Space & Astronomy/Space and Astronomy (October 1993).iso/pc/text/spacedig/v15_6/v15no606.txt

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Date: Tue, 29 Dec 92 05:15:12
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V15 #606
To: Space Digest Readers
Precedence: bulk


Space Digest                Tue, 29 Dec 92       Volume 15 : Issue 606

Today's Topics:
                           "Slick" Goodlin
                             Acceleration
                       Aluminum as rocket fuel?
                            Dante Advisory
                         Denver NASA Meeting
       How much radiation can an organism survive? (Panspermia)
             Justification for the Space Program (5 msgs)
                  Manhattan DISTRICT (not Pr......)
                         satellite costs etc.
                      Shuttle costs vs DC costs
                     Stupid Shut Cost arguements
        Stupid Shut Cost arguements (was Re: Terminal Velocity

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

Date: 29 Dec 92 03:37:00 GMT
From: SNOMCB <[e-mail]>
Subject: "Slick" Goodlin
Newsgroups: sci.space


 Just out of curiousity can anyone tell me whatever happened
to Chalmers "Slick" Goodlin? Cannot seem to find anything
about him after his hot shot days at Muroc, aka Edwards AFB.



Mike Bishop
SAS Institute Inc.
Cary NC

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

Date: Mon, 28 Dec 92 22:35:07 EST
From: John Roberts <[e-mail]>
Subject: Acceleration

-From: [e-mail] (Pat)
-Subject: Re: Acceleration
-Date: 27 Dec 92 18:04:22 GMT
-Organization: UDSI

-In article <[e-mail]> [e-mail] (_Floor_) writes:
->In article <[e-mail]> [e-mail] (John Roberts) writes:
->] That applies to things that are somewhat resiliant (like humans with their
->] limbs not locked), because if deformation continues throughout the period
->] of acceleration, then the entire body is not really subjected to the full
->
->Hmmm...you think maybe rigidity has something to do with this?
->If something is rigid, it is much more likely to break than something
->flimsy, which will bend.  Electronics certainly canot be built in
->a manner that will bend. Any flexing of the probe would have to
->be somehow accounted for in the design.

-Certainly electronics can be built to be flexible,  it's just what degree
-of flexibilty you desire.  Flex is a stress/strain relationship.
-Steel is flexible, rubber is rigid.  you just need to define these terms
-first.  besides, if you build with amorphous materials,  you can get
-quite a flex out of silicons.

Are the solar panels of HST made of amorphous silicon? They were rolled up
very tightly before deployment.

Something that didn't get adequately covered in the previous posts: in both
mechanical and electrical systems, there's a significant difference between
*being able to survive* a period of high acceleration or intense vibration,
and *continuing to operate* during that period. The hard disk drives in the
laptop computers used in the Shuttle generally survive the vibrations of the
launch, but they're not expected to run during that time. If an electrical
system uses spring-loaded contacts, an intense shock may cause the contacts
to open momentarily. I just got some literature from a company at the
Technology 2002 conference that makes metal-on-silicone contacts that are
rated for 50 G - there may be other kinds of contacts for more demanding
situations. Come to think of it, the components I'd worry about the most are
the oscillators - anybody know if it's possible to make quartz crystal
oscillators sturdy enough to continue working under an acceleration of
thousands of gravities?

-and i believe the designers understnad the material characteristics
-of their probes quite well.

I'm inclined to agree - the Galileo atmospheric probe's designers must have
considered acceleration and vibration in their design.

->] But other than that, and factors such as prolonged stress on human hydraulic
->] systems, the greater problem can be with rapid changes in acceleration, which
->] are of course associated with short bursts of acceleration. (I believe the
->] usual term for the time derivative of acceleration is "jerk".) These rapid

-Actually,  i think the term is Impulse.

You inspired me to look it up in a reference book:
 # impulse [MECH] the integral of a force over an interval of time.
 # jerk [MECH] the rate of change of acceleration; it is the third derivative
     of position with respect to time.

