HDTenEightyP/NetNews huggingface dataset:
From: ewright@convex.com (Edward V. Wright)
Subject: Re: satellite costs etc.
Date: Tue, 29 Dec 1992 20:06:05 GMT
Organization: Engineering, CONVEX Computer Corp., Richardson, Tx., USA
X-Disclaimer: This message was written by a user at CONVEX Computer
              Corp. The opinions expressed are those of the user and
              not necessarily those of CONVEX.

In <1hfromINN3a5@mirror.digex.com> prb@access.digex.com (Pat) writes:

>Actually, henry.  both of you are sticking to the clarke orbit model.

>Most of the effort in the Telecom industry is oriented towards
>LEO comm sats.  store and forward or multiple fast relay satellittes.

Actually, Pat, just about all (Western) communications satellites,
in terms of numbers and (especially) in terms of dollar value, are 
in GEO.  This may change in the future -- a number of companies are
banking on it -- but it certainly isn't true today.


Newsgroups: sci.space,alt.folklore.urban
From: PAPAI@kcgl1.eng.ohio-state.edu (Jonathan Papai)
Subject: Re: asteroids beyond Jupiter
Organization: The Ohio State University
Date: Sun, 27 Dec 1992 00:54:19 GMT

warren@nysernet.org (Warren Burstein) [and others] ask:
>In <28030@dog.ee.lbl.gov> twcaps@tennyson.lbl.gov (Terry Chan) writes:
>>Whaddaya say?  10.5 Shergolds?  Where is snopes where you need 'im?
>
>I've been wondering about that, too.

rose@cecily.UUCP (Rose M. Delckum) asks:
>     I realize this is off the subject, but what happened to
>Cindy?  (I've been away for a while)
>
>Rose

	Many other regulars (if I may use that term) besides just
Snopes and Cindy seem to be missing since the Pluto/Neptune
thread erupted.  I conjecture that Bill Nelson sent them on a
fact-finding mission to the nether reaches of the solar system to
determine where Pluto originated.

Jon "Feet firmly planted on earth" Papai
From: 0001964967@mcimail.com (Daniel Burstein)
Newsgroups: sci.space
Subject: numerous/ 1:ASAT 2:Water 3:misquotes
Date: 23 Dec 92 15:53:19 GMT
Article-I.D.: cs.Bzpyuw.MIG.1
Distribution: sci
Organization: [via International Space University]
X-Added: Forwarded by Space Digest
Original-Sender: isu@VACATION.VENARI.CS.CMU.EDU

A few points related to recent discussions:

1) ASATS:

  While very few nations have the capability to destroy orbiting 
satellites, countries have another option.  It is relatively
trivial  to "blind" or otherwise disable
an overhead platform.  In simplified terms, just take a few
megawatts of power, hook it up to a radar unit, slide through
a few frequencies, and there go the satellite systems.
   While producing permanent shutdown is tricky, short term 
disruption is simple.

2) Materials from space:

  Some very new research published in "The Sciences" (by the NY
Acad of Science, Jan/Feb 1993, author: Raymond Jeanloz) describes
the possibility that water gets locked into otherwise "dry" rock
when under extreme pressures.  He suggests this hidden water
(in deep Earth) may be ten times the amount in the oceans.

   I'm not familiar enough with his conclusions, or current thoughts
about astro-geology, to state this with any certainty, but
his work would -possibly- suggest that there may be a lot more
water available in extra-terrestrial rocks than currently thought.

   (Could someone "out there" in netland check into this further?)

3) Mis-quotes:

a) Just being a stickler for accuracy here, but if any group should
get this one right, it would be a science-oriented discussion
like this one.  Numerous people have made reference to the
program that developed the first nuclear weapons by the 
United States during World War two.

   Contrary to popular belief, the actual name for this
was the "Manhattan District." (I won't print the wrong one)
                   ^^^^^^^^
b) On a different topic, some people have given the 
wrong attribution to the saying "because it's there."
As per Bartlett's sixteenth edition, p. 593, this quote
was -not- from "EH", but was by George Leigh Mallory, who
used it to explain why he wanted to climb Everest.

