Space & Astronomy/Space and Astronomy (October 1993).iso/pc/text/spacedig/v15_6/v15no617.txt

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Date: Thu, 31 Dec 92 05:25:42
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V15 #617
To: Space Digest Readers
Precedence: bulk


Space Digest                Thu, 31 Dec 92       Volume 15 : Issue 617

Today's Topics:
                       *** BUSSARD RAMSCOOP ***
                       Aluminum as rocket fuel?
                       Comparative $/lb to LEO
                          Dante Advisory #3
                GEO satellites as electrical vehicles
                   Justification for Space Program
                         Latest Pegasus news?
                          Moon Dust For Sale
                         satellite costs etc.
                       Saturn lift capabilities
                              Sea floor
                        Space List Flame Wars
                       SSTO vs 2 stage (2 msgs)
    Stupid Shut Cost arguements (was Re: Terminal Velocity of DCX?

    Welcome to the Space Digest!!  Please send your messages to
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----------------------------------------------------------------------

Date: 31 Dec 92 03:19:04 GMT
From: Miles Abernathy <[e-mail]>
Subject: *** BUSSARD RAMSCOOP ***
Newsgroups: sci.space

I don't know exactly how you will get the hydrogen to fuse in the ramjet.
So far that problem remains unsolved here on Earth, except for fusion
reactions catalyzed by atomic explosions.
= = = = = = = = = = = = = = = = = = = =
  _     Miles Abernathy, N5KOB        =
 | |__  [e-mail]       =
_|    | POB 7580, Austin TX 78713     =
\  * /  University of Texas @ Austin  =
  \/    tel. [phone]           =
= = = = = = = = = = = = = = = = = = = =

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

Date: Thu, 31 Dec 1992 03:00:52 GMT
From: Bruce Dunn <[e-mail]>
Subject: Aluminum as rocket fuel?
Newsgroups: sci.space

> Nick Janow writes:
>
> What are the problems with using molten aluminum sprayed into the reaction
> area?  Keeping the aluminum molten in a vacuum should be relatively easy.



        This I like!  Molten aluminum (melting point 660 C) can be kept in
steel tanks.  Using molten aluminum will give a higher Isp than aluminum
metal.  Major problems will be pumping, and how to keep the aluminum from
freezing in pipes and injectors when the motor is shut off.  The idea is not
as crazy as it sounds.  Liquid lithium (melting point 181 C) has already been
fired in motors (use liquid fluorine as an oxidant, with and without the
addition of hydrogen to raise the specific impulse).


--
Bruce Dunn    Vancouver, Canada   [e-mail]

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

Date: Wed, 30 Dec 92 22:36:18 EST
From: John Roberts <[e-mail]>
Subject: Comparative $/lb to LEO

-From: [e-mail] (Edward V. Wright)
-Subject: Re: Comparative $/lb to LEO (Was: Stupid Shuttle Cost Arguments)
-Date: 29 Dec 92 17:11:40 GMT
-Organization: Engineering, CONVEX Computer Corp., Richardson, Tx., USA

-That said, there are some launchers that cost more, per pound
-of payload on orbit, than the Shuttle.  But they are very small
-launchers that don't have many pounds of payload to spread
-their cost across.

Well said. The Shuttle has some good points, but cost isn't one of them.

The advantages of the small, high $/lb launchers are low cost for a
dedicated launch, and reducing the time spent waiting for a launch
(at least in theory - Pegasus has to increase its launch rate if it
wants to serve that market).

If DC is successful, the small launchers may have to adjust their market
niche (or their prices).

John Roberts
[e-mail]

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

Date: 31 Dec 92 02:30:00 GMT
From: Ron Baalke <[e-mail]>
Subject: Dante Advisory #3
Newsgroups: sci.space,alt.sci.planetary,comp.robotics,sci.geo.geology

Charles Redmond
Goddard Space Flight Center
Greenbelt, Md.                        Dec. 30, 1992
(Phone:  [phone])

DANTE ADVISORY #3

ROBOT POISED AND READY FOR DESCENT INTO VOLCANO

        The 8-legged rappelling robot Dante was being placed into
position at the rim of the Antarctic volcano Mt. Erebus late
on December 30 in preparation for its descent down the steep
slopes on Thursday, Dec. 31.  Dave Lavery, the Erebus
project manager, said from the Antarctic that the team
expected the robot to be actively descending the 70 degree
slopes of the inner rim of the volcano by early morning on
Thursday.