 (from the McGraw-Hill Dictionary of Scientific and Technical Terms, 1989)

->You're joking me if you think the Galileo probe will experience constant
->deceleration. There's going to be buffeting worse than we could imagine,
->I imagine (:-). Especially at speeds many times that of sound (which I'm
->sure will be different for the Jovian atmosphere)! So you're point is
->very applicable. Experiencing this jolting for milliseconds (as per
->a dropping watch) may not cause any damage. But if you dangled the watch
->from the ceiling and proceeded to place a jackhammer at its face,
->slamming into its face for a couple of minutes, liklihood is that
->the watch will no longer function! Ditto for an atmospheric probe.
->That thing is going to get one whale of a beating. You've helped me
->emphasize my point even more! Thanks :-)

-Hopefully this kid will take a physics class.

-I think he is mistaking  Work with Force and energy.

I think he's introducing the concept of cumulative damage where it might
not be applicable. If the magnitude of the forces and the margins of the
design are such that there is some cumulative damage (i.e. fatiguing of
components that flex slightly), the system could still be designed so that
it's likely to survive days or months of such conditions. That's another
design parameter that can be tested prior to launch.

-Work is force through a distance,  Energy is work*time, Force is mass*Accel
-( boy i hope i got these right :-) )

You got work and force right, but energy is power * time. Energy is the
generic term, while work, heat, etc. are alternate ways of expressing it.
They can all be expressed in the same derivative SI units (joules, for
instance). Power is energy (work, heat flow, etc.) divided by time.
Joules are kg * m^2 / s^2. Watts (power) are kg * m^2 / s^3.

It should be noted that in some calculations, "per unit time" or "per unit
area" or "per unit mass" is taken for granted, and is implicit in the
expression of the problem. That's just a shorthand notation, to avoid having
to carry the units through all the calculations.

-It takes energy to achieve a momentum change.

-A probe has high momentum hitting atmosphere.  it gets  a high acceleration,
-on a small mass.  not a lot of force,  exerted through several miles of
-atmosphere,  for a few minutes.

-I think the kid is missing the fact that while the accelerations of dropping
-a watch and hitting it with a sledge are the same, the work products are significantly  different.

If you smash the watch between two objects, then college-freshman-type
mechanics is no longer a good way to describe the system. All sorts of
complex materials properties start to come into play.

-Try this.   drop a timex.  work out the acceleration.

You have to make a guess at the degree of deformation, which is very
nontrivial. If you assume no deformation, then the peak acceleration
comes out infinite.

-Now,  hang the timex from a string.   Let a pendular mass strike it, at low spe
-ed.  work out the acceleration.  keep increasing the mass and speed.
-continue until the timex dies.   I suspect you will be surprised at how
-high you can go.

Same problem. You might be able to work out a lower limit for peak
acceleration, accepting that the peak is probably *much* higher than
this lower limit.

John Roberts
[e-mail]

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

Date: Mon, 28 Dec 92 22:48:54 EST
From: John Roberts <[e-mail]>
Subject: Aluminum as rocket fuel?

-From: [e-mail] (John Thompson Reynolds)
-Subject: Aluminum as rocket fuel?
-Date: 28 Dec 92 14:36:43 GMT
-Organization: HaL Computer Systems, Inc.

(Appropriate last name for such a question. :-)  :-)

-I've seen references in the past which suggest using Lunar O2 and Aluminum
-as rocket fuels.  Have there been any fairly detailed designs of how such
-a beast would be constructed?  Perhaps a hollow cylinder of packed Aluminum
-dust into which LOX is pumped?

Here's the only fairly solid reference I've come across. If you could
contact the company and post some information, the readers of sci.space
would be very grateful.

An aluminum-oxygen engine could potentially be very useful for launch from
the moon, since both materials are abundant there (and hydrogen is at best
very rare, and therefore valuable). I expect the specific impulse isn't too
great, but you don't need a very high specific impulse to escape from the
moon.

