HDTenEightyP/NetNews huggingface dataset:
From: quest@iowegia.uucp (Steve J. Quest)
Newsgroups: sci.space
Subject: Re: Home made rockets
Date: 16 Aug 92 06:11:54 GMT
Organization: Iowegia Waffle BBS, Clive IA USA, +1 515 226 2156

roberts@CMR.NCSL.NIST.GOV (John Roberts) writes:

> Just so long as nobody tries to "improve" the design by adding more match
> heads or strengthening the containment. Match phosphor has a reputation as
> a powerful and unstable propellant/explosive.


John,

        I just thought I should point out that it is not phosphor, 
or more exactly phosphorus that is found in a match head (save for 
the strike anywhere type).  Match heads are a mixture of potassium 
chlorate and antimony sulphide.  It is bound with gum arabic or 
tragecanth.  When you strike a match against the red stripe on a 
match book, you are providing friction and an oxidizer to the 
stripe, which is made of red phosphorus.  The phosphorus burns, 
produces great localized heat, and lights the match head.  Strike 
anywhere matches have a mixture of red phosphorus and "match head 
composition" at the very tip.  Just a clarification comment...sq
Newsgroups: sci.space
From: mt87692@cs.tut.fi (Mikko Tsokkinen)
Subject: Re: Parsecs?
Organization: Tampere University of Technology
	<1992Aug12.013040.618@leland.Stanford.EDU>
	<1992Aug12.024141.4913@utdallas.edu>
	<ZOWIE.92Aug12004854@daedalus.stanford.edu>
Date: Thu, 13 Aug 1992 14:36:08 GMT

In article <ZOWIE.92Aug12004854@daedalus.stanford.edu> zowie@daedalus.stanford.edu (Craig "Powderkeg" DeForest) writes:

> This talk of parsecs and so forth reminds me of my favorite volumetric unit:
> the barn megaparsec.

> A barn is a unit of atomic cross-section, 10^-20 cm^2.  A barn megaparsec is
> about 1.6 teaspoons!

> --
> Craig DeForest:  zowie@banneker.stanford.edu  *or*  craig@reed.bitnet

And from jargon file:

attoparsec: n. `atto-' is the standard SI prefix for
   multiplication by 10^{-18}.  A parsec (parallax-second) is
   3.26 light-years; an attoparsec is thus 3.26 * 10^{-18} light
   years, or about 3.1 cm (thus, 1 attoparsec/{microfortnight}
   equals about 1 inch/sec).  This unit is reported to be in use
   (though probably not very seriously) among hackers in the U.K.  See
   {micro-}.

 Mit
xxxxx
--
Save bandwidth and nerves! Use small signature!
-- 
Xref: sparky sci.space:12066 sci.astro:9104
From: ephillip@magnus.acs.ohio-state.edu (Earl W Phillips)
Newsgroups: sci.space,sci.astro
Subject: wefax
Date: 21 Aug 92 01:48:38 GMT
Article-I.D.: magnus.CMM.0.90.2.714361718.ephillip
Organization: The Ohio State University

Does anyone know who, where, to contact to sign up
for wefax?

*****************************************************************
*                                    | ====@====      ///////// *
* ephillip@magnus.ircc.ohio-state.edu|     ``________//         *
*                                    |       `------'           *
*                 -JR-               | Space;........the final  *
*                                    | frontier...............  *
*****************************************************************
Newsgroups: sci.space
From: russ@pmafire.inel.gov (Russ Brown)
Date: Mon, 17 Aug 92 13:42:45 GMT
Organization: WINCO
Subject: Re: He3 Power Source
Summary: 
Followup-To: 
Organization: WINCO
Keywords: 

