detailed-spec
contracts from a single government agency.

Complexity is a function of quality, not quantity.  If a large-scale
volatile extraction mission is more complex than Rosetta it would
be due to differences in complexity between keeping a material
pure and purifying a material, not due to differences in the
volume of material.  Those are two different tasks, but
I'm not convinced that one is substantially more complex than the
other; even less am I convinced that this requires as-yet-undiscovered
AI or anthropomorphic robots.  Both missions require very good
quality control, software engineering, and mission planning, and for
Rosetta sample return most space scientists and engineers figured
this was quite doable by the mid-1980s.  The state of the art has
advanced quite a bit since then with VR, teleprogramming, and the
deployment of many different kinds of ocean-going remote, automated
oil drilling and well maintenence equipment.  This equipment works
in a similar environment (mud & organics & water) with high
mass-thruput ratios (even though mass is not much of a consideration
in the ocean, so this variable could likely be improved substantially
for space missions with high-strenth polymers, miniaturization, etc.)

Likewise, there is no necessity to follow your pilot-plant
development plan so strictly.  Oil companies every year drill
through miles of rock, gravel, mud, permafrost, ice, etc. that
they haven't mapped out in detail beforehand.  Similarly
mineshafts and tunnels are drilled, etc. with general-purpose
equipment through highly variable and not necessarily
predictable geology.  The comet mining equipment will be
extensively tested on Earth, and in microgravity in low earth
orbit, and designed to handle a wide variety of comet surface
conditions.  Techniques for mapping and adapting to a wide
variety of comet surfaces should be developed for the comet
sampling probes, a task appropriate to NASA.  The first missions
to the comet will be high risk and high payoff -- reducing the
cost of materials in earth geosynchronous orbit by two orders
of magnitude, for example.  The first missions will be operational.

Even though oil workers are orders of magnitude less expensive than
astronauts, oil companies are starting to find such automation worthwhile.
We're also starting to see automation applied in Antartic science
(robot airplanes, Dante, etc.) even though the scientists there are
also orders of magnitude less expensive than scientists in space.
As the oil companies, Antartic scientists, etc. demonstrate the
equipment and work out the bugs (I will be the first to admit there
are bugs!), the objections to automation will evaporate in the face
of demonstrated technology wrt any serious commercial proposal to
process materials native to space.  (I'm sure those seeking NASA
Moon-base & Mars-mission contracts will continue touting astronauts
and bashing automation for some time to come, even as they do
"space resource" studies here and there for PR effect, but vying
for NASA contracts is not what I mean by commercial).


--
Nick Szabo                     [e-mail]

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

Date: Mon, 8 Mar 1993 15:06:01 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Water resupply for SSF (?)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Nick Szabo) writes:
>[e-mail] (Henry Spencer) writes:
>>The deployment phase is the single diciest part of a sail design...
>
>Nevertheless, you think a small group of volunteers can pull it off,
>no?  I'm arguing the Russians can pull it off, a small group of highly
>paid commercial professionals can pull it off, etc.  Mirror
>deployment isn't anywhere close to being a show-stopper that would
>cause us to throw up our hands and say, "we need astronauts!", as Gary
>implied.

No, no, no, I outright *said* we can't *afford* astronauts for these
missions. I didn't imply they were necessary at all. I did say the
job would be much easier *if* we could afford, technically as well
as fianancially, to send humans, but we can't.

>>[Rosetta']s been considered worth a try, as a high-risk
>>high-payoff mission, since the mid-1980s.  As I recall, problems like
>>preservation of the samples during return were considered minor ones
>>compared to the difficulties and uncertainties of the comet-surface
>>operations.
>
>The uncertainties are similar for both Rosetta and comet mining,
>regardless of material volume.  These uncertainties weren't anywhere
>close to being a show-stopper.  The probe sends back detailed pix
>for over a month, so that the best site can be picked, and can relocate
>of the first landing site doesn't work.  Rosetta-type missions develop
>this kind of technique reducing the risk of commercial mining

I also agree that precursor flights, many, are needed to develop
technique as well as doing survey work. I do contend that scale
is a major factor, however. Historically, table top models have
not scaled to pilot plant or production plant sizes without major
problems and major design changes. When the mass flow is measured
in tonnes rather than grams, processes usually have to change.

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     |                     |

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

End of Space Digest Volume 16 : Issue 291
------------------------------