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

>From: [e-mail] (Bev Freed)
Newsgroups: sci.space
Subject: Toward 2001 - 02 Dec
Message-ID: <[e-mail]>
Date: 3 Dec 91 02:05:21 GMT
Organization: The NSS BBS, Pittsburgh PA [phone]

                            ***********
                            TOWARD 2001
                            ***********
                      Week of 2 December 1991
--------------------------------------------------------------------
This information is reproduced by permission of the Space Age
Publishing Company.  All rights reserved.  Copyright December 2,
1991...
====================================================================
                           * * * * * * *
+ Wickman Space and Propulsion
Sacramento CA

Lunar soil broken down into liquid oxygen and aluminum powder powers
a new engine being developed by Wickman engineers. A subscale engine
has been sucessfully tested for periods of up to 35 seconds at
varying levels of thrust.
                           * * * * * * *
--------------------------------------------------------------------

John Roberts
[e-mail]

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

Date: 28 Dec 92 21:16:00 GMT
From: Ron Baalke <[e-mail]>
Subject: Dante Advisory
Newsgroups: sci.space,alt.sci.planetary,comp.robotics

Charles Redmond
Goddard Space Flight Center, Greenbelt, Md.   December 28, 1992
(Phone:  [phone])

DANTE ADVISORY

ROBOT AND TEAM ARRIVE SAFELY AT MT. EREBUS BASE CAMP

    Dante, an 8-legged NASA Robot, and the twelve member
government/university team undertaking the robotic exploration,
have arrived safely at the base of the live Antarctic volcano,
Mt. Erebus.  The team has successfully established
telecommunications between themselves and the Goddard Space
Flight Center via the NASA Tracking and Data Relay Satellite.

    There is the possibility the Antarctic team might be able
to transmit at 4:20 p.m. and at 5:30 p.m. EST today video of
their preparation activities taped during the past several
days.

    When Dante begins its descent into the crater of the
volcano, the team will provide live video during several 20-
minute feeds a day.  These feeds will occur during 8:00 am and
4:00 pm.  The earliest the team estimates the descent will
occur is no sooner than Wednesday, Dec. 30.  There is no
current estimate of the time of these feeds.  Also, local
weather is a factor and the team is taking longer than
orginally expected to accomplish certain tasks, so the estimate
of Wednesday could be early.

    The robot's exploration down the steep inner rim of Mt.
Erebus to the lava lake of the Antarctic volcano is a
technology demonstration and science expedition between NASA
and the National Science Foundation.   For most of the robot's
expected exploration activities, it will be under the local
control of the Antarctic team.

    However, portions of the robot exploration will be
controlled from a payload control center at Goddard.  This will
be the longest distance ever for live robotic control and
simulates what may be in store for NASA's further exploration
activities with humans and robots on Mars.  Carnegie-Mellon
University and the New Mexico Institute of Mining and
Technology are partners with NASA and the NSF as robotics and
volcano experimenters.

    Robotic exploration of the live Mt. Erebus volcano will
take a minimum of 3 days.  Each day, the Antarctic team expects
to transmit five 20-minute live video feeds from cameras
mounted atop the robot or from atop rim of the volcano.

    The feeds will be transmitted from Mt. Erebus via NASA's
Tracking and Relay Data Satellite West to Goddard.  NASA will
issue further media advisories when the dates and times of the
feeds are  known. (Call 301/286-6397 for recorded update
information.)

    NASA also will provide commentary on the robot's progress
provided by robotics and volcano experts at Goddard.  The
television feed and commentary will be available both at
Goddard and on NASA Select Televison.


-end-

     ___    _____     ___
    /_ /|  /____/ \  /_ /|     Ron Baalke         | [e-mail]
    | | | |  __ \ /| | | |     Jet Propulsion Lab |
 ___| | | | |__) |/  | | |__   M/S 525-3684 Telos | Choose a job you love, and
/___| | | |  ___/    | |/__ /| Pasadena, CA 91109 | you'll never have to work
|_____|/  |_|/       |_____|/                     | a day in your life.

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

Date: 28 Dec 92 23:07:43 GMT
From: Jeff Stoner <[e-mail]>
Subject: Denver NASA Meeting
Newsgroups: sci.space,sci.astro

In recent postings by Ron Baalke of the Space Calendar, there's a
"NASA Town Meeting" listed for Denver, Colorado in January 1993, with
no other information or specific date.

Does anyone else know more about this? I'm especially interested
since I live in the area.

Thanks!