Yours in Fussbudgetness...
Danny Burstein

<dburstein@mcimail.com>
From: WHITEMAN%IPFWVM.bitnet@UICVM.UIC.EDU ("S.K. Whiteman")
Newsgroups: sci.space
Subject: Galileo HGA
Date: 28 Dec 92 20:59:01 GMT
Article-I.D.: cs.BzzMBw.EnL.1
Distribution: sci
Organization: [via International Space University]
X-Added: Forwarded by Space Digest
Original-Sender: isu@VACATION.VENARI.CS.CMU.EDU

It seems to me that a lot of energy is being stored in the stuck HGA
ribs; kinda like loading a spring; isn't this going to give the whole
spacecraft quite a jolt when/if they release?
        \       /___________________          Sam
         \_____/                   |          IBM Systems Programmer
Chicago/ |                     *   |  O       Indiana University -
    I    |               Ft. Wayne |  H       Purdue University at Fort Wayne
    L    |               1794-1994 |          Fort Wayne, Indiana USA
Newsgroups: sci.space
From: gene@wucs1.wustl.edu (_Floor_)
Subject: Re: Acceleration
Organization: The K-Zoo Crew
Distribution: sci
Date: Tue, 22 Dec 1992 22:04:05 GMT

In article <BznC82.74x.1@cs.cmu.edu> roberts@cmr.ncsl.nist.gov (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
] acceleration. (For another example, putting rubber feet or a springy internal
] suspension in a piece of equipment can greatly reduce the maximum shock if
] you drop it.)

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.

] 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
] changes can cause very high internal stresses that are not found with slow,
] steady increases in acceleration.
] 
] Just as an example, compare your body lying in a bed with a downward 
] acceleration of one gravity, or being clamped in a device that repeatedly
] shakes your body back and forth, with a maximum acceleration of half a gravity.
] Which do you think would be likely to place more stress on your body, and
] which would be quicker to cause discomfort? :-)
] 
] John Roberts

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 :-)


  _____    "But you can't really call that a dance. It's a walk." - Tony Banks
 /  ___\  ___  __ ___   ___      _____________   gene@cs.wustl.edu
 | / __  / _ \ | /   \ / _ \     |  physics  |   gene@lechter.wustl.edu
 | \_\ \ | __/ |  /\ | | __/     |racquetball|   gev1@cec2.wustl.edu
 \_____/ \___/ |_| |_| \___/     | volleyball|   gene@camps.phy.vanderbilt.edu
 Gene Van Buren, Kzoo Crew(Floor), Washington U. in St. Lou - #1 in Volleyball
Newsgroups: sci.space
From: ewright@convex.com (Edward V. Wright)
Subject: Re: aerospikes
Date: Mon, 21 Dec 1992 18:31:11 GMT
Organization: Engineering, CONVEX Computer Corp., Richardson, Tx., USA
X-Disclaimer: This message was written by a user at CONVEX Computer
              Corp. The opinions expressed are those of the user and
              not necessarily those of CONVEX.

In <BzHGox.9Lx@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes:


>Substantial cross-range is indeed primarily a military requirement,
>driven by the one-orbit mission, whose basic rationale is deploying a
>spy satellite -- or doing any of a number of other things -- in wartime
>conditions where coming around again in a predictable orbit is likely
>to result in being shot at.

Of course, if the enemy has the capability to shoot at you, he also
has the capability to shoot down that nice, new spy satellite, which
is also in a predictable orbit.  It is not clear to me that this
requirement was well thought-out.

Newsgroups: sci.space
From: Bruce_Dunn@mindlink.bc.ca (Bruce Dunn)
Subject: Re: SSTO vs 2 stage
Organization: MIND LINK! - British Columbia, Canada
Date: Thu, 31 Dec 1992 19:54:55 GMT

Regarding my assumption that SSTO proposals based on the Saturn S-IVB would
be non returnable and non-reusable, Henry Spencer writes:

>
> No, some of the S-IVB-based SSTO proposals were reusable.  I don't know
> how well they would have worked, and I don't know that I'd plan a spaceline
> based on them without waiting a while to see how reusable they really were,
> but on paper it was feasible.


