Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT_ZIP/spacedig/V16_2/V16NO299.ZIP/V16NO299

Internet Message Format | 1993-07-13 | 30KB

Date: Thu, 11 Mar 93 05:00:04
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V16 #299
To: Space Digest Readers
Precedence: bulk


Space Digest                Thu, 11 Mar 93       Volume 16 : Issue 299

Today's Topics:
                  Earth Moon anim under X11 (2 msgs)
      Gift to Aliens (was Re: Pluto Fast Flyby post-flyby fate)
                               Huygens
                     Lunar Ice Transport (2 msgs)
                           Mars exploration
                   Pluto Fast Flyby post-flyby fate
    Road & Track road tests 1996 JPL Rocky IV Microrover (2 msgs)
                      Rocket Propulsion (3 msgs)
                          Sodium in exhaust
        Soviet Energia: Available for Commercial Use? (2 msgs)
           SSF Resupply (Was Re: Nobody cares about Fred?)
         Student Design Project (was Re: Lunar Ice Transport)
                             Tether power
                       The courage of anonymity

    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: 10 Mar 93 06:10:00 GMT
From: Michael Nolan <[e-mail]>
Subject: Earth Moon anim under X11
Newsgroups: sci.astro,sci.space

In article <[e-mail]> (Uwe Schuerkamp) writes:
>
>I installed th xanim package (Version 2.29) and tried to get it to run
>the emconj.flc from ames.arc... Xanim barfs with something like...
>
>Next question: What is this xanim.Z at ames:/pub/SPACE/SOFTWARE
>supposed to be? A compressed tar file? Any help would be greatly
>appreciated.

The xanim.Z is a compressed sun/sparc executable.  I put it there
because I thought some people might like to run it without installing
the package, but that information got lost in translation.  You need
xanim rev 2.29.7, which is not trivial to find, lots of sites have old
versions.  I tried archie on xanim229, and all of the ones I tried were
old.

The correct version of xanim is available as
sunsite.unc.edu:/pub/multimedia/utilities/xanim.tar.Z

and I will send it to Ron Baalke, but I can't get in to ames.arc.nasa.gov
right now, so that might take a little while.

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

Date: 10 Mar 1993 17:55 UT
From: Ron Baalke <[e-mail]>
Subject: Earth Moon anim under X11
Newsgroups: sci.astro,sci.space

In article <[e-mail]>, [e-mail] (Michael Nolan) writes...
>In article <[e-mail]> (Uwe Schuerkamp) writes:
>>
>>I installed th xanim package (Version 2.29) and tried to get it to run
>>the emconj.flc from ames.arc... Xanim barfs with something like...
>>
>>Next question: What is this xanim.Z at ames:/pub/SPACE/SOFTWARE
>>supposed to be? A compressed tar file? Any help would be greatly
>>appreciated.
>
>The correct version of xanim is available as
>sunsite.unc.edu:/pub/multimedia/utilities/xanim.tar.Z
>
>and I will send it to Ron Baalke, but I can't get in to ames.arc.nasa.gov
>right now, so that might take a little while.

The most recent version of xanim is now in the /pub/SPACE/SOFTWARE
directory at Ames.
     ___    _____     ___
    /_ /|  /____/ \  /_ /|     Ron Baalke         | [e-mail]
    | | | |  __ \ /| | | |     Jet Propulsion Lab |
 ___| | | | |__) |/  | | |__   M/S 525-3684 Telos | It's kind of fun to do
/___| | | |  ___/    | |/__ /| Pasadena, CA 91109 | the impossible.
|_____|/  |_|/       |_____|/                     | Walt Disney

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

Date: 10 Mar 93 04:02:05 GMT
From: Bill Higgins-- Beam Jockey <[e-mail]>
Subject: Gift to Aliens (was Re: Pluto Fast Flyby post-flyby fate)
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (FRANK NEY) writes:
[on sending a SETI message along on the Pluto Fast Flyby probes]
>
> 300 grams, huh?  I think we can fit in a CD-ROM and instructions for
> that kind of weight.
>
> Only 1/2 B-) here:  I think this might really be a worthwhile project,
> especially if some of us on the outside can put up some bucks and
> volunteeer time.
>
> Who's with me?

There remains the problem of what to put on the CD-ROM.  How about a
few hundred K of Usenet postings discussing the PFF mission?  I think
I can dig them out of the archives...