        NASA will provide a live video feed of the Dante robot
activities, including the first live transmission from the
robot's onboard television camera system, beginning at 8:15
am EST and continuing through 9:00 am.

        The live video will continue later Thursday with
live feeds showing the robot's point of view as it navigates
slowly down the steep slope of the volcano.  Thursday video
feed times have been set for 12:35 through 1:25 pm EST,
2:10 pm through 3:40 pm, 3:42 pm through 3:57 pm,
4:20 pm through 5:25 pm, 5:50 pm through 6:10 pm, and
7:25 pm through 8:25 pm.  All of this video will be available on
the NASA Select satellite as it is received by the communications
support team at the Goddard Space Flight Center.

        During the 8:15 am through 9:00 am EST video period, Dave
Lavery and possibly other members of the combined NASA-
National Science Foundation-university team at the volcano
will provide a live audio commentary of the activity.  The
video feeds are being transmitted from a remote NASA
Tracking and Data Relay Satellite portable station set up on
the ice at the team's base hut, several thousand feet below
the volcano rim.  The audio portion will be transmitted
through a communications link through the INMARSAT
satellite.

        NASA will also provide a commentary from participating
robotic and geophysical science team members during the
Antarctic video feeds beginning at 12:35 pm EST.  The audio
commentary will originate from robotic specialists from
Carnegie-Mellon University, who built the $2 million robot
system for NASA, and from NASA Goddard scientists involved
in the geochemical and geophysical science investigations
which the robot will perform once it reaches the floor of
the crater.

        A similar video support schedule at approximately the same
Eastern Standard times is being developed for Friday and
Saturday.  If all goes according to current plans, Dante is
to spend Friday exploring the lava lake in the crater floor
of Mt. Erebus to provide geophysical and atmospheric
chemistry data about the volcano's outgassing and the
composition of the lava lake.  The team expects to have
Dante begin its climb back up to the rim on Saturday, but
that could be delayed by science observations until Sunday.

PROJECT IS DEVELOPING FUTURE EXPLORATION CAPABILITIES

        NASA and the National Science Foundation are undertaking
this demonstration project to develop technology and
telecommunications capabilities which NASA could use in
future explorations of the Moon or Mars and which the NSF
might apply to its ongoing research activities in the
Antarctic.  Part of the test involves transferring control
of the robot from the Mt. Erebus team to team members
located at a payload control center at Goddard.  This
portion of the project will test the "telepresence"
capabilities of such robots for future NASA exploration
missions and could occur during Friday or Saturday's lava
lake exploration phase.

        Carnegie-Mellon University and the New Mexico Institute of
Mining and Technology are partners with NASA and the NSF as
robotics and volcano experimenters for this project.

        The following paragraphs have been abstracted from the
message stream which Dave Lavery has been providing to the
Carnegie-Mellon staff and other associates of the project who are
located in a temporary payload operations control room at
the Goddard Space Flight Center.  These messages have been
sent via the TDRS satellite from computers in the Erebus project
tent on the slope of Mt. Erebus and received by the POCC computers
at Goddard.  It is from this POCC that Jim Osborn, CMU Erebus
project manager and four other CMU
robotics experts will perform the remote control test to
simulate "telepresence" activities.  These messages are
abstracted from the past two days and cover the period from
December 29 through 30 (Eastern) and 31(Antarctic Time):

****The following message posted by Erebus project manager
Dave Lavery on Dec. 29 (local Antarctic time, which is EST
plus 17 hours) describes the crater of Mt. Erebus:

"At the rim, the outer crater is about 750 feet across.
Approaching from the ascent path, the slope is about 45
degrees which nearly levels off to a twenty-foot side shelf
at the edge of the crater itself.  The crater slopes away at
a 60-degree angle very quickly, with a very short transition
area, for about 100 feet.

