HDTenEightyP/NetNews huggingface dataset:
From: henry@zoo.toronto.edu (Henry Spencer)
Subject: Re: ROTATION OF THE MOON
Date: Wed, 18 Nov 1992 18:35:35 GMT
Organization: U of Toronto Zoology

In article <10160@ncrwat.Waterloo.NCR.COM> tjgerman@53iss6.Waterloo.NCR.COM (Trevor German) writes:
>	...rotational speed of the moon. I know it has a rotation time
>	that matches the orbit time but I was wondering why this is ?
>	Is the match exact ?

Yes.  The Earth raises tides in the Moon the same way the Moon raises
tides in the Earth (there are tides in the Earth's crust and atmosphere
as well as in the oceans, although they're less conspicuous).  Having
tidal bulges constantly moving over the surface takes energy, because
there's friction involved in moving that mass around -- be it fluid
flow or flexing rock -- and some energy gets lost as heat.  That energy
has to come from somewhere.  Most any small satellite of a larger body
will rapidly lose rotational energy to tidal drag, and end up rotating
in synchronization with its orbit, so the tidal bulges are "frozen" in
and do not move.  The Moon is not unique in this; a lot of the planetary
moons in the solar system show this locked rotation.

It works both ways too.  Earth's rotation rate is slowing, very slightly,
due to tidal drag from the Moon (and the Sun).  It's taking much longer
than it took for the Moon, because the Earth is much the more massive of
the two.

If you want to see tidal effects in action on a large scale, look at Io.
Its rotation is locked to Jupiter, but it still has tides because its
orbit is slightly elliptical (so the bulges, although fixed in place,
rise and fall as the distance to Jupiter varies).  Tidal drag would have
circularized the orbit long ago, except that Io is locked in a resonance
with the other large moons that draws energy from all of them to keep it
in that orbit.  And so Io *boils* -- it's the tidal friction that keeps
those volcanoes erupting furiously on such a small body, which normally
would have lost all its internal heat long ago.
-- 
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  henry@zoo.toronto.edu  utzoo!henry
Newsgroups: sci.space
From: roberts@cmr.ncsl.nist.gov (John Roberts)
Subject: Re: Space suit research?
X-Added: Forwarded by Space Digest
Organization: National Institute of Standards and Technology formerly National Bureau of Standards
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Distribution: sci
Date: Sat, 21 Nov 1992 03:36:22 GMT


-From: fcrary@ucsu.Colorado.EDU (Frank Crary)
-Subject: Re: Space suit research?
-Date: 20 Nov 92 22:39:24 GMT
-Organization: University of Colorado, Boulder

-I wasn't suggesting enriched oxygen: A 10 psi, 20% oxygen atmosphere
-should be perfectly acceptable. That's less oxygen than at sea level,
-but certainly enough to support people (even physically active people).
-Since there are cities with this sort of partial pressure of oxygen,
-and people, in fact, go there to be physically active (ski), I'd say
-there is considerable evidence that this isn't a health problem.

Apparently anything significantly below 3 psi partial pressure of oxygen
is a potential health risk, unless you have many generations of ancestors
who lived in the mountains. The body undergoes various changes to adapt to
low oxygen content, but some of these changes have undesirable side effects.
I'll try to find that Scientific American article again and post a summary.

John Roberts
roberts@cmr.ncsl.nist.gov
From: sdd@zip.larc.nasa.gov (Steve Derry)
Newsgroups: sci.space
Subject: Re: Mars Observer Update - 11/13/92
Date: 17 Nov 1992 19:15:24 GMT
Organization: NASA Langley Research Center, Hampton, VA  USA
Distribution: world
NNTP-Posting-Host: zip.larc.nasa.gov
Keywords: Mars Observer, JPL

