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Date: Wed, 18 Apr 90 01:48:34 -0400 (EDT)
Subject: SPACE Digest V11 #277

SPACE Digest                                     Volume 11 : Issue 277

Today's Topics:
            A revised survey (apologies!).
          Re: Pegasus launch from Valkyrie  (or ...
                 Re: Needles
                unsub
              Re:  SPACE Digest V11 #256
              Re:  SPACE Digest V11 #256
           Re: Whip launch as first stage?
           Re: The effects of decompression
       Re: Drake Equation (was Re: Interstellar travel)
----------------------------------------------------------------------

Date: 17 Apr 90 15:16:12 GMT
From: jarthur![e-mail]  (Todd Courtois)
Subject: A revised survey (apologies!).


Unfortunately, my partner and I have decided that our the first
version of the survey was severely flawed.  We offered too few choices
on many of the questions, and some questions might have lead people to
answer a certain way.

Thus, attached is a revised survey.  The questions are the same, and
all of the old answer choices are available, but there are  more choices
available on each question.

Just follow the same instructions as before, and because there has been
so much written response to our survey, please send any COMMENTS or
SUGGESTIONS to  [e-mail] or
[e-mail].  But please PLEASE only send survey responses
to tcourtoi@jarthur as mentioned before.

Note that if you send a revised survey form, I will discard the first,
but your second form will still be used.
BTW,  Please feel free to post the revised survey to newsgroups.

Fellow usenetters:

Sorry to disturb this illustrious newsgroup, but I am hoping that you can
help me.  Currently I am working on a research paper which asks the "simple"
question, "Why are there disproportionally few women in math and science?"

So how can you help me?  Well, below are just a few short questions with
standardized answers.  Both males and females are encouraged to reply, but
note that we will only accept one reply per username.  Please send your
replies to one of the following addresses :

[e-mail]
uunet!jarthur!tcourtoi

Please put "SURVEY" in the subject line.

Note that following the questionnare is a sample e-mail answer.  Please
follow this format EXACTLY (it isn't difficult) because we are going to
process these through the computer, and it's going to reject anything that
isn't standard (thus your views won't count).

Questions:

1. Are you female or male? F M

2. Are you a scientist, engineer, mathematician or computer scientist? Y N
   (This includes any technical area requiring at least a bachelor's
     degree, and programmers or technical support staff).

3. Do you feel you've been discriminated against in hiring, promotion,
   recognition, etc. because of your gender?
   Not discriminated against>  1  2  3  4  5 <Discriminated against

4. In your opinion, which sex receives preferential treatment in hiring,
   promotion, recognition, etc. in your profession?
   Female> 1  2  3  4  5 <Male   0>Neither

5. Do you feel you are treated the same as people of the opposite sex
   with similar background and qualifications?
   Worse> 1  2  3  4  5 <Better  0>About the same

6. In your opinion, is less gender bias more apparent in your profession
   than in other, non-technical professions?  Y N

7. Do you feel inferior in technical ability (programming skill, math
   ability, design creativity) to your counterparts of the opposite sex? Y N
    (NOTE this means *inherent ability*, NOT training-- see next question).

8. Do you feel that your educational background or training was less
   strong than your peers' of the opposite sex? Y N

9. Do you feel that, in general, there is a bias against the opposite
   sex  in your profession?  Y N

10. Do you feel women sacrifice their careers for family more often/more
    severely than men?  Y N

Sample Answer reply (just send an e-mail message which has this format):

M Y 3 4 0 Y Y N N N


Note that there are ten questions and ten answers.  Each answer is only
one upper case character followed by a space, and is either a letter or
a number.

Please send comments to [e-mail].  Please send surveys
ONLY to the tcourtoi@jarthur addresses listed above.

Thanks for your cooperation!  In a few weeks when all the replies have been
processed I will post the results to all the newsgroups in which this
questionaire has appeared.

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

Date: 17 Apr 90 22:43:25 GMT
From: usc!samsung!rex!rouge![e-mail]  (Fraering Philip)
Subject: Re: Pegasus launch from Valkyrie  (or ...


