Message-ID: <Yb4KGVG00VcJMDh05U@andrew.cmu.edu>
Precedence: junk
Reply-To: space+@Andrew.CMU.EDU
From: space-request+@Andrew.CMU.EDU
To: space+@Andrew.CMU.EDU
Date: Tue,  9 Oct 1990 01:48:18 -0400 (EDT)
Subject: SPACE Digest V12 #434

SPACE Digest                                     Volume 12 : Issue 434

Today's Topics:
		     Frame sequential TV in space
		    Re: Magellan Update - 10/03/90
	    Re: Cost comparison: Apollo/Saturn vs. Shuttle
			       Re: quit
	   Re: You Can't Expect a Space Station to be Cheap
	    Re: Cost comparison: Apollo/Saturn vs. Shuttle

Administrivia:

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

Date: 8 Oct 90 17:00:52 GMT
From: snorkelwacker!usc!wuarchive!zaphod.mps.ohio-state.edu!uakari.primate.wisc.edu!uflorida!mailer.cc.fsu.edu!sun13!gw.scri.fsu.edu!pepke@tut.cis.ohio-state.edu  (Eric Pepke)
Subject: Frame sequential TV in space

I saw some TV pictures from the Shuttle on CNN last night, and when there 
was much motion, the image left behind colored ghost images.  This leads 
me to believe that it is essentially a frame-sequential system.

If so, why is such a system used?  I know that NTSC is notoriously phase 
sensitive, but surely in this digital age we don't need to be limited by 
that.  Are the reasons historical?

Eric Pepke                                    INTERNET: pepke@gw.scri.fsu.edu
Supercomputer Computations Research Institute MFENET:   pepke@fsu
Florida State University                      SPAN:     scri::pepke
Tallahassee, FL 32306-4052                    BITNET:   pepke@fsu

Disclaimer: My employers seldom even LISTEN to my opinions.
Meta-disclaimer: Any society that needs disclaimers has too many lawyers.

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

Date: 8 Oct 90 03:11:08 GMT
From: fernwood!portal!cup.portal.com!PLS@decwrl.dec.com  (Paul L Schauble)
Subject: Re: Magellan Update - 10/03/90

Now that raises an interesting question...

If you pointed the Hubble at Mars, could it get a better picture of the "fact"
than we now have?

  ++PLS

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

Date: Mon, 8 Oct 90 13:13:34 -0400
From: "Allen W. Sherzer" <aws@iti.org>
Subject: Re: Cost comparison: Apollo/Saturn vs. Shuttle
Newsgroups: sci.space
Cc: 

In article <39582@eerie.acsu.Buffalo.EDU> Craig Cole writes:
>>The Soviets launch on expendables, and they return payloads and people
>>from space all the time...

>What I meant to say was that the shuttle can return MUCH larger and
>heavier payloads from orbit than expendables.

What laws of physics prevent one from building a return capsule of
any size? 

>Really, the expendable itself doesn't return anything from orbit - the
>payload itself does. 

Fine. The fact remains that expendables are a key part of a system
which can return items at far less cost than the Shuttle.

>Granted, Solar Max and Syncom didn't require the shuttle, only a
>"man-on-the-scene," but other satellites did. (I can't remember their
>names.) 

Those satellites where recovered an highly subsidized rates. It would
have been cheaper to buy new ones. But this begs the question. If we
had a reasonable infastructure and satellites designed to operate in
that infastructure, there would have been no need to return them either.
They could have been fixed/refueled in orbit.

>Nothing other than the shuttle could return those payloads.

Unproven.

>Launching from the shuttle is no bargain, but I bet recovery is.

Also unproven. 

>Designing an aeroshell and recovery chutes for a payload already
>in space would cost quite a bit of time and money.

Doesn't sound too expensive to me. How much did an Apollo capsule
cost?

  Allen
-- 
+-------------------------------------------------------------------------+
| Allen W. Sherzer      |         What should man do but dare?            |
|   aws@iti.org         |             - Sir Gawain                        |
+-------------------------------------------------------------------------+

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

Date: 7 Oct 90 19:24:00 GMT
From: sgi!cdp!nec@ucbvax.Berkeley.EDU
Subject: Re: quit


Yes:     You can find info undoubtedly from space camp!
         You can get their address and Ph.# from this
         conference topic# 12(9-29-90).
         Good Luck!
         Chow.................................
                                [DRon G.