In article <1992Nov13.192046.22718@news.arc.nasa.gov>, baalke@kelvin.jpl.nasa.gov (Ron Baalke) writes:
|> 
|> A new Star Catalog/Ephemeris was uplinked and a successful "USE"
|> command radiated this morning.  The ephemeris previously used had the
|> intended effect of altering the solar array sun incidence angle by 5
|> degrees, from 60 degrees to 55 degrees.  This sun incidence angle periodic
|> decrease will be performed in subsequent ephemeris loads, with the final
|> objective being to point the high-gain antenna at earth by the time
|> transition from inner to outer cruise takes place.  The current offset is
|> designed to prevent direct sunlight on the solar panels creating an excess
|> amount of power.  At the time of transition from inner to outer cruise, the
|> spacecraft will be of sufficient distance from the sun that excess power
|> is of a lesser concern.

I understand why it is undesirable to point the solar array directly at the 
sun at this point in the mission.  But why can't the HGA be pointed at earth?
Aren't the solar array and HGA independedtly steerable?

-- 
Steve Derry
<s.d.derry@larc.nasa.gov>
From: jafoust@cco.caltech.edu (Jeffrey Alan Foust)
Newsgroups: sci.space
Subject: Re: Clinton's address (was Re: Feynmann's legacy)
Date: 21 Nov 1992 22:43:14 GMT
Organization: California Institute of Technology, Pasadena
NNTP-Posting-Host: punisher.caltech.edu

In article <1992Nov21.133516.1@stsci.edu> hathaway@stsci.edu writes:
>
>Thank you - we don't get much in the way of alt. groups here - nor Prodigy.  
>BTW, what was the 4th 'major campaign'?   I heard of a bunch of others that 
>b&m'ed that they weren't being taking seriously, but I didn't take 
>them seriously... <-). 

The Libtertarian candidate, Andre Marrou.  Marrou/Lord, along with 
Clinton/Gore, Bush/Quayle, and Perot/Stockdale, were considered to be "major"
because their names were on the ballot in all fifty states.
-- 
Jeff Foust                        Senior, Geophysics/Planetary Science, Caltech
jafoust@cco.caltech.edu   			   	 jeff@scn1.jpl.nasa.gov
		Tom Seaver: "Hey, Yogi, what time is it?"
		Yogi Berra: "You mean now?"
Newsgroups: sci.space
From: ewright@convex.com (Edward V. Wright)
Subject: Re: Dyson Sphere's (again???)
Date: Fri, 20 Nov 1992 17:22:55 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 <wf2gt=G00VoyMYglpu@andrew.cmu.edu> Maulik Harish Shah <msb0+@andrew.cmu.edu> writes:

>	This had probably been discussed (I caught the tail end of a Dyson
>Sphere thread in the backposts). But:
>	How would you detect a dyson sphere? A true dyson sphere (as far as I
>know) would totally enclose the sphere. And, logically, the Material
>that  you would have to make the dyson sphere out of would have to have
>an enormous tensile strength. 

Well, Dyson himself did not actually propose a solid sphere, which would
require materials that are not only unavailable but unreasonably strong,
given our understanding of physics.  What he invisioned was a large number
of habitats in orbit about a star which, together, would completely encircle
the star in a ball-of-twine formation.  From a distance, it would look like
a solid shell.

A star enclosed by a Dyson sphere (either Dyson's original or the solid 
version, which was invented later by science-fiction writers) would be
invisible at normal wavelengths but would be visible, due to waste heat, 
in the far infrared.  To astronomers, a star enclosed by a Dyson sphere
would appear as an infrared supergiant.  Dyson proposed that we look for 
such stars as a means of finding extraterrestrial intelligence.
From: borden@sol.UVic.CA (Ross Borden)
Newsgroups: sci.space
Subject: shuttle computers
Keywords: publications
Date: 20 Nov 92 20:42:27 GMT
Organization: University of Victoria, Victoria, B.C. CANADA