In article <133269@lll-winken.LLNL.GOV> roberts@phoenix.ocf.llnl.gov (Don Roberts) writes:
>eatlv@cbnewsg.cb.att.com (thomas.vandoren) writes:
>
>>About 2 weeks ago I saw a series of 5 minute modern videos of great interest.
>>One of them was about a proposal to use Helium3 mined from the moon as a power
>>source on Earth. [...]
>>
>>Does anyone have more info, opinions on that proposal? [...]
>>
>>How hypothetical is this and is it practical?
>>
>>Lee
>
>At present it's *very* hypothetical, and *highly* impractical. The way to
>use He3 for power generation is via nuclear fusion [1]:
>
>D + He3 -> He4(3.6MeV) + p(14.7MeV)
>
>However, the reaction rate parameter (related to the fusion reaction cross
>section and the relative speed of the reactants) is by far the highest for
>the deuterium-tritium reaction:
>
>D + T -> He4(3.5MeV) + n(14.1MeV)
>
>Using D-T fusion, the major magnetic fusion experiments, in England and
>the U.S., could presently only produce between 0.3 and 0.7 of the input
>power needed to sustain the experiment [In fact these machines study D-D
>fusion, which generates far less fusion power but only produces about half
>as many neutrons, at lower energy.  D-T experiments are planned at each
>facility within the next few years].
>
>D-He3 fusion, while more environmentally benign (*much* lower neutron
>production, leading to less activation, structural fatigue, etc.) requires
>temperatures about ten times as great to attain similar reaction rates.
>Even then, it would probably require higher plasma densities, further
>complicating matters. In other words, we haven't licked the "simple"
>problem yet (D-T) fusion, so don't hold your breath waiting for the tough
>one (D-He3).
>
>I think the lunar "environment" is safe from marauding bands of
>strip-miners. For the time being...
>

In addition to the physics/engineering problems, the logistics of
remotely operated, fueled, and maintained mining of about 20 million kg of
lunar rock to fuel a 1 GWe reactor would be considerable.  The
processing of this amount of material to recover the He-3 would also be
a challenge.

If deuterium-helium-3 were now achievable, the difficulties of a lunar
mining venture might still be more than enough to make it impractical.
From: amon@elegabalus.cs.qub.ac.uk
Newsgroups: sci.space
Subject: Re: Beanstalks in Nevada Sky (was Re: Tethers)
Date: 17 Aug 92 15:49:29 GMT
Article-I.D.: cs.Bt4xEG.Lqq.1
Distribution: sci
Organization: [via International Space University]
X-Added: Forwarded by Space Digest
Original-Sender: isu@VACATION.VENARI.CS.CMU.EDU

I would suggest you look into Lofstrom Loops and other active,  
surface based structures. Theoretically you can build a tower 100km  
high with this technology.

Should be something on it in the FAQ's. It's been discussed over and  
over again all the way back to Space Digest V1 in 80-81.
Newsgroups: sci.space
From: jbh55289@uxa.cso.uiuc.edu (Josh 'K' Hopkins)
Subject: Return of payloads from Freedom
Organization: University of Illinois at Urbana
Distribution: sci
Date: Thu, 20 Aug 1992 14:58:25 GMT

amon@elegabalus.cs.qub.ac.uk writes:

>> Allan you have still not addressed with numbers the propostion that  
>the
>> Shuttle will become MORE useful as the return of large payloads  
>grows more
>> common in the SSF era.
>>

>WHAT large payloads? There ARE no large payloads until we actually GO  
>somewhere. There is nothing in LEO to bring back. And if we do have  

	On the contrary, as currently designed, Freedom requires the return
of materials on a regular basis.  The engines are designed in 6 (?) modules
that require refueling on Earth.  Current plans have them being rotated out
on a regular baisis.  Since these are almost certainly too large to return in
a Soyuz, you're going to need to redesign them (previously they would have been
H2-LOX run off waste water but that was expensive), or add a vehicle that
can return moderate size payloads.  Or maybe this was covered and I just missed
it.

>The shuttle has already lived a longer time than most of the really  
>early cargo aircraft (ie pre-Ford Trimotor and DC-3). It will have an  
>honored place at NASM and will probably be sitting there before 2005.

	Well, just to pick nits, NASM already has a shuttle and DC-3s are still
flying.  One has the equivalent of something like 6 million miles on it.  Pre-
DC-3 craft probably weren't popular for long, but I bet there were some that 
flew for 15 years.