        I stand corrected, although somewhat puzzled. If you have the details
handy Henry, could you inform us how it was planned to recover a cylindrical
stage without having it break up the way the Shuttle ET breaks up when it
hits the atmosphere?  Presumably this must involve some mechanism for keeping
the stage oriented and tumble free during re-entry.  What heat shield
materials were planned in this era prior to the Shuttle tiles and blankets?


--
Bruce Dunn    Vancouver, Canada   Bruce_Dunn@mindlink.bc.ca
Newsgroups: sci.space
From: rcs@cs.arizona.edu (Richard Schroeppel)
Subject: Lunar ice
X-Added: Forwarded by Space Digest
Organization: [via International Space University]
Original-Sender: isu@VACATION.VENARI.CS.CMU.EDU
Distribution: sci
Date: Thu, 24 Dec 1992 01:45:52 GMT


I notice the proposed LEI probe doesn't include imaging.
(1) How do they know where the probe is looking when it's taking data?
(2) Since "permanent solar shadow" != "permanent Earth shadow",
    how about looking for ice glints by Earthlight?

Rich Schroeppel  rcs@cs.arizona.edu

Xref: sparky sci.space:18004 talk.politics.space:1570
From: gcoleman@magnus.acs.ohio-state.edu (George Coleman)
Newsgroups: sci.space,talk.politics.space
Subject: Re: Justification for the Space Program
Date: 22 Dec 92 02:33:53 GMT
Distribution: usa, world
Organization: The Ohio State University

>for every dollar spent in space there is an estimated 7 dollar return in
> space spin offs.

I have read this many times in nasa releases and every time it struck a sour
chord.  If there is that much return on technical research than it sounds like
the market is in great demand.  Simple supply and demand would then dictate
that many firms would try to fill this demand.  Call me strange but I trust the
market more than I trust press release from a government agency.  If this were
realy true than there should be a *private* firm raking in a bundle of money.
To save so time and net space I will knock down the obvious straw man...
     The government needs to step in because there is a market failure.
     Technology is a common good and free market doesn't have means to
     provide common goods.....

Maybe, just maybe private firms have a hard time marketing new advances but
with a 7/1 return they should be able to find a way.  Second, if the market
realy can't work the goverment should specialize.  Have one agency specialize 
in product development and one agency build real, working space ships.  NASA 
spends way to much time developing new technology instead of mass producing 
proven designs.
Ed Colmeman
Newsgroups: sci.space
From: Bruce_Dunn@mindlink.bc.ca (Bruce Dunn)
Subject: Titan and Shuttle SRBs
Organization: MIND LINK! - British Columbia, Canada
Date: Sun, 27 Dec 1992 05:36:20 GMT

> Brian Stuart Thorn writes:
>
>    SRMs related to the Shuttle's SRBs? For beginners, the Titan SRM first
>    flew in 1965 (Titan IIIC) while Shuttle SRB did not first fire until
>    1977 and did not fly until 1981. Titan SRMs are manufactured by
>    Lockheed and Aerojet, I think. Shuttle SRBs by Thiokol.
>
>    Even if you are referring to the new 7-segment Titan IV SRMs, still
>    the answer is no. These were designed, but never built, for the
>    MOL program. I believe that if there is any connection, it's vice
>    versa.
>


        Correct - the Shuttle SRBs are derived from experience gained with
the Titan boosters, not the other way around.  From "Advanced Chemical Rocket
Propulsion" by Y.M. Timnat:

        " The high reliability demonstrated by the Titan III solid boosters
was the main reason that NASA decided, after studying the advantages and
disadvantages of solid versus liquid boosters, of parallel and series burning
and of various sizes, to use two solid-propellant boosters having a diameter
of 371 cm, 38.1 m long and containing 502580 kg of propellant, using a
segment configuration with the same [as the Titan] PBAN propellant."

        Both solid boosters use a segmented design, fabricated out of Ladish
D6ac high strength steel.  The thrust vector control however differs: the
Titan uses N2O4 injection into the nozzle to deflect the exhaust, while the
Shuttle boosters have a nozzle whose throat is attached to a flexible collar
which allows the nozzle to be steered by a hydraulic system.