"From there on down to the lava lake is a combination of 60-
to 90-degree slopes strewn with boulders and ice towers
ranging from one to four feet in size.  About 700 feet down
inside the crater is a very large fumarole that has recently
appeared which is pounding out gases like an old steam
engine which is right in line with the descent route and may
become a primary target for gas sampling.

"The crater itself was fairly clear of gases most of the
time that I was at the rim, and I had direct visibility down
into the inner crater. The gases and steam from the crater
are coming from the lava lake itself and from the fumarole
fields, most of which are on the far side of the crater wall

from our worksite.

"The consistency of the outer cone material is fairly poor.
It is made up of a combination of desiccated lava bombs and
rock crystals which are all very loosely bound together by
crushed lava and ice.  Most of the exposed surfaces are then
covered with a thin layer of sulfur deposited from the
crater (which gives everything this weird green fuzzy
appearance!)."

****The following message posted by Erebus project manager
Dave Lavery on Dec. 30 (local Antarctic time, which is EST
plus 17 hours) describes the finishing activities of placing
the robot Dante and its carrier Geryon in place at the
crater rim:

"Geryon, with Dante aboard, had been pulled to within 600
meters of the Erebus
crater rim when work was stopped this morning at 1:00 am
local time.  We anticipate that it will require four more
winch pulls by Geryon to attain the crater rim.  Each winch
pull involves driving two or three anchors into the ice with
sledgehammers (each anchor is a five-foot length of  2-1/2
inch diameter steel pipe), running out up to 200 meters of
winch cable from the winch on Geryon to the anchors, slowly
winching in to the anchor point, then repeating the process.

"The only problem we have really had so far is that we are
running short of sledgehammers.  The handles become
relatively brittle in the cold, and they keep breaking.

"We have received a question about the composition of the
group currently at the Lower Erebus Hut (located about 1500
feet below and 1-1/2 miles from the crater rim).

"Currently at the camp are: Red Whittaker (Carnegie-Mellon
University, director of the CMU Field Robotics Center and
chief project scientist); Eric Hoffman (CMU/K2T, designer of
the Dante mechanism); Dan Christian (CMU, software
specialist); Dave Wettergreen (CMU, software specialist);
Dave Lavery (NASA, Telerobotics Program Manager,
communications and videography); Phil Kyle (New Mexico
Institute of Mining and Technology, principal research
scientist and Mt. Erebus expert);  Sara Krall (Antarctic
Support Associates, camp director and cook); Ken Sims
(Antarctic Support Associates, mountaineer); and Steve
Thompson (NASA/GSFC, TDRSS communications specialist).

"Also helping out  are Nelia Dunbar (NMIMT, volcanology
researcher) and Bill Macintosh (NMIMT, volcanology
researcher).  Bill and Nelia are here working under a
separate grant doing their own research, but have been
assisting the project quite a bit when manpower and Erebus
expertise are needed.;

****The following message posted by Erebus project manager
Dave Lavery on Dec. 31 (local Antarctic time, which is EST
plus 17 hours) describes their accomplishment of the outer
rim ascent and preparations for the robot descent:

"As of 1800 hours, Geryon and Dante have completed the
ascent of the outer cone of Mt. Erebus.  Once Geryon was
aligned with the "launch point" for Dante's descent into the
volcano crater, it was anchored in place.  Fittings and
equipment for the final outfitting of the robot were then
moved up to the launch point and stored for the evening.

"The final activity for the day was running the fiber optic
cable from Geryon's position down the mountain to the Lower
Erebus Hut to the operator control station.  This involved
spooling out the fiber optic cable approximately 2
kilometers to the hut, and then verifying the communications
over the fiber.  As of 2300, the video and audio signals
from Dante on the rim were being received at the control
stations, and the communications to the robot appears to be
fully operational.

"The plans for Dante's closeout tomorrow morning include
assembling and installing the sensor mast (including the
trinocular video system, the laser scanner and the
teleoperated camera), completing the installation of the
science package, validating the fiber optic communications,
and final sealing of all enclosures.  After that, Dante will
stand up off Geryon, Geryon will be removed, and Dante will
squat down on the ground in preparation for "launching."
When ready, Dante will be manually positioned at the
transition point into the crater and slid over the lip of
the crater rim.  The onboard and remote control systems will
then take over and the robot will stand and begin the
descent into the crater.