About all of this talk about adapting the Pegasus to other airplanes:

It looks like y'all are really building up to a real goat-roping to me.

The carrier airplane isn't the problem in terms of high launch cost.
The Pegasus rocket itself might be.

Keep in mind that it took somewhere around $ 40 million to develop and
build, which is probrably less than some of the carrier aircraft being
proposed here.

A fully or partially reusable vehicle using RL-10 engines, similar to
Third Millenium Inc.'s _original_ design for the Space Van, and with
multiple stages, would probrably have a lower price.

Third Millenium was, as far as I can tell, unsucsessful at obtaining
investment capital. Of course, now that air-launch of spacecraft has
been shown to be possible, getting capital should be easier.

So, in summary: please stop bugging Mary Shafer about which of the
experimental aircraft in her stable at Dryden will improve the
performance of a launcher that uses 325 Isp fuel when (although with
a little more difficulty) 450 Isp fuel (Hydrogen/Oxygen) could be used
instead. Think about it.

Remember: The cost of developing Pegasus from point zero: $40 million.
Cost of refurbishing B-70 Valkyrie: probrably lots more.

Philip Fraering
[e-mail]
"I'm troubled, I'm dissatisfied, and I'm Irish." - Marianne Moore

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

Date: 4 Apr 90 02:32:03 GMT
From: mitel!sce!cognos!geovision![e-mail]  (Gord Deinstadt)
Subject: Re: Needles

In article <[e-mail]> [e-mail] (Brian or James) writes:
>
> Does anyone out there have information on an early (late fities
>to mid-sixties) project to place millions of needled in LEO as a
>passive radio relay.

Project West Ford.  Westford was one of the military bases involved;
naming rules dictated two words.

>I *think* it was DOD related (a stop gap
>technique to use if the US comsats got fried)

Yes.

>and I recall Clarke
>discussing it briefly in on of his books. The needles, if they were
>launched, obviously must have reentered long ago, if only because
>noone ever  has a payload turned into a sieve by hordes of orbitting
>sewing tools. The radio astronomers must have *loved* this project.

Everybody "loved" :-) this project.  Actually the "needles" were
very small pieces of copper wire - whiskers would be a better description.
There was oodles of opposition, both from astronomers (including
visual astronomers) and doomsayers.  The launch took place, the "needles"
were invisible from the ground except at resonant microwave frequencies,
and within a month or two they had all re-entered.

Disclaimer: this is all from memory from an article I read about six
months ago.  Not even sure which magazine the article was in, possibly
"Smithstonian Air & Space".
--
Gord Deinstadt  [e-mail]

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

Date: 17 Apr 90 16:44:00 EST
From: "LAMBERT        ,CAROL     ,BAC" <[e-mail]>
Subject: unsub
To: "space" <[e-mail]>

unsub [e-mail] space digest shawn hayhurst

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

Date: 18 Apr 90 01:01:45 GMT
From: snorkelwacker!mintaka!oliveb!tymix!hobbes![e-mail]  (Phil Nelson)
Subject: Re:  SPACE Digest V11 #256

Messages from this account are the responsibility of the sender only, and do
not represent the opinion or policy of BT Tymnet, except by coincidence, or
when explicitly so stated.

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
|In article <[e-mail]> [e-mail] writes:
||If you were among the crew of an Earth-originated interstellar flight,
||and made it successfully off this planet of pollution, and warfare, and
||filth, and disease, and death from violence [etc etc etc] ...
|
|Perhaps I should respond in detail to this, but I won't, because I've never
|been able to figure out what to say to someone who hates his own species
|so fiercely and blindly.

Answer: "Jesus loves you".

|--
|With features like this,      |     Henry Spencer at U of Toronto Zoology
|who needs bugs?               | uunet!attcan!utzoo!henry [e-mail]


Phil Nelson . UUCP:uunet!pyramid!oliveb!tymix!pnelson . Voice:408-922-7508
Perhaps the reason the modern liberal so disdains the 2nd amendment, and so
loves the 1st, is that the 2nd protects our right to take action in defense
of liberty, while the 1st protects our right to talk about it.