--
Bruce Dunn    Vancouver, Canada   Bruce_Dunn@mindlink.bc.ca
Newsgroups: sci.space
From: henry@zoo.toronto.edu (Henry Spencer)
Subject: Re: Aluminum as rocket fuel?
Date: Thu, 31 Dec 1992 22:58:12 GMT
Organization: U of Toronto Zoology

In article <19070@mindlink.bc.ca> Bruce_Dunn@mindlink.bc.ca (Bruce Dunn) writes:
>... have the molten aluminum stored in a spherical steel
>tank pressurized by injecting liquid nitrogen into the tank (which because of
>the heat will immediately vaporize).  Is nitrogen available from the moon?

There's no significant amount of nitrogen on the Moon unless there are
frozen polar volatiles.  You can recover a very little bit from the
regolith, if you're willing to process a lot of regolith.

A note of caution:  you're assuming that nitrogen is an inert gas.  This
isn't necessarily true when hot metals are involved.  I'm not sure about
aluminum, but I know titanium will burn fiercely in nitrogen (in fact,
the ash from titanium burning in air is about 80% titanium nitride).
Without an ignition source, the combination might be stable enough.
-- 
"God willing... we shall return."       | Henry Spencer @ U of Toronto Zoology
       -Gene Cernan, the Moon, Dec 1972 |  henry@zoo.toronto.edu  utzoo!henry
Newsgroups: sci.space,talk.politics.space
From: rbw3q@rayleigh.mech.Virginia.EDU (Brad Whitehurst)
Subject: Re: Justification for the Space Program
Organization: University of Virginia
Distribution: usa, world
Date: Wed, 23 Dec 1992 14:14:08 GMT

In article <_ft2g9b@rpi.edu> strider@clotho.acm.rpi.edu (Greg Moore) writes:
>In article <1992Dec22.143159.4832@murdoch.acc.Virginia.EDU> rbw3q@rayleigh.mech.Virginia.EDU (Brad Whitehurst) writes:
>>>
>>	Well, Paul, I won't even try to convince you with facts.  We'd
>>still have flat-earthers if somebody hadn't run out to the "edge" and
>>tried jumping off, despite all the great Greek geometry.  
>
>	Actually, before you start blaming the Greeks, keep in mind
>that they had a good idea the earth was curved.  They even developed
>a rough approximation of the diameter based on the shadow of the sun.
>
>	It was a Greek (the name escapes me) that described a
>heliocentric solar system.  Unfortunately Plotemly had better press.
>
	I KNOW IT!!!!  Why do you think I made the allusion?  I'M NOT
BLAMING GREEKS!!!  Alright, for the metaphorically impaired:  Greek
mathematicians (don't remember name..started with "T") showed the
Earth was round and estimated diameter using the relative positions of
shadows at the bottoms of wells.  DESPITE this marvelous scientific
work, the general belief that the world was round did NOT become
accepted until some damn-fool sailors went out and PROVED it.  That
was my whole point...that otherwise perfectly intelligent people hold
to certain views until some daredevil goes out and DEMONSTRATES the
contrary, usually by doing something that everyone tells him will get
him killed!
*Flame off*
	Sorry, but sometimes I despair at getting a net.point across
with any attempt at subtlety or metaphor.  Loosen up a little and
avoid too much literalness! :-)
	Anyway, time to pack the bags and the presents, go tune up the
sleigh, and file some flight plans! :-)***
	Peace on Earth (and off!), and goodwill to all men.

Merry Christmas! 

-- 

Brad Whitehurst    |   Aerospace Research Lab
rbw3q@Virginia.EDU |   We like it hot...and fast.
Newsgroups: sci.space
From: aws@iti.org (Allen W. Sherzer)
Subject: Re: Stupid Shut Cost arguements (was Re: Terminal Velocity
Organization: Evil Geniuses for a Better Tomorrow
Date: Sun, 27 Dec 1992 20:43:10 GMT

In article <72332@cup.portal.com> BrianT@cup.portal.com (Brian Stuart Thorn) writes:

>>Correct. But Shuttle is now flying at or very near its maximum rate.

>   No, I disagree here. NASA has never had four working shuttles in
>   service at the same time 

A few years ago I saw some figures on the amount of overtime needed to
process a Shuttle. It was horendous. Adding more Shuttles will just tax
the groundcrew even more. Adding staff to eliminate this bottleneck will
only increase costs.