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: 10 Mar 93 11:59:59 GMT
From: "R.D.Lorenz" <[e-mail]>
Subject: Huygens
Newsgroups: sci.space

Will Huygens float (continued)

As far as I know, all solids likely to be abundant on outer
planet satellites will sink in an ethane ocean. 'Fluffy' material
that could retain some 'air' might well float - I am sure there is
some intersting physics (solubity, surface tension etc) to be done
here. (Optical evidence, and modelling and experiments indicate that
the aerosols that make the atmosphere opaque at visible wavelengths
as seen from space, suggests that the haze particles may have a
fractal geometry - maybe this is efficient at trapping air?)

Whether the imager is immersed or not depends on whether you
prefer pictures of the sea surface and sky, or a murky undersea
picture (probably v. dark - especially if the ocean is aerosol-
laden)

Models suggest noontime illumination at the surface of Titan of
about 10% of the solar flux. This approximates to 100x full moonlight
on Earth.

Note that the experiments to determine ocean composition (if we do
indeed land in an ocean) WANT to be immersed - these experiments
are near the base of the probe. The DISR is on the top half.
Note also that the antenna should be near vertical, to maximise the
probability of keeping the radio link open (the antenna beamwidth
is wide, but finite)

Impact speed, on a small drogue parachute for stability, is 5m/s.
You get this by dropping something from a height of 1m on Earth (very
handy for my impact force experiments!)
If we hit something hard, though, the probe may well not survive.

The probe does not include buoyancy tanks, but does contain a lot of
light foam, for thermal insulation.

There is a radar altimeter, for sequencing experiment operations only
(not a science instrument itself)

The payload comprises
DISR - optical/IR camera and spectrometer (plus lots of other stuff
for measuring haze thickness etc.)
GCMS - all-singing all-dancing composition analyser
ACP - Aerosol collector and Pyrolyser
HASI - Huygens Atmospheric Structure Instrument - Acceleration (entry)
temperature, pressure, electrical activity
SSP - surface science package - physical properties of surface
DWE - Doppler Wind Experiment - winds

For some papers on the probe design, see ESA SP-338 (proceedings of the
conference on Titan, Toulouse, France, September 1991). There should
be an up-to-date article on the probe in the Autumn issue of the ESA
bulletin.

Hope this helps.

ralph Lorenz
Unit for Space Sciences
University of Kent, UK

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

Date: Tue, 9 Mar 1993 22:32:46 GMT
From: Uwe Bonnes <[e-mail]>
Subject: Lunar Ice Transport
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Ross  Borden) writes:
|>     In all the Lunar ice transportation proposals that I've seen,
|> nobody has mentioned what would be, on Earth, the most obvious: overland
|> hauling.
|>     To maintain high through-put, a continuous stream of vehicles
|> would haul ice from the polar ice mines to the equatorial processing
|> plants, and then dead-head back (unless there was some return cargo.)
|>     The trucks would be big.  A standard tractor pulls a trailer
|> with a cargo area 8'x8'x40'-60', plus that again with a super-B.  The

more stuff deleted

???? is this sci.fiction???

Uwe Bonnes  [e-mail]

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

Date: 10 Mar 93 10:18:25 GMT
From: J DARRINGTON <[e-mail]>
Subject: Lunar Ice Transport
Newsgroups: sci.space

Ross  Borden ([e-mail]) wrote:
:     In all the Lunar ice transportation proposals that I've seen,
: nobody has mentioned what would be, on Earth, the most obvious: overland
: hauling.
:     To maintain high through-put, a continuous stream of vehicles
: would haul ice from the polar ice mines to the equatorial processing
: plants, and then dead-head back (unless there was some return cargo.)

Sorry, but I must have missed out on the lead up to this thread - why do
we want to put/move ice on the moon??????

Bemused but fascinated.

Jon.

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

Date: 10 Mar 93 16:25:24 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Mars exploration
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Nick Szabo) writes:
>[e-mail] (Gary Coffman) writes:
>
>>In 1969 no one had even heard of VR telepresence. We still don't do it
>>very well. One of the larger problems even today is dealing with the
>>time lag for feedback. Round trip speed of light time to the Moon is
>>on the order of 2.5 seconds, it's over 4 minutes round trip to Mars
>>at closest approach. Decoupling your movement commands with your
>>perceptions by such a temporal displacement makes a mockery of
>>telepresence.
>
>In some ways yes, in some ways no.  Check out the MIT Press
>journal _Prescence_, especially the paper in the first volume on
>"teleprogramming".  A good VR simulations is combined with a
>modicum of on-site knowledge of the near-term environment, and
>a good error-notification and correction protocol between the
>user and the telebot.  This is mostly being tested for 3-10 sec. delays,
>which are typically for oil industry undersea sonar telepresence, but
>similar principles can be used for longer delays.