"This afternoon's ascent included my second trip up to the
rim of the crater. The crater interior was much calmer today
than during my last trip a few days ago.  The cyclonic winds
emanating from the crater were more sedate, with what seemed
like about half of the velocity of the previous visit.

"The plume from the lava lake itself was much milder, with
clear visibility down to the inner crater.  Occasional puffs
of steam reached as high as the outer crater rim, but rarely
went above that.  Without the intense plume activity of the
other day, and the milder winds, we were able to spend about
three hours at the rim without too much trouble.  The rim of
the crater is covered with a combination of crystallized
lava and lava bombs.  The lava bombs are ejected
periodically by the lava lake during eruptions, and vary in
size from a few inches to several feet across.  They are
primarily composed of lava glass, and weather away fairly
quickly.  Within a year or two, they are almost completely
disintegrated.  When they are completely decomposed by
weathering, they leave behind lava crystals which were
embedded in the bomb.  The crystals are anywhere up to three
inches or so in length, and are all over the place.  They
are pretty neat, but actually make for fairly precarious
footing as they tend to slide over each other when stepped
upon."

****End of this set of messages****
     ___    _____     ___
    /_ /|  /____/ \  /_ /|     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: 31 Dec 92 01:00:09 GMT
From: Gary Coffman <ke4zv!gary>
Subject: GEO satellites as electrical vehicles
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Bruce Dunn) writes:
>Regarding Geosynchronous satellites launched from a DC-1
>
>        An interesting idea.  Modern comsats have several kilowatts of power,
>enough to run an ion or arcjet engine.  An electric engine running off a few
>kilowatts has a mass of only a few kg, so could easily be carried on the
>vehicle.  The same ion engine could be used for station keeping - all that
>would be required is a larger propellant supply to allow for return to LEO.
>A major problem would probably be radiation damage due to having to spend
>some months in the Van Allen belts as the satellite spirals down to LEO.
>This damages solar cells, but if the array is replacable, this might not be
>too bad.  Other electronics might have to be replaced because of radiation
>damage, but during servicing it might be desirable to replace them anyway for
>updating and extension of service life.

After you discard the solar cells and electronics, what do you have left
but some aluminum framing and a bit of plumbing? It hardly seems worth the
bother when you consider that you've lost the use of the system for several
months. Transponder time is $400 an hour. For a 24 transponder bird, a
downtime of 3 months equals $20.7 million in lost revenue. You still have
to produce most of the expensive satellite system replacement parts, do an
LEO launch, EVA servicing requiring major systems overhaul, and reinsertion
into Clarke orbit. Can you do all that for $20.7 million less than just
launching a whole new bird with a newly fabricated aluminum frame?

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     |                     | emory!ke4zv![e-mail]

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

Date: 31 Dec 92 01:19:14 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Justification for Space Program
Newsgroups: sci.space

In article <[e-mail]> [e-mail] writes:
>Reasons for Space Program: Well maybe with the technology provided by the Space
>Rpogram we can better predict the future climatic changes and more and help
>Somalia and other places to stop being such a pain on the resources.. Not to
>say Somalia deserved what they have, but with out some major changes of their
>culture or atleast basic ideas of agriculture and more, they will be back where
>they are in a few years. Remember Ethipia next door, it was less than 15 years
>since they had the same problems that Somalia has..

Somalia's problems aren't climatic. They've had periodic droughts
throughout history. Their problem is political. Ethiopia is the same,
a Marxist government that decayed into civil war and anarchy.
The local culture was tuned to this drought cycle in both nations,
but it was disrupted by Marxism and the resulting decay of the
nation into war and chaos. Space offers no solutions to these
political problems.

>Maybe the Space Program is expensive, but is that becuase they are not doing
>anything or is that because of poor management? I believe the benefits they
>provide are benefitial toa ll, including Somalia.. Maybe the Shuttle is to many
>things and can't get any done wuite right, well maybe we need to change our
>expectations and build more specific space vehicles..