>In article <Bxwy52.G3o.1@cs.cmu.edu> roberts@cmr.ncsl.nist.gov (John Roberts) writes:
>>Is it at all possible to reprogram the GPCs from the ground, or does it
>>have to be done from onboard?
>
>They are routinely reloaded with different software from onboard storage
>(tape, I think), but I don't think there is any remote-upload capability.
>In an emergency, the astronauts can input patches manually -- NASA insisted
>on this capability, over IBM's objections (the IBM folks say they considered
>having the patch routine pop up a little flag saying "your warranty is void"
>when it was used :-)) -- but that's not suitable for routine use.
>-- 
>MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
>              -Hal W. Hardenbergh (1985)|  henry@zoo.toronto.edu  utzoo!henry
>
>------------------------------

	Do the GPC's have hard drives?  If so, how do they guard against
shock, vibration, etc?

_______________________________________________________________________________
|                   .sig?  I don't need no stinking .sig!                     |
|                           rborden@ra.uvic.ca                                |
-------------------------------------------------------------------------------
From: moroney@ramblr.enet.dec.com
Subject: Re: FREE-ENERGY TECHNOLOGY For Spacecraft
Organization: Digital Equipment Corporation
Date: Wed, 18 Nov 1992 22:35:38 GMT

In article <1992Nov18.145248.1221@murdoch.acc.Virginia.EDU>, rbw3q@rayleigh.mech.Virginia.EDU (Brad Whitehurst) writes...
>In article <1992Nov17.164440.2394@cnsvax.uwec.edu> mcelwre@cnsvax.uwec.edu writes:

>>                            FREE-ENERGY TECHNOLOGY
>>                       by Robert E. McElwaine, Physicist
>....
>	I think we just found the REAL "Mr. Ozone"!  Is there anyone
>at U. of W. Eau Claire who can verify if this is a real person?  Does
>he do anything but post these articles?

Apparently he also uses every public forum at U. of W. to promote his views
as well.  I have a copy of a message from the director of computing
services at U of W Eau Claire that appears to be sort of a canned response
to complaints.  It suggests sending mail to McElwaine telling him to
cease and desist further postings to inappropiate groups, mailinglists
etc. and he be forwarded copies of correspondence.  (I'll verify the address
and ask permission to give it out/post it, as the message I have is a little
old)

-Mike
Newsgroups: sci.space
From: thep_t@garbo.sunet.se (MAGNUS OLSSON)
Subject: Breasts in zero-g
X-Added: Forwarded by Space Digest
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Distribution: sci
Date: Wed, 18 Nov 1992 10:38:20 GMT


I know this may sound like a weird kind of question, but we were discussing
a comment in an SciFi book about the effect of zero-gravity on a female 
characters breasts, and started wondering what really happens to womens 
breasts in space.  Do women astronauts need to wear bras, for example?

/M


Newsgroups: sci.space
From: fcrary@ucsu.Colorado.EDU (Frank Crary)
Subject: Re: Pumpless Liquid Rocket?
Organization: University of Colorado, Boulder
Date: Mon, 23 Nov 1992 20:15:38 GMT

In article <1992Nov23.160859.9657@cs.ucf.edu> clarke@acme.ucf.edu (Thomas Clarke) writes:
>I was thinking about the problem
>of pumping in a liquid fuel rocket
>and wondered if there might be an
>alternative to fragile turbo pumps
>or heavy pressurized tanks.

>[Description of a gravity-fed rocket deleted.]

>That is connect the tankage to the rocket engine
>with a long pipe.  When accelerating (or at 
>rest in a gravity field) hydrostatic pressure
>at bottom of pipe can be fairly high...

This system has two disagvantages: As acceleration changes, the pressure
(and therefore the fuel flow rate and a few other characteristics of 
the combustion) will also change; also the system will not function in
zero-gravity.

An alternative is a pressure-fed system: A compressed, inert gas (He and
N are popular) is used to keep the fuel tank at some constant pressure,
and thereby force a flow into the lower pressure combustion chamber.