The problem is that you run out of the knowledge area of the simulation
faster than you can communicate new data when the distances stretch to
light minutes, or the terrain is rough and your sight lines are short.
This in turn means you operate extremely slowly and reaction to an
unpredicted slip or subsidence will be minutes too late to prevent disaster.
Rather than VR telepresence, you are reduced to pre-programmed move and
wait strategies with at least semi-autonomous disaster avoidance on board
the remote system. This is much less flexible and robust than telepresence
in near real time.

>>A combination of the ever mythical AI
>
>You never cease to attack strawmen, do you?  (a) techniques
>associated with AI, such as robots, expert systems, neural
>nets, etc. are a thriving $multi-billion commercial industry,
>not "mythical", and (b) there is nothing about telepresence
>that requires theoretical breakthrough; it's primarily a matter
>of software hacking and improving hardware thruput.

The limitations of rule based systems and neural networks of
sufficient complexity to deal with unexpected occurances are
extreme. Nothing approaching the AI capabilities promised by
AI researchers 30 years ago has yet been developed. Now some
researchers are saying it'll be here in 30 more years. Where
have we heard this before?

There is indeed nothing about telepresence that requires
theoretical breakthrus, for short delay times, but when
the delays start to exceed a couple of seconds, or the
environment of the remote is unstructured or complex, then
reality rears it's ugly head. Ordinary response time has
to be stretched inordinately, and emergency response is
impossible except by autonomous on board systems. And those
are always "30 years away".

>>VR
>>telepresence seems unlikely to play a major role in forthcoming
>>missions.
>
>You'll have to let astronaut Pete Conrad know, so he can
>stop developing his VR telepilot system for DC-X.

Glad to, "Pete, forget it, it's a rathole for cubic money when you
exceed radio controlled model airplane ranges."

Gary

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

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

Date: 10 Mar 93 13:21:24 GMT
From: FRANK NEY <tnc!m0102>
Subject: Pluto Fast Flyby post-flyby fate
Newsgroups: sci.space

300 grams, huh?  I think we can fit in a CD-ROM and instructions for
that kind of weight.

Only 1/2 B-) here:  I think this might really be a worthwhile project,
especially if some of us on the outside can put up some bucks and
volunteeer time.

Who's with me?

Frank Ney N4ZHG EMT-A  LPVa NRA ILA GOA CCRTKBA "M-O-U-S-E"
----------------------------------------------------------------
If you don't think women explode, try dropping one!
--
The Next Challenge - Public Access Unix in Northern Va. - Washington D.C.
703-803-0391 To log in for trial and account info.

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

Date: 10 Mar 93 16:10:36 GMT
From: "Simon E. Booth" <[e-mail]>
Subject: Road & Track road tests 1996 JPL Rocky IV Microrover
Newsgroups: sci.space

In article <[e-mail]> [e-mail] ("S.K. Whiteman") writes:
>For anyone who in interested the April 1993 issue of Road & Track
>contains a road test of the Microrover. Some of the stats:
>
>Price as tested: $2,500,000
>Top speed        0.037 MPH
>0 to 0.037 mph  like right now
>1/4 mile        24,139.0 sec
>
>All-in-all the article is not as tongue in cheek as one might
>expect.

I thought it was interesting.  BTW Road & Track does something like this
every April (an April Fool's joke).  Ususally though it's been something
that's not even remotely related to cars.  A couple of years ago they
had road test of (no joke!!) a dogsled.

Actually, the rover article covered alot of technical ground in a serious
manner, but I still got some laughs out of seeing automotive terminology
applied to the rover.