Space is expensive because of the one G field and air resistance we
fight to get from being stationary on the ground to travelling 17,000+
miles an hour 200 miles up. Travelling 200 miles, even straight up,
isn't that energy intensive, but doing that while accelerating to
orbital speed in atmosphere is very energy intensive, and energy,
especially compact lightweight energy, isn't cheap, nor is the equipment
needed to harness it.

Sure NASA is inefficient, as is any government endeavor, but the problem
is simply hard, and will remain so until some radically different method
of reaching orbit is developed.

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     |                     | emory!ke4zv![e-mail]

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

Date: 31 Dec 92 00:45:13 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Latest Pegasus news?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Allen W. Sherzer) writes:
>In article <[e-mail]> [e-mail] (Gary Coffman) writes:
>
>>And to think, it was only last year that Pegasus was the net's darling
>>that was going to bring the cost of space travel down to nil.
>
>I think you will be very hard pressed to find anybody who thought
>Pegasus was going to bring the cost of space travel to nil. That wasn't
>its goal.
>
>>bandwagons are not only crowded, they also seem to be short lived. It's
>>funny that the flaws only show up when something actually flies.
>
>We may all be thankful that the people at OSC are willing to try things
>to see if they will work. Left to you, nobody would ever try anything
>since everything which doesn't exist today, in your view, can't be done
>and won't work. Progress is never made by pesismist.

You misrepresent my position. All I'm saying is that new systems are
rarely as cheap and easy in metal as they are on paper. That's what
research and development programs are designed to discover. Only a few
things that pass through development ever reach mass production as
cheap and troublefree as they were on paper.

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     |                     | emory!ke4zv![e-mail]

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

Date: Thu, 31 Dec 1992 00:35:16 GMT
From: Mike Marolda <[e-mail]>
Subject: Moon Dust For Sale
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Ron Baalke) writes:
>Superior Galleries in Beverly Hills, California is having an auction
>of space memorabilia on January 11, 1993.  One item of particular interest
>is a 2 inch piece of transparent tape which has some Moon dust on it.  This is
>the first time that Moon dust is being offered for sale.   The Moon dust
>was collected by a NASA technician from the spacesuit of astronaut Dave Scott
>after his Apollo 15 trip to the Moon in July, 1971.  It is guarantteed
>to be genuine by Superior Galleries and is expected to be sold
>in the price range of $75,000 to $100,000.  For more information on the
>Moon dust or the auction, you can contact Superior Galleries at
>[phone] or [phone].

The ironic (and sad) thing is that by bidding, one is gambling that we will
never return to the moon and that the value will increase due to the scarcity
of the product.


Mike Marolda  ([e-mail])


--

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

Date: 31 Dec 92 00:41:06 GMT
From: Gary Coffman <ke4zv!gary>
Subject: satellite costs etc.
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Allen W. Sherzer) writes:
>In article <[e-mail]> [e-mail] (Gary Coffman) writes:
>
>>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 always limit your thinking so Gary? First of all, the DC-Y
>payload bay is almost the same size as Atlas. A production DC would have
>a payload bay of whatever size the market needs. Second of all, you aren't
>thinking of how lower costs will affect operations. Maybe a modified
>DC-1 is used as an OTV to get payloads where they are returned to LEO for
>repair (and not brought back to Earth). Maybe you use lower costs to fly
>redundant satellites, each less relaible. When one breaks, it uses a
>high efficiency electric engine to come back to LEO where it is repaired,
>refueled, and returned. Maybe we abandon comsats in GEO and place them in
>LEO. I can think of lots of alternatives.

I can too, but they all cost money and require developments beyond
a simple SSTO to LEO. Without costing them out, including them in
SSTO mission cost profiles against more conventional systems is bogus.
Without costing them out, there is no assurance at all that they will
lower systems costs. It's like saying that a Pinto is cheaper to develop,
buy, and operate than a unit train so we should deliver coal to power
plants in the trunks of millions of Pintos.