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

Date: 2 Oct 90 19:18:27 GMT
From: convex!convex.convex.com!ewright@uunet.uu.net  (Edward V. Wright)
Subject: Re: You Can't Expect a Space Station to be Cheap

In <1990Sep24.205408.6972@eagle.lerc.nasa.gov> dbm0000@DOMAIN_2.lerc.nasa.gov (Dave McKissock) writes:

>The following was recently distributed by the LeRC Public Affairs
>Office. It is an excerpt from a "Letter to the Editor" in the
>New York Times. Although it's a trifle old (published 6/26/90),
>I think the points raised by the author (J. Grey, Director,
>Science & Technology Policy, AIAA) are still relevant...

>You Can't Expect A Space Station to Be Cheap


>For example, you quote me saying, "We've spent $4 billon so far
>and there isn't a nut or bolt" - of flight hardware - "to show
>for it." But you don't add my reason: four years of filling requests
>for reviewing, reevaluating, rescoping, justifying and redesigning
>the station haven't given NASA the chance to get on with designing
>and building it.

In other words, government bureaucracy makes it impossible for
government bureaucrats to anything on schedule or within budget.
This is a surprise?


>Your headling is another example of serious (but typical) distortion.
>The "120 billion" includes the $81 billion estimated for 30 years
>of operations, not just the cost of designing, developing, building
>and assembling the station, which is what the original "$8 billion"
>of the headline would have bought. 

Let's see, $81 billion to operate an 8-man space station for 30 years.
That's more than $300 million per man-year of operation.  As Robert
Heinlein said, an elephant is a mouse built to government specifications.


>More important, however, to present a one-sided case against the
>station, you do not even bother to mention the primary finding of 
>that Research Council study, that none of the alternative space-station
>configurations examined by the committee was judged to be as 
>satisfactory as the Block I, NASA-designed configuration. 

So what about alternatives that the National Research Council
*didn't* consider?


>Another example: you cite the "25 billion program" to develop the
>space shuttle. Again, either you mix development and operational
>costs to make a one-sided point 

So?  Every commercial aircraft manufacturer has to consider both 
"development and operational costs" or go out of business. Why is
it legitimate for NASA to pretend that development costs don't exist?


>or fail to include 18 years of 
>inflation. The shuttle's development was funded at $5.22 billion in
>1972 dollars, with a Congress-mandated overrun limit of 20 percent.
>Despire all its problems, it came in within that limit.

Rubbish.  The Shuttle is *still* "under development."

>Nobody expects the space station to be cheap. Our overseas partners
>have committed almost $8 billion to their roles in its development
>and assembly. 

Let's not mention that the last time NASA built a space station, with
Skylab, it took less than four years and about $1 billion to do it. Or
that we could build the equivalent using just one Space Shuttle external
tank today.  Or that Lawrence Livermore National Labs has devised far
less costly space stations based on inflatible structures.  Or that NASA
itself designed 50-man space stations, less than 20 years ago, that could
be built for less than the cost of the 8-man station proposed today....

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

Date: 9 Oct 90 03:32:05 GMT
From: uceng!dmocsny@iuvax.cs.indiana.edu  (daniel mocsny)
Subject: Re: Cost comparison: Apollo/Saturn vs. Shuttle

In article <9010081713.AA18333@iti.org> aws@ITI.ORG ("Allen W. Sherzer") writes:
>What laws of physics prevent one from building a return capsule of
>any size? 

1. The depth of the atmosphere?

2. Tidal forces exceeding the strength of material?

3. Requiring the capsule to "land" on the planet? (Instead of having
the planet "land" on the capsule?)

4. The onset of nuclear fusion at the capsule's core?

5. The appearance of an event horizon?

6. The mass of the Universe? (That is probably a pretty solid upper
bound on capsule size, assuming the Universe is closed.)

Actually, perhaps an upper bound on capsule size would occur at
some fairly small level, say a hundred million tons, thanks to
the square-cube law. At some mass, the capsule would not be able
to maintain its integrity during aerobraking if it were too big.
The only way to keep it together would be to reduce its surface
area, preventing it from losing enough speed before hitting
the ground. Small asteroids (1 km dia.) don't lose much speed
before hitting the ground. If you parked one in LEO, you'd have
to let it down in pieces.

Here is a question for would-be space miners: if you had a nice
Ni-Fe asteroid parked in LEO and you wanted to bring down, say,
500,000 tons of it per year, would you be better off:

1. Quarrying out bits of it and sending them down in reusable
re-entry vehicles;

2. Fabricating one-shot re-entry vehicles mostly out of asteroid metal
and loading them with mined ore;

or 3. (My favorite) Blasting out large chunks of ore in the
correct shape to serve as re-entry vehicles, and dropping them
down onto a piece of deserted land or shallow water? (Obviously,
you wouldn't want to be around during "deliveries".)

Also, what would be the likely effect on the space-junk situation
of hacking up an asteroid in LEO? (Heh heh.)


dmocsny@uceng.uc.edu

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

End of SPACE Digest V12 #434
*******************