I never realized the rover was so small though!
:-)

Simon

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

Date: Wed, 10 Mar 1993 16:32:08 GMT
From: Bruce Dunn <[e-mail]>
Subject: Road & Track road tests 1996 JPL Rocky IV Microrover
Newsgroups: sci.space

> S.K. Whiteman writes:
> For anyone who in interested the April 1993 issue of Road & Track
> contains a road test of the Microrover. Some of the stats:
>
> Price as tested: $2,500,000
> Top speed        0.037 MPH
> 0 to 0.037 mph  like right now
> 1/4 mile        24,139.0 sec
>
> All-in-all the article is not as tongue in cheek as one might
> expect.
>


        Road and Track has being doing these oddball "roadtests" for years.
One year they tested the Goodyear blimp.  I think that best one was the issue
in which the front cover of the magazine promised a road test of a "Mercedes
18 liter GT".  It turned out that the vehicle was from the Mercedes
commercial truck division, and that "GT" stood for "Garbage Truck".



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

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

Date: Wed, 10 Mar 1993 13:23:31 GMT
From: "John S. Neff" <[e-mail]>
Subject: Rocket Propulsion
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Tim Thompson) writes:
>From: [e-mail] (Tim Thompson)
>Subject: Re: Rocket Propulsion
>Date: 10 Mar 1993 05:31:11 GMT
>In article [e-mail], [e-mail] (Gibson Lam) writes:
>>     I am a student doing a research project on Goddard, the man who first
>> invented rocket propulsion.  Of all the eventual uses that rocket
>> propulsion made possible, such as war missiles or the space shuttle, does
>> anyone think that Goddard should be responsible for the eventual uses of
>> his invention?  I would also appretiate any information that you could
>> give me on Goddard or rocket propulsion.
>
>   Do you mean by "responsible", something like "since rockets were made into
>weapons of war, It's all Goddard's fault". Or perhaps "Thank Goddard for space
>flight"? No, I don't think Goddard should be responsible. With precious few
>exceptions, how can any inventor anticipate the use/misuse to which his/her
>inventions will be put?
>
>---
>ALL OPINIONS ARE MINE! ALL MINE !!!! HOWEVER, YOU ARE WELCOME TO SHARE THEM.
>------------------------------------------------------------
>Timothy J. Thompson, Earth and Space Sciences Division, JPL.
>Assistant Administrator, Division Science Computing Network.
>Secretary, Los Angeles Astronomical Society.
>Member, BOD, Mount Wilson Observatory Association.
>
>INTERnet/BITnet:    [e-mail]
>NSI/DECnet:         jplsc8::tim
>SCREAMnet:          YO!! TIM!!
>GPSnet:             118:10:22.85 W by 34:11:58.27 N
>
Rockets were invented by the Chinese and were used in the War of 1812
by the Brits. Remember the "Rockets Red Glare" in our natioal anthem.
These were solid fueled rockets(i.e. tubes full of gunpower) not liquid
fueled rockets that Goddard developed.

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

Date: 10 Mar 93 16:28:59 GMT
From: Henry Spencer <[e-mail]>
Subject: Rocket Propulsion
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Gibson Lam) writes:
>    I am a student doing a research project on Goddard, the man who first
>invented rocket propulsion...

The first thing you need to do is find out what Goddard actually did. :-)
He invented the liquid-fueled rocket, not the rocket.

>anyone think that Goddard should be responsible for the eventual uses of
>his invention? ...

Since *all* technology has military applications, it's really pretty silly
to blame an inventor because the military found a way to use his work.
(Or to call a technology evil because it was developed by the military --
you *do* know who developed the techniques for mass production of
antibiotics, don't you?)

Do we blame the Wright Brothers for Hiroshima?
--
C++ is the best example of second-system| Henry Spencer @ U of Toronto Zoology
effect since OS/360.                    |  [e-mail]  utzoo!henry

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

Date: 10 Mar 93 17:10:06 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Rocket Propulsion
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Gibson Lam) writes:
>    I am a student doing a research project on Goddard, the man who first
>invented rocket propulsion.  Of all the eventual uses that rocket
>propulsion made possible, such as war missiles or the space shuttle, does
>anyone think that Goddard should be responsible for the eventual uses of
>his invention?  I would also appretiate any information that you could
>give me on Goddard or rocket propulsion.

Ahem, Goddard didn't invent rocket propulsion, some Chinese guy about
2,000 years ago did. Goddard was one of several early twentieth century
experimenters working with *liquid fueled* rockets with the intent of
achieving extra-atmospheric flight. The Chinese used rockets in war
many centuries before Goddard was born. The British used war rockets
to bombard Fort McHenry on September 13, 1814 which is where the phrase
"the rocket's red glare" in the Star Spangled Banner comes from. For more
information, see Rocket in any Encyclopedia.