-- 
	Josh Hopkins       j-hopkins@uiuc.edu, or jbh55289@uxa.cso.uiuc.edu

		"A goal is a dream taken seriously."	-Uncle Walt.
From: moravec@Think.COM (Hans Moravec)
Newsgroups: sci.space
Subject: Re: beanstalk in Nevada
Date: 12 Aug 1992 20:53:50 GMT
Organization: Thinking Machines Corporation, Cambridge MA, USA
Distribution: sci.space
NNTP-Posting-Host: turing.think.com

In article <STILES.92Aug12133223@quik.clearpoint.com>, stiles@quik.clearpoint.com writes:
|> Wouldn't it be possible to have a beanstalk terminus in Nevada just as long as
|> you had a complimentary terminus an equal distance south of the equator, to
|> form a dual stalk beanstalk?  As I envision this thing, there would be a single
|> upper terminus, located directly above the equator, and the lines descending
|> from it would have a catenary shape.  Of course, it would be difficult enough
|> doing a beanstalk to a terminus on the equator, but as long as we are dreaming
|>  ...

It shouldn't be necessary to balance a non-equatorial synchronous beanstalk
with one on the other side of the equator.  Imagine that you start by
building an equatorial version, anchored by a big weight (and pulled
taut by a counterweight way out beyond synchronous orbit).  Then load the
anchoring weight on some kind of transport and move it (slowly!) to Nevada.
The beanstalk won't fall, it will just begin to LEAN equatorward, following
gradient lines that can be imagined as vector sums of gravity pulling
to earth center, and centrifugal force pulling perpendicular to earth's
rotation axis (rather than center).  Something like a catenary.

				-- Hans Moravec

He who refuses to do arithmetic should carry a calculator
From: amon@elegabalus.cs.qub.ac.uk
Newsgroups: sci.space
Subject: Re: Meteor Soaks Datona FL
Date: 18 Aug 92 15:28:42 GMT
Article-I.D.: cs.Bt6s7C.1Dq.1
Distribution: sci
Organization: [via International Space University]
X-Added: Forwarded by Space Digest
Original-Sender: isu@VACATION.VENARI.CS.CMU.EDU


> plunging to Earth. Meteors have impact velocities as high as 40
> miles per second. If the 1 meter meteor was iron, it's impact would
> release kinetic energy equivalent to a 65 kiloton nuclear  
explosion.
> It's not like tossing a pebble into a pond.
> 


Not true. Small bodies are travelling at not much over terminal  
velocity when they strike. Have you ever touched the boulder sized  
meteorite in the Smithsonian? It's probably more in the 2-3 meter  
class, is just rock ... and is intact. It could HARDLY be sitting in  
the Smithsonian after releasing several Hiroshimas of energy.

Or seen photos of the tall as a person one sitting in Africa (never  
moved from the site where it was found). I think there is a photo of  
this one in the recent Time/Life Space series volume on meteorites &  
such.

A very fat woman was actually hit by a meteorite once. It came  
through the roof and hit her. I saw the photo in a book on the  
subject. Quite a large black and blue mark on quite a large woman.

They are also, interestingly enough, not hot when they land. The  
heating is also superficial and the interiors are still at outer  
space temperatures. Frost can form on them after striking as the cold  
"leaks out".

I actually tend to doubt the reports of it causing a wave because I  
don't think a 1M rock would raise much of a wave at all. Probably not  
a lot more than dumping it out of an airplace a couple miles up.

Of course as the meteorites get large, the impact velocity increases  
because the ratio of mass to cross sectional surface area increases  
rapidly as the object gets larger: ie more energy needs dissapated in  
the same amount of time and over a smaller area.