--
====== Jeff L. Stoner === Boulder, Colo. ============ /\ = /\ ========== |
                                                 /\  /  \ /  /\  /\    --*--
   Home: jls2 @ bearhug.boulder.co.us         /\/  \/    /  /  \/  /\    |
   News: jls2 @ csn.org                    /\/  \   \  /\  /    \    /\

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

Date: 28 Dec 92 22:58:41 GMT
From: "David M. Palmer" <[e-mail]>
Subject: How much radiation can an organism survive? (Panspermia)
Newsgroups: sci.space,sci.bio,sci.med.physics

The Panspermia hypothesis is that after life originates on one
planet (or in a molecular cloud, or whatever) it can be transported
by natural causes to other planets, so that life need be created
only once per galaxy (or universe) in order to become widely
distributed.

People have found that microbes of some sort, when ensporulated
(is that the right word?  dormant anyway) are very resistant to
radiation, and thus could make the trip from star to star, enter
a sterile but nutritious environment, and start living, reproducing,
evolving and generally creating a biosphere.

I personally don't believe that this happens very often, but it's
an intriguing idea.

Anyway, does anyone have a reference for the work on the microbe
spores?  I am interested in exactly how much radiation these
things can take.

Thanks in advance.

--
        David Palmer         [e-mail]

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

Date: Mon, 28 Dec 1992 22:32:26 GMT
From: "Dr. Norman J. LaFave" <[e-mail]>
Subject: Justification for the Space Program
Newsgroups: sci.space,talk.politics.space

In article <[e-mail]> Paul Dietz,
[e-mail] writes:
>Since your reasoning seems inherently incapable of being disproved,
>even if wrong, I don't see that it has any value.

My arguement has the benefit of centuries of historical precedent
which is more than your "There will never be benefits worth the
expense" arguement you are spouting which can be
easily argued against using the same historical
information. Can I prove my assertion?
No. However, neither can you prove the contrary. The overwhelming
number of historical accounts which support my point makes the
effort of space exploration worth the risk.

I would rather be bold and take risks in the hope of expanding my
horizons than sit around dumb, happy, and complacent
while we slip into decline.

Let me clue you into something....there are many phenomena in this world,
which appear to be true due to overwelming evidence, which are neither
well-understood or structured enough to be "proven". A
given phenomenon is believed
to be true because either a.) The phenomenon always occurs, or b.) The
phenomenon happens the vast majority of the time, or c.) It can be
rigorously proven to be true. Choice c.) may be superior to the other two,
but it is not the only method which defines "belief of validity". Indeed,
most of our experimental science is based on a.) and b.) for its
foundation.

>Theories have to be
>falsifiable to be useful.

Untrue. Theories need only be logical, and self-consistent
with experience, to
be useful. Theorists develop and study theories that lack
definitive proof all the time.

>In practice, you *will* have to argue that
>a project has specific benefits or it will not be funded (or, rather,
>you won't get funded for your *next* project, as with Apollo).

And this is what is wrong with the whole system. Hundreds of
examples of
pure science leading to unforeseen applications and unheard of prosperity
are ignored in favor of safe, incremental development which barely
keeps our economic head above water. This is not the way our society
became great. Taking risks use to be the ideal in this
country and lead to our greatest achievements and our economic
and technical superiority.  We have lost these benefits due to our
timidity and lack of foresight.

>
>You mention comsats, etc.: yes, but that has little to do with the
>Club of Rome/wild schemes of space resource exploitation that started
>this thread.

Satellite communication was once thought of as wild fantasy too. Surely
you have more perspective than this. You are only making my
point for me.

>Moreover, these benefits were not unpredicted: Clarke
>forecast geostationary communication relays in 1947.

Clarke was a visionary, as has been many science fiction writers
(Jules Verne, Micheal Crichton, H. G. Wells,...).
The predictions of a science fiction writer may indeed come true, but
they are not the same as the predicitons of engineers and scientists
in their same field of endeavour. Furthermore, this does not negate
the fact that benefits are already here that
short-sighted people like you would have
killed before fruition if you had been allowed to do so. You would
have claimed that communication by satellite was a
"Club of Rome/wild scheme" and dismissed it as the ravings of "zealots"
(I'm a zealot too!!).

Paul, we have been round-and-round about this before.... I suggest
that you are in dire need of a history of science and technology
course or need to read the writings of the great scientists to know
how little they understood the awesome potential of their
discoveries.