                                                Frank Crary
                                                CU Boulder

Newsgroups: sci.space
From: borden@sol.UVic.CA (Ross Borden)
Subject: shuttle computers
Organization: University of Victoria, Victoria, B.C. CANADA
Distribution: sci
Date: Sat, 21 Nov 92 19:29:02 GMT

>-Do the GPC's have hard drives?  

>I'm virtually certain they don't. Hard disks *are* used in personal
>computers on the Shuttle (after all, they're mighty convenient),
>but they don't have anywhere near 5000 hours MTBF under the conditions
>in the Shuttle. (As I said before, one hard drive on a personal computer
>seized up on the last flight.)

>-If so, how do they guard against
>-shock, vibration, etc?

>-|                           rborden@ra.uvic.ca                                |

>I would guess that they're powered down during launch and landing. (There
>could well be military disk drives that would have a better chance to work
>under those conditions, but even those would be likely to reduce the
>reliability of the GPCs if used in them.)

>John Roberts
>roberts@cmr.ncsl.nist.gov

	Do you have any references on the shuttle computers?  I'd be
interested to find out what kind of fault tolerance they have.

-------------------------------------------------------------------------------
	  "I'd rather have an apendectomy with a burning spatula."
		 	   rborden@ra.uvic.ca
-------------------------------------------------------------------------------

Newsgroups: sci.space
From: fcrary@ucsu.Colorado.EDU (Frank Crary)
Subject: Re: Space suit research?
Organization: University of Colorado, Boulder
Date: Tue, 17 Nov 1992 22:59:02 GMT

In article <BxuEEB.1ow@access.digex.com> prb@access.digex.com (Pat) writes:
>...What i was wondering is why have the shuttle run at 14PSI  
>earth normal atmosphere?   if the shuttle ran on a mostly O2 atmosphere at
>3-4 PSI  wouldnt all the pre breathe stuff become irrelevant?

You don't have to go nearly that far: At 6psi of nitrogen partial
pressure (~9psi total cabin pressure) there wouldn't be any
need for pre-breathing with the current suits.

                                               Frank Crary
                                               CU Boulder
Xref: sparky sci.space:16106 alt.sci.planetary:335
From: plutchak@pilsner.geo.brown.edu (Joel Plutchak)
Newsgroups: sci.space,alt.sci.planetary
Subject: Re: Lunar "colony" reality check
Date: 19 Nov 1992 17:32:57 GMT
Organization: Brown University Planetary Geology
NNTP-Posting-Host: pilsner.geo.brown.edu

In article <1992Nov19.020207.11499@gucis.cit.gu.edu.au> wharvey@gucis.cit.gu.edu.au (Wayne Harvey) writes:
>That would lead to the assumption that the moon would
>be of a different composition than Earth, with possibly greater concentrations
>of elements (mineable (sp?) quantities). This would change the picture 
>somewhat, when you assume that the only mineral explorations done on
>the lunar surface were conducted in the equivalent of the Sahara.

   Could you clarify that last statement?  Start with defining
"mineral explorations" and what "conducted in the equivalent of
the Sahara" means.
   I know that imaging data from which one can infer mineral
composition is not very abundant for the Moon, but the Galileo
encounter(s) and Earth-based telescopic studies have contributed
somewhat to our understanding of the composition of the lunar
surface.  See various recent publications for further information,
e.g. proceedings of the Lunar & Planetary Science Conferences, the
American Geophysical Union conferences, and Science magazine.
(And look for more results from next month's second Galileo
encounter of the Earth/Moon system.)
--
Joel Plutchak, Research Programmer/Analyst
Newsgroups: sci.space
From: steve@fulcrum.oz.au (Steve Taylor)
Subject: Re: FREE-ENERGY TECHNOLOGY For Spacecraft
Organization: The Fulcrum Consulting Group
Date: Mon, 23 Nov 1992 23:08:09 GMT

mcelwre@cnsvax.uwec.edu writes:

>     The technology described in the article copied below could be used to
>power spacecraft, space colonies, etc.:
>          
>            
>                            FREE-ENERGY TECHNOLOGY
>                       by Robert E. McElwaine, Physicist

Didn't you post this gibberish a month or so ago? How about some new stuff?
Organization: Carnegie Mellon, Pittsburgh, PA
Newsgroups: sci.space
Date: Tue, 17 Nov 1992 14:28:20 -0500 
From: Kevin William Ryan <kr0u+@andrew.cmu.edu>
Subject: Re: Space suit research?
Distribution: sci

roberts@cmr.ncsl.nist.gov (John Roberts)
>-What's the big push for a earth normal type atmosphere?
>-apollo, etc, ran fine on low pressure pure O2,  does better pressure 
>-greatly improve cooling.  
> 
>(1) Henry says it does.
>(2) It "stands to reason" - five times as many molecules to conduct the
>heat.
> 
>-or are there long term bio effects????
> 
>There *may* be. For example, one of the Apollo astronauts, after a busy day
>on the moon, had bleeding under his fingernails - thought to be mainly a
>result of the low pressure. Little indications like that made NASA uneasy. :-)

    I would have thought that was from the Apollo suit gloves: they are
quite stiff under pressure and several astronauts reported sore fingers
from forcing them closed. 

                                                    kwr

Internet: kevin.ryan@cmu.edu

Newsgroups: sci.space
From: andy@osea.demon.co.uk (Andrew Haveland-Robinson)
Subject: Re: Putting telescopes on the moon 
Distribution: world
Organization: Haveland-Robinson Associates
X-Mailer: Simple NEWS 1.90 (ka9q DIS 1.18)
Date: Tue, 17 Nov 1992 03:26:58 +0000


In article <Bxs37M.M81.1@cs.cmu.edu> roberts@cmr.ncsl.nist.gov writes:

>-But, you ask, so what?  Won't mixing the signals from the combined
>-telescopes in the array isolate the light from the planet?  Well, yes 
>-and no.  You can boost the signal-to-noise ratio by an amount that's
>-proportional to the number of telescopes in the array.  That might
>-allow you to detect the presence of the planet, where you couldn't
>-otherwise.  But unless you start with a pretty clean signal in the 
>-first place, there will be far too much noise to allow anything like 
>-imaging of continents.
>
>Would speckle interferometry, or integration of the incoming signals over
>very long periods of time (hours to weeks) help with reception? (Other than
>the fact that planets move over such time intervals.)
>
>I think you've made your point that the resolution formula can't be extended
>out to infinity. I'd be interested in how far it *can* be extended with, say,
>100 high-precision 10-meter optical telescopes.
>
>John Roberts
>roberts@cmr.ncsl.nist.gov

Be good for SETI too - I expect the moon would act as an effective shield
against the electromagnetic crap emanating from our orbiting toilet... :-)

Just a matter of time I guess (<1,000 years?)

Andy.

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>>>> Those that can, use applications. Those that can't, write them! <<<<
> Some dream of doing great things, while others stay awake and do them <
From: flb@flb.optiplan.fi ("F.Baube x554")
Subject: Aurora
X-Added: Forwarded by Space Digest
Organization: [via International Space University]
Original-Sender: isu@VACATION.VENARI.CS.CMU.EDU
Distribution: sci
Date: Wed, 18 Nov 1992 11:23:36 GMT

	Can anyone summarize the rumors and speculation
about the "Aurora" black project ?  Perhaps some comments 
about the technologies that are involved, and what that 
would mean for the development of SSTO, DC-X, HL-20. etc. ?

	fred :: baube@optiplan.fi
From: ujacampbe@memstvx1.memst.edu (James Campbell)
Newsgroups: sci.space
Subject: Re: What kind of computers are in the shuttle?
Date: 18 Nov 92 22:17:16 -0600
Organization: MSU Cryptosystems