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

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

Date: 10 Mar 93 12:00:55 GMT
From: "R.D.Lorenz" <[e-mail]>
Subject: Sodium in exhaust
Newsgroups: sci.space

Sodium contaminants in rocket exhaust?

Does anyone have any information/references on the presence
of sodium in rocket exhaust (either solid or liquid)

I can understand that the binder, the Ammonium Perchlorate,
or the aluminium in a solid rocket motor could be contaminated
with sodium, but I have never seen any data on this ?

Also, is there any reason sodium compounds might be a contaminant
of dinitrogen tetroxide or nitric acid oxidisers, or hydrazine-
based fuels ?

Please respond by email ([e-mail]) as I don't often read news.

Thanks
Ralph Lorenz

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

Date: 10 Mar 93 16:31:30 GMT
From: "Simon E. Booth" <[e-mail]>
Subject: Soviet Energia: Available for Commercial Use?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Pat) writes:
>
>Problem with energiya, is there is alimited test base for the rocket.
>it hasn't gone through a full qualification program.
>
>Some of the big Com Sat proposals could use a big ELV,  and a lot
>of other programs could use something like it,  but it needs to be demonstrated


My question is how would payloads be mated to an Energia?  The Buran shuttle

This seems cumbersome, unless perhaps the module itself is designed to function
as some sort of unmanned orbiter rather than simply a launch shroud.


One last comment- A while back I read an article in Omni written by, and
along with the article was a rough design for a Mars spacecraft.
This hypothetical craft was desgined for launch by an Energia.

Direct-ascent interplantary flight?

Interesting concept!

(now if we could only get that with a DC-variant- no need for the Energia!)

Simon

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

Date: 10 Mar 93 16:42:47 GMT
From: "Simon E. Booth" <[e-mail]>
Subject: Soviet Energia: Available for Commercial Use?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Simon E. Booth) writes:
>In article <[e-mail]> [e-mail] (Pat) writes:
>
>Problem with energiya, is there is alimited test base for the rocket.
>it hasn't gone through a full qualification program.
>
>Some of the big Com Sat proposals could use a big ELV,  and a lot
>of other programs could use something like it,  but it needs to be demonstrated


My question is how would payloads be mated to an Energia?  The Buran shuttle
is of course attached the same way the US shuttle is mated to its fuel tank,
but I recall seeing an illustration of Energia just prior to its first
flight in early 1988 (minus Buran of course). This diagram showed a
payload module attached to where a shuttle would normally be positioned.

This seems cumbersome, unless perhaps the module itself is designed to function
as some sort of unmanned orbiter rather than simply a launch shroud.

BTW- are we to assume that Energia evolved out of the N-1?

Unless I'm mistaken, N-1 was supposed to exceed the launch thrust of the
Saturn V, something like 9 or 10 million pounds of thrust vs. the Saturn's
7.5 million.

One last comment- A while back I read an article in Omni written by, and
along with the article was a rough design for a Mars spacecraft.
This hypothetical craft was desgined for launch by an Energia.

Direct-ascent interplantary flight?

Interesting concept!

(now if we could only get that with a DC-variant- no need for the Energia!)
:-)

Simon

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

Date: Wed, 10 Mar 1993 16:42:07 GMT
From: Greg Moore <[e-mail]>
Subject: SSF Resupply (Was Re: Nobody cares about Fred?)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Allen W. Sherzer) writes:
>In article <[e-mail]> [e-mail] (Gary Coffman) writes:
>
>>>has shown that Freedom can be built on schedule for $2B per year *IF*
>>>all the money where spent on Freedom.
>
>>>Now this is what they have been getting from Congress for the past
>>>few years and are likely to get for the next few years. If the money
>>>where spent wisely we would have a station.
>
>>Back to the chart:
>
>The chart isn't relevant. Average the money received over the past
>three years (including this year) and you get a sum very close to
>what NASA says is needed. Include next years funding and it goes over
>the top.
>
    Oh, come on Allen, you know better than that.  Tell you what,
I need to hire you for 3 years.  The salary is $60,000 a year.  Well,
that's what it averages too.  The first year I'm only going to pay
you $10,000 a year.  The second year maybe I'll pay you $20,000.