There have been postings about 1M rocks making 10M craters. I would  
suggest you would get the same crater size by just dumping a chunk of  
granite out the back of a Hercules cargo plane from FL350.
Newsgroups: sci.space
From: dcutter@oregon.uoregon.edu (dann cutter)
Subject: Private space ventures
Organization: Stellar Enterprises
Date: Fri, 14 Aug 92 06:38:42 GMT

Could anybody out there please tell me the current status of the private
space industry world wide. What comapnies exist... what they have done...
thanks

_______________________________________________________________
Dann Cutter  Stellar Enterprises /
dcutter@oregon.uoregon.edu
From: aws@iti.org (Allen W. Sherzer)
Subject: Re: Energya and Freedom and Soyuz ACRV and...
Organization: Evil Geniuses for a Better Tomorrow
Date: Tue, 18 Aug 1992 10:57:00 GMT

In article <1992Aug17.154937.24078@ke4zv.uucp> gary@ke4zv.UUCP (Gary Coffman) writes:

>Indeed. If we follow the plan of using Soyuz and HL Deltas, the Shuttle
>fleet is *gone*. 

OK, I have posted extensive numbers on the alternatives. Let's see some
numbers from you. What will the Shuttle do that will not only justify the huge
expense of keeping it but also pay for the opportunity cost of the cheaper
infrastructure?

I await your reply.

>With this plan 3/4 of the 
>Shuttle fleet is available for other work than servicing Fred.

Shuttle flies about eight times a year (at least it has for the last
2 years and looks like it will do so this year). Since using Shuttle
as the ACRV will about half the number of flights there will be NO
non station shuttle flights.

Thus we will be spending $5 billion each and every year to resuply the
station. That's an interesting number since you could build the
Porche of ACRV's for that and could do ALL your tasks for 20% of that
figure.

>As to the $65 million firm price for Soyuz, I've posted about this
>several times. 

1. That is about three times the price I have seen for a Soyuz. I am
assuming $100M per Atlas/Soyuz launch even though the actual cost will
likely be much closer to $75 million.

2. We are stuck with Soyuz anyway since we won't get an ACRV.

3. Lots can be done to mitigate this. We can sign long term contracts,
build in the US under licence, or a number of other alternatives.

   Allen
-- 
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "If they can put a man on the Moon, why can't they     |
|  aws@iti.org     |  put a man on the Moon?"                               |
+----------------------248 DAYS TO FIRST FLIGHT OF DCX----------------------+
From: sth@slipknot.mit.edu (Scott Hannahs)
Newsgroups: sci.space
Subject: Re: He3 Power Source
Date: 14 Aug 92 23:50:11 GMT
Organization: Massachvsetts Institvte of Technology

roberts@phoenix.ocf.llnl.gov (Don Roberts) writes:
>eatlv@cbnewsg.cb.att.com (thomas.vandoren) writes:

>>About 2 weeks ago I saw a series of 5 minute modern videos of great interest.
>>One of them was about a proposal to use Helium3 mined from the moon as a power
>>source on Earth. [...]
>>
>>Does anyone have more info, opinions on that proposal? [...]
>>
>>How hypothetical is this and is it practical?
>>
>>Lee

>At present it's *very* hypothetical, and *highly* impractical. The way to
>use He3 for power generation is via nuclear fusion [1]:

Useful discussion on fusion deleted (it does lower the production of
nasty neutrons)

>I think the lunar "environment" is safe from marauding bands of
>strip-miners. For the time being...

>Reference:

> Dr. Donald W. Roberts

Any reason the moon should be richer in 3He than the earth? The natural
abundance of 3He is about 7ppm in regular 4He which is from trapped
alpha decay in natural gas wells.  I think the energy cost of gettting
to the moon, mining the 3He and bringing it back would be more than you
can get out of the 3He.  The major (only) commercial source of 3He (~$90
US / liter STP federal research grant rates) is from nuclear weapons
manufacture.  If you have some tritium around all you have to do is sit
on your thumbs and bingo 3He.  Now that the arms race is over all the
low temp physicists should start worrying about the availability of 3He.
For awhile as warheads are deactivated things will be ok, but
eventually....  No more research below 1K.  We do recycle the stuff but
nothing is 100% effecient.