>   In 1992, all four orbiters flew twice, but Discovery was offline
>   from February to November, Columbia offline from January to May,
>   and Atlantis offline from August to December. Take away those
>   downtime periods and you can add three more flights. 

Your assuming that orbiter availability is the only bottleneck.

I'm sure they could add one or two flights a year. But so what? all that
means is that instead of spending three times what we need we are 'only'
spending 2.75 times what we need to. I don't consider that much of a
victory.

>   This is all
>   moot, since NASA apparently does not want to push its luck prior
>   to SSF assembly, but it does show that the launch rate is lower
>   than it could be.

No because those are factors. The bottom line is that NASA cannot fly
many more missions per year than they are now.


    Allen

-- 
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "A great man is one who does nothing but leaves        |
|  aws@iti.org     |  nothing undone"                                       |
+----------------------118 DAYS TO FIRST FLIGHT OF DCX----------------------+
Newsgroups: sci.space,sci.physics
From: henry@zoo.toronto.edu (Henry Spencer)
Subject: Re: Breeders
Date: Tue, 22 Dec 1992 23:48:34 GMT
Organization: U of Toronto Zoology

In article <ZOWIE.92Dec22141804@daedalus.stanford.edu> zowie@daedalus.stanford.edu (Craig "Powderkeg" DeForest) writes:
>...In Canada, they don't enrich their uranium at all for
>the CANDU reactors -- by using heavy water as a moderator, they
>improve the fission efficiency to where natural uranium is sufficient.

Actually, not quite true.  The CANDU can burn natural uranium quite
happily, but it's somewhat more efficient with slightly-enriched uranium,
and that's what our CANDU power reactors normally use.  If it became
costly or hard to get, we'd switch.
-- 
"God willing... we shall return."       | Henry Spencer @ U of Toronto Zoology
       -Gene Cernan, the Moon, Dec 1972 |  henry@zoo.toronto.edu  utzoo!henry
Xref: sparky sci.space:18183 talk.politics.space:1596
From: rubinoff@linc.cis.upenn.edu (Robert Rubinoff)
Newsgroups: sci.space,talk.politics.space
Subject: Re: Greek Science (was Re: Justification for the Space Program
Date: 24 Dec 92 15:53:02 GMT
Followup-To: sci.space
Distribution: usa, world
Organization: University of Pennsylvania

In article <phv203p@rpi.edu> strider@clotho.acm.rpi.edu (Greg Moore) writes:
>It's interesting to listen to how people believe that Columbus proved
>the world was round.  Actually, he and most people he argued with didn't debate that point.  His claim was that the earth was about 12,000 miles in diameter.
>Most people believe he was way off and they were right.  

umm...12,000 miles in *circumference*.  The Earth is actually about 8000 miles
in diameter, 24,000 miles in circumference -- just about twice what Columbus
thought.

   Robert
Newsgroups: sci.space
From: roberts@cmr.ncsl.nist.gov (John Roberts)
Newsgroups: sci.space
Subject: Re: ground vs. flight
Date: 26 Dec 92 19:23:45 GMT
Article-I.D.: cs.BzvsK1.LBv.1
Distribution: sci
Organization: National Institute of Standards and Technology formerly National Bureau of Standards
X-Added: Forwarded by Space Digest
Original-Sender: isu@VACATION.VENARI.CS.CMU.EDU


-From: henry@zoo.toronto.edu (Henry Spencer)
-Subject: Re: ground vs. flight
-Date: 24 Dec 92 06:05:43 GMT

-In article <=hv29vp@rpi.edu> strider@clotho.acm.rpi.edu (Greg Moore) writes:
-...
->	Also, given that the bottom of the shuttle is covered with
->tile, can the orbiter exert a Y+ (i.e. vertically up) translation?

-There aren't any RCS nozzles on the orbiter's belly, but both the forward
-and aft RCS systems have nozzles angled down so that they can (somewhat
-inefficiently) thrust upward.

I believe that capability was used extensively during the Intelsat capture
this year.

John Roberts
roberts@cmr.ncsl.nist.gov