In article <1992Nov17.015422.6155@engage.pko.dec.com>, 
                                           moroney@ramblr.enet.dec.com writes:
> In article <18741@ksr.com>, jfw@ksr.com (John F. Woods) writes...
>>Rad-hard SRAM, 50 bits of ECC for each 32 bits of memory, *and* a background
>>scrub cycle every two seconds.  They didn't buy this at "BACK OF THE TRUCK
>>PEECEES, LIMITED", nosir!
> 
> Interesting.  Would you happen to know how many errors this memory can detect
> and correct?
> 
> -Mike

Only two:  0's that should have been 1's, and 1's that should have been 0's. ;)

Sorry, I couldn't resist.
Newsgroups: sci.space
From: amon@elegabalus.cs.qub.ac.uk
Subject: Re: Shuttle computers
X-Added: Forwarded by Space Digest
Organization: [via International Space University]
Original-Sender: isu@VACATION.VENARI.CS.CMU.EDU
Distribution: sci
Date: Mon, 23 Nov 1992 17:17:42 GMT

> I wonder if they've ever considered a system by which a spare tape can be 

> written by instructions from the ground, for checking and subsequent loading
> into the GPCs. That could be useful if (for instance) one of the flight
> control surfaces is damaged in an unanticipated way, and the basic flight
> protocol has to be modified. Writing to a tape would overcome some of the
> objections to direct loading of programs from the ground.
> 


I see your point, but I suspect the time required to modify and certify the  
flight software would be far too long. If the surfaces are damaged in some way,
could it actually be modeled quickly enough? Could a program written in low  
level code be flight qualified and uploaded in time? I doubt it.

Probably better off going with the existing control program and using the
best flight control computer ever designed. Comes standard (1, each) with a  
Right Stuff Pilot. Preinstalled between ears.

Now if you want to talk about noncritical flight regimes, that might be more  
practical. Even so, the program development is (or at least was) one of the  
major bottlenecks on shuttle flight rate.

Actually, calling these thing GPC is almost a misnomer. They run simple (by the  
standards of complexity we are using to communicate with) sequential programs.  
Only one program runs at a time. During critical flight phases the programs are  
pre-loaded. On launch I think they also have an abort Major Mode loaded as well.
Each program also has minor modes, which are mostly display option I believe.

I'm not sure they even run an operating system. I don't think they even use  
interrupts because that makes programs too unpredictable. All this is discussed  
in great detail in the ACM paper whose citation I posted recently.




Newsgroups: sci.space
From: ERICLANE%UTCVM.bitnet@CUNYVM.CUNY.EDU ("Prof. Eric T. Lane")
Subject: message from Space Digest
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Distribution: sci
Date: Mon, 23 Nov 1992 19:21:32 GMT

help

I'm writing an article on Physics resources on bitnet and internet.

Thanks, Eric Lane.
Newsgroups: sci.space
From: amon@elegabalus.cs.qub.ac.uk
Subject: Re: Shuttle replacement
X-Added: Forwarded by Space Digest
Organization: [via International Space University]
Original-Sender: isu@VACATION.VENARI.CS.CMU.EDU
Distribution: sci
Date: Sat, 21 Nov 1992 20:16:06 GMT

> That means all it needs for the second launch is to be re-fueled.
> 


Well, I'll pick a rather important nit: No pilot in their right mind  
gets behind the wheel/stick without doing a careful walkaround  
pre-flight. I expect that an operational DC1 vehicle will put the  
pilot back into the loop in a way they never were or could be on the  
Shuttle. With aviation style operations and complexity comes aviation  
style checklists and hands on pilot responsibility. And a hearty amen  
to that, brother.

				a former almost-pilot
				priced out of the air
				by lawyers and bureaucrats,

					Dale Amon

Newsgroups: sci.space