Scott Hannahs, F. Bitter National Magnet Lab, sth@slipknot.mit.edu
Newsgroups: sci.space
From: henry@zoo.toronto.edu (Henry Spencer)
Subject: Re: SPS fouling astronomy
Date: Wed, 12 Aug 1992 20:28:06 GMT
Organization: U of Toronto Zoology

In article <1992Aug12.044959.19501@dartvax.dartmouth.edu> Frederick.A.Ringwald@dartmouth.edu (Frederick A. Ringwald) writes:
>...issue of COST is unresolved, however, but come to think of it, is there
>any reason SPS *must* be a mega-engineering project? Might there be
>some way of doing it simply?

Unfortunately, if you use microwaves there is a fundamental problem:  to
keep the size of the receiving rectenna manageable, you *must* have a
transmitting antenna on the order of a kilometer wide, assuming your
bird is in Clarke orbit.  (An order-of-magnitude approximation is that
the product of the antenna radii must exceed distance times wavelength.)

Laser transmission would scale down better, but runs into the weather
problem, which microwaves largely avoid.
-- 
There is nothing wrong with making      | Henry Spencer @ U of Toronto Zoology
mistakes, but... make *new* ones. -D.Sim|  henry@zoo.toronto.edu  utzoo!henry
From: Mark Goodman <mwgoodman@igc.apc.org>
Newsgroups: sci.space
Date: 18 Aug 92 07:22 PDT
Subject: space industry
Nf-ID: #N:cdp:1469100011:000:1920
Nf-From: cdp.UUCP!mwgoodman    Aug 18 07:22:00 1992


To:    
From:  Mark Goodman (mwgoodman@igc.org)
Re:    
Date:  
 
dcutter@oregon.uoregon.edu (dann cutter) writes:
 
>Could anybody out there please tell me the current status of the private
>space industry world wide. What comapnies exist... what they have done...
>thanks
 
I can only give you a sketch of the answer, which is all I know.
The first thing that comes to mind is the private space launch
industry, which doesn't really exist.  What exist are a number
of government/corporate ventures (France/Arianespace, China/
Long March, etc.), and a number of aspiring companies in the
United States.  There are really no private space launch providers
outside the United States -- Arianespace is the closest thing.
 
But the space industry is much more than that.  It includes
satellite makers (a handful in the U.S., Spar in Canada, Matra/
Marconi and maybe others in Europe, Japan?, others?), companies
that provide satellite imagery (Eosat, Spotimage, Soyuzkarta),
companies that make communication satellite downlink antennas,
companies that make components for all these systems, and more.
 
In general, ground services are more profitable than satellites
are more profitable than launchers, and nothing else is profitable.
The space launch industry suffers from serious problems of oversupply.
I think it is also true that the more profitable sectors are more
widely spread around the world, especially at the component level.
I believe India sells some satellite components, for example.
 
I hope this helps.  I'm sure others will jump in if I've said
anything wrong (or right but controversial).
 
+-----------------------------+-----------------------------+
|       Mark W. Goodman       | What a terrible thing it is |
| mwgoodman@igc.org -- econet | to lose your mind.          |
| goodman@ksgbbs.harvard.edu  |                             |
+-----------------------------+-----------------------------+
From: amon@elegabalus.cs.qub.ac.uk
Newsgroups: sci.space
Subject: Re: Capsule location list
Date: 12 Aug 92 12:16:11 GMT
Article-I.D.: cs.1992Aug12.121759.190221
Distribution: sci
Organization: [via International Space University]
X-Added: Forwarded by Space Digest
Original-Sender: isu@VACATION.VENARI.CS.CMU.EDU

There is also Grissom's Mercury capsule, Liberty Bell 7 (if I  
remember my Mercury's) which is still sitting at the bottom of the  
Atlantic, a hundred or so miles out from the Cape.