The final year I'll pay you the rest.

Can you life on this?  Can you make the ends meet?
Avereging over the years doesn't work.

>For the next ten years $2B per year IS an achieveable figure and would
>allow NASA to build the station *IF* they would spend the money on
>Freedom. I note that you don't seem to be bothered that NASA, by its
>own estimates, is wasting upwards of a third of the funds allocated.
>
>   Allen
>
>--
>+---------------------------------------------------------------------------+
>| Allen W. Sherzer | "A great man is one who does nothing but leaves        |
>|  [e-mail]     |  nothing undone"                                       |
>+----------------------102 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

Date: 10 Mar 93 03:58:02 GMT
From: Bill Higgins-- Beam Jockey <[e-mail]>
Subject: Student Design Project (was Re: Lunar Ice Transport)
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (J DARRINGTON) writes:
> Ross  Borden ([e-mail]) wrote:
> :     In all the Lunar ice transportation proposals that I've seen,
> : nobody has mentioned what would be, on Earth, the most obvious: overland
> : hauling.
> Sorry, but I must have missed out on the lead up to this thread - why do
> we want to put/move ice on the moon??????

You did.  A professor at the University of Cincinnati has assigned a
design project to a bunch of engineering students.  Several of the
students have been asking sci.space readers for advice.

The project's assumptions include:

1. A source of water ice at the poles of the Moon.
[This is scientifically plausible; evidence does not yet rule it out.]

2. It must be moved to a lunar base at the lunar equator for
processing into rocket propellant (and perhaps other useful
products?). [This is completely senseless; obviously the processing
should be done at the poles, near the "ice mines."]

Since the object of the game is to teach young designers to work to a
customer's specifications, I see nothing inherently wrong with
assumption 2.  It's a shame, though, that their scenario isn't more
realistic; if it were, they could present their results at technical
conferences.

Okay, Cincinnati, did I get it right?

P.S. If your professor can offer some good reason why assumption 2 is
*not* dumb, the Net would like to hear from him or her!

--
     O~~*           /_) ' / /   /_/ '  ,   ,  ' ,_  _           \|/
   - ~ -~~~~~~~~~~~/_) / / /   / / / (_) (_) / / / _\~~~~~~~~~~~zap!
 /       \                          (_) (_)                    / | \
 |       |     Bill Higgins   Fermi National Accelerator Laboratory
 \       /     Bitnet:     [e-mail]
   -   -       Internet:  [e-mail]
     ~         SPAN/Hepnet:      43011::HIGGINS

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

Date: Wed, 10 Mar 1993 14:57:46 GMT
From: Zach K <[e-mail]>
Subject: Tether power
Newsgroups: sci.space

[e-mail] (Josh Hopkins) writes:

>[e-mail] (Frank Crary) writes:

>>Using a tether to generate power actually increases the need for
>>reboosts: The current creates an IxB force (essentially an
>>electromagnetic drag) which slows the station.

>This is of course true.  However, if you replace the solar arrays with a tether
>you are also eliminating a large source of drag.  I would presume that the
>net drag still increases, but has anyone actually done the calculations to
>show it?
I have not done the calculations but I would think It would be better
to use solar for power and the tether to maintain the orbit.

Zach

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

Date: 10 Mar 93 16:44:18 GMT
From: Melinda Shore <[e-mail]>
Subject: The courage of anonymity
Newsgroups: comp.org.eff.talk,sci.space,alt.privacy

In article <[e-mail]> Nicholas Kramer <[e-mail]> writes:
> And I ask you: How many people here give different weight to ideas on
>Usenet based on the author?

I do, often.  Over the years you come to know that certain
people know what they're talking about, while others are
monomaniacal crackpots.

It seems obvious to me that anonymity is often a good
thing, especially in areas where people do have something
valid to say but have legitimate reasons to fear the
consequences if their identity is known (and yes, it does
happen).  The problem, though, is less one of authority
than it is responsibility.  People who dissasociate their
identities from their postings no longer need to be as
responsible, and the results of that are the kinds of
content-free flamers that show up, for example, in the
gay-related newsgroups.  This is a problem that I'd very
much like to see go away - nobody should post unless
they're willing and able to take responsibility for the
contents of their articles.  Period.
--
       Melinda Shore - Cornell Theory Center - [e-mail]

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

End of Space Digest Volume 16 : Issue 299
------------------------------