Dr. Norman J. LaFave
Senior Engineer
Lockheed Engineering and Sciences Company




When the going gets weird, the weird turn pro
                               Hunter Thompson

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

Date: Mon, 28 Dec 1992 19:09:41 GMT
From: Mike Kirby <[e-mail]>
Subject: Justification for the Space Program
Newsgroups: sci.space

In article [e-mail], [e-mail] (Paul Dietz) writes:
>In article <[e-mail]> Dr. Norman J. LaFave <[e-mail]> writes:
>>In article <[e-mail]> Paul Dietz,
>>[e-mail] writes:
>
>
>The differences between the age of exploration and today are
>considerable.  The raw mineral and agricultural products (and slaves)
>that profited the explorers of that age are a much smaller fraction of
>GDPs today.
>
>More generally, arguments by analogy are essentially circular.  You
>have to assume that the analogy is valid to believe the argument.  I
>don't see any reason to do that here.  There are contrary analogies:
>for example, exploration of Antarctica has been of little practical
>benefit to the exploring countries (although it has been of scientific
>benefit to humanity as a whole).
>
>    Paul F. Dietz
>    [e-mail]


It seems that a reasonable justification for space exploration is simply that.
It is there.  Your analogy of Antarctica is very relevant.  Although it has not
been a great financial success, it has been of scientific benefit.

By that same argument exploration of space could give us the same scientific benifit.

Similarly, exploration of the deep seas is of little economic benifit, but scientifically it allows us to learn more about our planet.

So.  The original question was should we spend tax-payer money to explore space.  I
think paul has given us the answer.  That answer is yes.  We can spend taxpayer money
to explore for scientific research.  However, taxpayer money should not be spent
to help to government extract economic advantages from space.  (which is reasonable,
that is what private industry is supposed to do).

Perhaps we should form a government agency that is responsible for the development
and exploration of the scientific aspects of space.  Gasp, Could that be NASA?
But aren't they a commercial satellite launch company?

In all seriousness, it does seem that NASA has strayed a little from what their
charter was originally intended to provide.  Perhaps a manned space station is a
good thing to have, but its sole purpose should be technical innovation and research
and development.  Not Economic development.

Mike Kirby
Xerox Corp
E-mail: [e-mail]

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

Date: Tue, 29 Dec 1992 01:17:35 GMT
From: Paul Dietz <[e-mail]>
Subject: Justification for the Space Program
Newsgroups: sci.space,talk.politics.space

In article <[e-mail]> Dr. Norman J. LaFave <[e-mail]> writes:

> My arguement has the benefit of centuries of historical precedent
> which is more than your "There will never be benefits worth the
> expense" arguement you are spouting which can be
> easily argued against using the same historical
> information. Can I prove my assertion?
> No. However, neither can you prove the contrary.


Let me try this again: your historical argument is just bullshit.  The
reasoning is vacuous, independent of the truth of the conclusion.
There are too many differences between then and now to accept the
argument as anything more than sloganeering.  For example: (1) the
vessels they used to explore were straightforward extensions of known
technology, (2) the lands explored did not involve significant
differences in technology in order to survive [those that did, like
the high Artic, were left largely alone for centuries], (3) the
resources they found could be exploited at low cost and yet returned
benefits large in proportion to the size of their economies.  These
conditions don't appear to apply to space.

The track record so far in space is that some limited automated
applications are useful, or profitable (comsats are profitable, at
least for the moment; the others are government-run, so we don't know
if they really would be profitable.)  Space resources?  We went
to the moon and found... very little of practical value.  Space
manufacturing?  Endlessly hyped with little to show for it.
Microgravity research?  Impartial scientific review says it isn't
worth much.

You advance the straw man argument that I am arguing that there will
never be any benefits.  As you say, we can't know that.  But lack of
certainty doesn't mean we are absolved from the need to make decisions
on how scarce funds are expended.  You can't just say "you can't prove
me wrong, so gimme."  At least, not with a straight face.