There was at least one proposal to recover it. A few years back Todd  
Hawley had an article on how to retrieve it and where it was.
From: Frederick.A.Ringwald@dartmouth.edu (Frederick A. Ringwald)
Newsgroups: sci.space
Subject: Re: He3 Power Source
Date: 13 Aug 92 22:03:50 GMT
Organization: Dartmouth College, Hanover, NH

In article <1992Aug13.190624.1512@cbfsb.cb.att.com>
eatlv@cbnewsg.cb.att.com (thomas.vandoren) writes:

> My only concern or potential skepticism is how easy is it to develop an
> He3 power plant?  I mean are we talking something as hypothetical as fusion
> power

It *is* fusion power, and of an advanced kind, at that.
Newsgroups: sci.space
Newsgroups: sci.space
Subject: Re: Germans drop European Shuttle ?
From: schar@ssdvax.mdcbbs.com
Date: 14 Aug 92 07:16:35 GMT
Organization: McDonnell Douglas - Space Station Division, Huntington Beach CA
Nntp-Posting-User: schar

In article <pgf.713577979@srl02.cacs.usl.edu>, pgf@srl02.cacs.usl.edu (Phil G. Fraering) writes:
> <RFLOOD@ESOC.BITNET> writes:
> 
>>Whilst skimming thru the TV channels last week, I caught sight of the
>>German research minister, Riesenhuber, saying that Hermes was 'unacceptable'
>>(not exact translation) to the German government in either manned or unmanned
>>form. 
> 
> Hey! He's probably just tired of the way the French have shut down all
> launch vehicle research besides Hermes/Ariane V in ESA...
> 
> To wit, Saenger and Hotol...

Could be.  It could also be that the Ariane 5 payload to orbit capacity has
been shrinking steadily, while Hermes weight has been increasing steadily. 
Since Hermes is intended to be launched on Ariane 5, the combination of these
two factors is not good.  The last I heard, Hermes had a payload capacity of
800 pounds (excluding the three astronauts).  Since there are a plethora of
small rockets that can launch an 800 pound payload fairly cheap, it doesn't
make a lot of sense to spend billions of dollars/marks/francs on a new method
of dropping 800 pounds of payload in orbit.

-- 
Brian Schar   |  schar@ssdvax.mdcbbs.com
McDonnell Douglas Space Systems Company, Huntington Beach, CA
Disclaimer:  Any opinions here are mine, not my employer's.  Any facts are in
the public domain.
____________________________
Andre Marrou & Nancy Lord: Vote Libertarian for President & VP in 1992! 

Getting the Power Back to You: Richard Boddie & June Genis--U.S. Senate--CA
From: eder@hsvaic.boeing.com (Dani Eder)
Newsgroups: sci.space
Subject: Re: Tethers
Date: 17 Aug 92 15:55:43 GMT
Distribution: na
Organization: Boeing AI Center, Huntsville, AL

evansmp@uhura.aston.ac.uk (Mark Evans) writes:

>Eric_S_Klien@cup.portal.com writes:
>: Would it be possible to put something in near orbit over Nevada and 
>: attach tethers to it so that people could reach the object via 
>: elevators?  I know it wouldn't be easy, but is there a way to pull 
>: this off?

>read 'The fountains of paradise' bye Clake.

>The only way you can get something to orbit above  point of the earth's
>surface is to have it in geo-sync orbit.
>Thus, the point you have your satellite above must be on the equator.
>(if you want it to be over pointelse where on the globe, then it is
>not in orbit and must run thrusters virtually continuiously to stay in
>position)

I do not believe this is correct.  It is true that the center of
gravity of the 'beanstalk' needs to be in Clarke Orbit so it does
not wobble.  The attachment point on the ground, however, can be
off the equator.  You elevator in this case will form a catenary,
i.e. it will be curved.  This will require more structure than the
simpler vertical case, so it is not usually considered, but it is
not ruled out on physical grounds.

 Dani

-- 
Dani Eder/Boeing/Advanced Civil Space/(205)464-2697(w)/232-7467(h)/
Rt.1, Box 188-2, Athens AL 35611/Member: Space Studies Institute
Physical Location: 34deg 37' N 86deg 43' W +100m alt.
***THE ABOVE IS NOT THE OPINION OF THE BOEING COMPANY OR ITS MANAGEMENT.***
Newsgroups: sci.space,sci.astro