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     |                     | emory!ke4zv![e-mail]

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

Date: 31 Dec 92 03:17:46 GMT
From: Henry Spencer <[e-mail]>
Subject: Saturn lift capabilities
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Dave Michelson) writes:
>Although items such as food and clothing could have been replenished
>rather easily, I'm under the impression that oxygen and nitrogen could
>not.  Skylab was essentially designed as a "throw-away" workshop...

Basically correct.  Resupply undoubtedly could have been done, if you
were willing to work hard enough, but Skylab wasn't really designed
for it.  Actually, even food and clothing were mostly pre-stocked aboard
Skylab, because the Apollo CSM as flown for Skylab did not have a very
large payload capacity.  The biggest difference between Skylab and Mir
is that Skylab lacked any equivalent of the Progress unmanned freighters.

Skylab would also have needed substantial repairs for long-term use;
things were failing, like its momentum wheels.

It would have been fairly straightforward to fly one or two more crews,
but keeping it habitable in the long term would have been harder.  Even
when NASA was planning to reboost Skylab on an early shuttle mission,
there weren't any very specific plans to use it again.
--
"God willing... we shall return."       | Henry Spencer @ U of Toronto Zoology
       -Gene Cernan, the Moon, Dec 1972 |  [e-mail]  utzoo!henry

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

Date: Wed, 30 Dec 92 22:23:03 EST
From: John Roberts <[e-mail]>
Subject: Sea floor

-From: [e-mail] (Josh Diamond)
-Subject: Re: Justification for the Space Program
-Date: 30 Dec 92 16:01:58 GMT
-Organization: Bear, Stearns & Co. - FAST

-Did it ever occur to anyone out there to consider the environmental
-impact of large scale disruption of the sea floor?  I could result in
-severe problems with algal blooms and plankton die-offs, with effects
-all the way up the food chain...

You're right that any extensive mining of the sea floor will have to take
environmental concerns into account.

Another problem - there are many organisms in the sea floor material (dormant
or in spore form) that are otherwise extinct. Bringing the bottom ooze to the
surface could possibly revive the populations of some of these organisms.
And it's not necessarily guaranteed that the predators that formerly kept
these populations under control are still around.

I'm not attempting to evaluate the level of risk, but it's something that
should be considered.

It would probably be a good idea to be careful with the first couple of
subsurface Mars samples returned to Earth, on similar grounds.

By the way, before I forget - I recently saw an old (1960s) clip on NASA
Select, discussing the sterilization of unmanned probes for exploration of
planetary surfaces (so as to avoid contaminating possible native life before
studies could be conducted). The plan at that time was to sterilize the
probes by exposing them to ethylene oxide gas. Items such as sensors that
might be sensitive to ethylene oxide could be sterilized by other means,
and covered during exposure to the gas.

John Roberts
[e-mail]

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

Date: Wed, 30 Dec 92 22:06:36 EST
From: John Roberts <[e-mail]>
Subject: Space List Flame Wars

-From: [e-mail]
-Newsgroups: sci.space
-Subject: Space List Flame Wars
-Date: 30 Dec 92 17:06:42 GMT

-I subscribed to this list in order to try to inform myself about the latest
-news about US and other coutnries' space programs.  I thought that this would
-be a list of technical discussions, not a religious debate that has turned
-into ad hominem attacks and flame wars as virulent as any I've seen in the
-religious news groups.

-Such political ranting belongs in the alt.talk.politics or alt.religion
-groups.  Could we please take them out of the space list?

Amen!

-In addition, there is much too much signal to noise ratio in the flame wars
-and the ad hominem attacks.  Could we move them out of the list and into
-private emails?  There is too much heat and not enough light coming out
-of them.

There are at least four problems with some of the current posts:
 1) Being unnecessarily nasty. Obviously, nobody who's still participating
    in the debates is going to be swayed by heat alone. (It brings to
    mind the Eddorians in the Lensman series - they gave up fighting one
    another only when they realized that all the Eddorians that were left
    were too tough to be killed.)
 2) The attitude of "I could come up with a good argument to counter your
    claims, but you're too stupid to appreciate it, so I'll save the effort
    and post a poor argument instead". There are some awfully poor arguments
    being used to support otherwise good points, and of course this attitude
    is self-perpetuating.
 3) Arguing at cross-purposes. Sometimes both participants have good
    arguments, but they're aiming at different topics, so the debate never
    comes to a resolution, and confusion results.
 4) Arguments in which all the participants basically agree with one another -
    they just haven't noticed it yet. :-) These usually degenerate into
    recriminations over who said what and when they said it - and the variable
    delay of the net adds fuel to the fire.