    Paul F. Dietz
    [e-mail]

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

Date: 29 Dec 1992 02:07:12 GMT
From: Randall Tyers <[e-mail]>
Subject: Justification for the Space Program
Newsgroups: alt.rush-limbaugh,talk.politics.space,sci.space

In article <[e-mail]> [e-mail] (Gary
Coffman) writes:
[...]
>
>Large scale imports from space face a dire problem in any event. What
>are we going to do with all that extra mass? Earth's gravitational
>field will so increase that no one will be able to stand if we bring
>in too much from space. Ultimately we have no choice but to use and
>reuse the materials here on Earth. Fortunately that is getting easier
>and easier as technology advances.
>
>Gary

If this was a joke (it has to be right?? doesn't it?) you should have
indicated this in some manner. (eg. :-) or ;-) )  As your statement
stands it raises doubts about your comprehension of very basic
physics.

A table tells me that the mass of the earth is ~6x10^22 tons!  If I
recall corectly the formula for the strength of a gravitational field is
g=GMe/Re^2 where e stands for earth thus the surface gravity of the
planet increases in direct proportion to its mass ie g is proportional
to M.

Thus to get a 1% increase in g you would need to increase the mass of
the earth by 1% or 6x10^20 tons.  This would be a rather ambitious
project :-) and a 1% increase in g probably wouldn't be a major problem
anyway.

Randall Tyers

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

Date: 29 Dec 92 00:29:05 GMT
From: John McCarthy <[e-mail]>
Subject: Justification for the Space Program
Newsgroups: alt.rush-limbaugh,talk.politics.space,sci.space

Let me add to the previous post the estimate that the total amount of
matter humanity has processed in its history is less than 10^12 tons.
--
John McCarthy, Computer Science Department, Stanford, CA 94305
*
He who refuses to do arithmetic is doomed to talk nonsense.

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

Date: Mon, 28 Dec 1992 21:13:31 GMT
From: Steve Jenkins <[e-mail]>
Subject: Manhattan DISTRICT (not Pr......)
Newsgroups: sci.space

As long as we're being pedantic, the name was

    Manhattan Engineering District.

Nothing whatever hinges on the name. Everyone knows exactly what
the term "Manhattan Project" denotes.

--
Steve Jenkins                  [e-mail]
Caltech/Jet Propulsion Laboratory    [phone]

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

Date: Tue, 29 Dec 1992 03:27:15 GMT
From: Henry Spencer <[e-mail]>
Subject: satellite costs etc.
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Gary Coffman) writes:
>>...assumption, not a self-evident fact.  Communications networks
>>normally have redundancy to cover predictable single-point failures.
>>Even today's gold-plated satellite networks do, despite the expense.
>
>It's the network reconfiguration costs that get you. When NBC had to
>reconfigure from K2 to SBS 3 due to a control failure on K2, it cost
>NBC $150,000 a *minute* for 4.5 hours until the major ground systems
>were re-aimed...   Doing it *unscheduled* because of
>a failure of the cheapsat, can be really expensive if it only happens
>once.

Why do you assume that the redundancy will involve repointing?  If you
*plan* for such handovers, you can put the spare satellite in the same
orbital slot as the operational one.  (Those slots are over a thousand
kilometers wide, there's plenty of room.)  Result, no repointing.  Only
the control room needs to even *know* which bird is live.

>>>... and since for most orbits
>>>the satellites aren't retrievable or repairable, and DC won't change
>>>that...
>>Again, your assumption, not a self-evident fact.  Cheap launches change
>>almost everything, including the feasibility of retrieval and repair.
>
>I wasn't aware that DC was planned to have a GEO capability, or a large
>enough cargo bay to retrieve a major comsat.

Why do you assume that DC alone has to do everything?  The big expense
of doing most anything in space is getting into LEO; cutting that cost
massively makes *everything* more feasible.  It becomes much more
attractive to develop a tug capable of bringing things back down from
GEO, or a reentry capsule capable of landing a payload too big for a
DC cargo bay.  Neither of these devices is technologically difficult;
they don't exist at the moment because operations costs -- mostly
the cost of launching to LEO -- are too high.
--
"God willing... we shall return."       | Henry Spencer @ U of Toronto Zoology
       -Gene Cernan, the Moon, Dec 1972 |  [e-mail]  utzoo!henry

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

Date: Mon, 28 Dec 92 23:03:35 EST
From: John Roberts <[e-mail]>
Subject: Shuttle costs vs DC costs

-From: [e-mail] (Allen W. Sherzer)
-Subject: Re: Stupid Shut Cost arguements (was Re: Terminal Velocity
-Date: 28 Dec 92 15:46:24 GMT

-In article <[e-mail]> [e-mail] (Brian Stuart Thorn) writes:
->  You seem to have two sets of measuring systems at work. One which you
->  use for DC, Titan, Delta et al, and one which you use for Shuttle.