-I know that I have now left myself wide open to being attacked from all
-sides, but I just thought that, considering the size of the mailings that I'm
-getting, there is too much of this stuff to wade through to get to anything
-worth reading.

More important - some of us are too busy wading through the flames to get
around to posting as much worthwhile stuff as we would like to.

Don't despair - flame wars are usually cyclic. There are often long intervals
with very few flames.

John Roberts
[e-mail]

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

Date: Thu, 31 Dec 1992 03:30:01 GMT
From: Bruce Dunn <[e-mail]>
Subject: SSTO vs 2 stage
Newsgroups: sci.space

> Retarding SSTO, Edward V. Wright writes:
>
> Advances in technology, perhaps, but hardly recent advances.  The old
> Saturn S-IVB stage could've been turned into a SSTO launcher, with a
> payload the size of a Gemini spacecraft.  The "unattainable mass ratio"
> is nothing more than an aerospace legend.
>


        This somewhat confuses the issue, in that it tends to imply that the
technology necessary to build a DC-1 was available a generation ago.  The
S-IVB derivative would be a ***non-reusable*** SSTO, which is a different
animal than a ***reusable*** SSTO.   In order to recover your hypothetical
S-IVB vehicle, you will have to add equipment for recovery and landing,
including a retrofire system, heat shielding, parachutes (or the fuel and
throttable engines for a powered descent), landing gear (or waterproofing of
all systems), etc.  The extra mass will kill your payload.

        What is really hard is not making an SSTO, but making a "RRSSTO" or
Recoverable Reusable Single Stage to Orbit which has enough payload to
justify its costs (however accounted for).




--
Bruce Dunn    Vancouver, Canada   [e-mail]

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

Date: Thu, 31 Dec 1992 03:35:22 GMT
From: Bruce Dunn <[e-mail]>
Subject: SSTO vs 2 stage
Newsgroups: sci.space

> Paul Dietz writes:
>
> The mass ratio on an airliner is much less than in a launcher with
> chemical rocket propulsion, for rather fundamental reasons.  It is
> therefore not inconceivable that multistage launchers would be
> appropriate even though multistage aircraft are not.



        If the delta V needed to get to orbit were only 5000 meters per
second rather than the 9000+ meters per second which we have to deal with, we
would never be having this discussion.  No-one would think of building a two
stage rocket.  Clearly, the Earth is no place for a space-faring
civilization.  Time to move to Mars :-)


--
Bruce Dunn    Vancouver, Canada   [e-mail]

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

Date: 31 Dec 92 00:48:31 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Stupid Shut Cost arguements (was Re: Terminal Velocity of DCX?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Allen W. Sherzer) writes:
>In article <[e-mail]> [e-mail] (Gary Coffman) writes:
>
>>In military procurement, the development costs are charged against
>>the prototypes, X, Y, etc, and the operational vehicles of the procurement
>>are charged at "flyaway" cost.
>
>Which I suspect is done largely to hide the true cost. I point out that if
>the contractors in question ran their accounts this way they would all be
>in jail and out of buisness.
>
>>Following this model, Enterprise ate the
>>development costs, and it's retired. Current Orbiters are only liable for
>>their $1.5 billion flyaway cost and their operational costs.
>
>But why should we follow that model? Hiding costs like you advocate only
>encourages waste and inefficiency. How can we possibly make access to space
>cheap if we make it impossible to identify those costs and reduce them?

These costs aren't hidden. They are published and charged to a different
mission, that of R&D. NASA is a R&D operation by charter. Whether the
fruits of that R&D ever flies is a totally separate matter.

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     |                     | emory!ke4zv![e-mail]

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End of Space Digest Volume 15 : Issue 617
------------------------------