-I disagree; I feel I am working very hard to account for both the same
-way.

-However, if you disagree, please post your own numbers. State the rules
-you want to use and apply to both systems fairly. Then show that Shuttle
-is better.

I tend to agree with you, but you keep factoring initial development cost
into cost of using the Shuttle. While that may be interesting in itself,
it's not really relevant to the question of whether DC should be developed.
The cost of developing DC *is* relevant.

As I said before, it's not a "level playing field", but that's the goal DC
has to meet - development costs plus operational costs of DC, versus just
the operational costs (including any *future* development costs) of the
Shuttle.

If it wasn't felt that this is possible, nobody would be working on DC.

John Roberts
[e-mail]

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

Date: Mon, 28 Dec 1992 22:35:35 GMT
From: Donald Lindsay <[e-mail]>
Subject: Stupid Shut Cost arguements
Newsgroups: sci.space

[e-mail] (Allen W. Sherzer) writes:
>Can you name a product ever made by a successful company which DIDN'T
>keep track of product development costs (as opposed to pure research)
>and assign those costs to the product? Outside government, you won't.

Hmmm. I remember hearing that Xerox bought SDS for a billion dollars
- this would be about 1970. I heard later that Xerox had paid about
twice what it was worth. Apparently SDS had been taking R&D costs and
writing them into the books as assets, ie as if it had purchased
capital equipment with the money.
--
Don        D.C.Lindsay    Carnegie Mellon Computer Science

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

Date: Mon, 28 Dec 92 21:38:08 PST
From: Brian Stuart Thorn <[e-mail]>
Subject: Stupid Shut Cost arguements (was Re: Terminal Velocity
Newsgroups: sci.space

>However, if you disagree, please post your own numbers. State the rules
>you want to use and apply to both systems fairly. Then show that Shuttle
>is better.
>
>I await your reply.
>
>  allen

   Now I'm totally confused, Allen. Wasn't this discussion about the
   Shuttle's launch rate? I thought that you previously belittled a
   25% increase in launch rate, to which I took exception. It was this
   dual-scale measuring (one for Shuttle, one for the others) that I
   am complaining about. I'm still waiting for your explanation as to
   why 25% is a good increase for one, but not another.

   And by the way, I don't seem to be alone in the opinion that 12 per
   year is a more likely maximum safe launch rate. That's a 50% increase.
   Hopefully, the next few months will prove that they can launch
   monthly if they wanted and politics permitted.

   In any case, since Shuttle is the only U.S. system flying that can take
   people to and from space, and is the only system presently capable
   of returning 30,000+ lbs. of cargo, it is very difficult to compare
   Shuttle with the expendables (although I think it compares favorably
   to Titan IV in terms of annual costs versus annual launch rate.) All
   ratings show Shuttle to be the most powerful launch system in the
   free world. Depending upon whom you ask, it's either alot more capable
   than Titan, or just a little.

   Only the DC is presently envisioned to have more or less the same
   attributes as Shuttle, and we both know there is no way Shuttle can
   ever compare favorably to a paper launch system. Pegasus was new and
   revolutionary too, and it has spent the past eighteen months sitting
   in an assembly plant. TSS was new and revolutionary, but was brought
   to its knees by a mislocated bolt. Titan IV was a relatively low-level
   expansion of current technology, but was a year late off the pad and
   has flown at a rate one-fourth of the proposed schedule. GD did a
   relatively minor design change on the Centaur to accomodate greater
   payload, and it has since failed in flight twice. Shuttle has had all
   these problems, and more. Gary and I say similar bugs will afflict
   the DC program, but you tell us not to worry and then call us
   pessimists. Hmph.

   -Brian

   P.S., Sorry about the multiple posts of my previous message in this
   thread. PortalX crapped out on me in the middle of message uploading.

-------------------------------------------------------------------------
Brian S. Thorn                                    "If ignorance is bliss,
[e-mail]                               this must be heaven."
                                                -Diane Chambers, "Cheers"
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End of Space Digest Volume 15 : Issue 606
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