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

Date: 17 Apr 90 17:26:18 GMT
From: cs.utexas.edu!news-server.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re:  SPACE Digest V11 #256

In article <[e-mail]> [e-mail] writes:
>If you were among the crew of an Earth-originated interstellar flight,
>and made it successfully off this planet of pollution, and warfare, and
>filth, and disease, and death from violence [etc etc etc] ...

Perhaps I should respond in detail to this, but I won't, because I've never
been able to figure out what to say to someone who hates his own species
so fiercely and blindly.
--
With features like this,      |     Henry Spencer at U of Toronto Zoology
who needs bugs?               | uunet!attcan!utzoo!henry [e-mail]

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

Date: 17 Apr 90 20:37:33 GMT
From: sam.cs.cmu.edu![e-mail]  (Vincent Cate)
Subject: Re: Whip launch as first stage?

Vince Cate:
> Can anyone say how much 5 miles of kevlar cable strong
> enough to lift 100,000 lbs would be?  (possible BIG problem here)

I really ment to say that the weight of such a cable could be a big
problem.  I seem to remember something like, "A uniform kevlar cable
X miles long would be able to support its own weight in 1 g."  I
think that X was 50 miles.  If this is the case then a cable strong
enough to lift 100,000 lbs would weigh 2,000 lbs/mile.  Does anyone
know the number for sure?

Another possible problem is the air resistance of the cable.  Can anyone
estimate the drag for a 5 mile long cable with a 0.5 cm diameter
hanging at 45 degrees below the horizon from a plane moving at
600 MPH?   If it takes 200,000 lbs of extra thrust to keep the plane
moving, then a 5 mile long cable is out of the question.  We might
be able to do a good whip with a shorter cable but the accelerations
on the rocket would be greater.

Anyone think we could do a cable 10 miles long?

   -- Vince

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

Date: 17 Apr 90 21:12:28 GMT
From: snorkelwacker!usc!oberon.usc.edu![e-mail]  (Steve Robiner)
Subject: Re: The effects of decompression

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>In article <[e-mail]> [e-mail] (Mark SOKOLOWSKI) writes:
>>I am wondering wheter or not a human body exposed to void would explode,
>
>after a minute or so, but no particular pain is involved, there is no
>explosion, and the effects seem to be fully reversible on recompression.
>

Well, in a similar situation, like SCUBA diving, sudden decompression
from 2 ATMs to 1 can be fatal, if not extremely painful.  This may be
different from 1 ATM to 0, however.

In cases of emergency ascent, subject sometimes become unconscious shortly
after surfacing.  Air embelisms or stroke may result if repressurization
is not implemented imeadiately.  Air bubbles trapped in blood vessels are
extremely painful.

=steve=

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

Date: 18 Apr 90 02:24:08 GMT
From: zephyr.ens.tek.com!wrgate!mrloog![e-mail]  (Dan Tilque)
Subject: Re: Drake Equation (was Re: Interstellar travel)

[e-mail] writes:
>[e-mail] (Dan Tilque) writes:
>>
>> Since we've been listening to the sky at radio frequencies for > 40
>> years now and haven't discovered any alien generated signals, it's
>> probably safe to say that there are no civilizations like ours within
>> that 50 ly radius.  This seems to be better limiting data than the
>> results of the Drake equation.
>
>Who is this "we" that has been listening?  And with what?  These
>signals are not going to be picked up on a boombox with the
>announcement the signal is from outer space.

There's this obscure branch of science which you are probably unaware
of.  It's called Radio Astronomy.  One of the things they're good at is
aiming large radio antennae at the sky.

>I have seen these postings saying that our radio signals have been
>going out for 40 or 50 years.  That puts us back to 1940 or 1950.
>Anyone heard of Heinrich Hertz or Marconi?  80 or 90 years would
>be more accurate.

We didn't really start to send signals in very high strength until TV
and radar were in widespead use in the 40's.  But our sending out
signals is not necessarily connected to our ability to detect an alien
civilization.

>But the point is, we really haven't been
>listening.  It is only in the last decade or two that there have
>been sufficiently sensitive receivers and antennas available to
>listen.  But if these installations picked up such a signal it
>would be mostly accidental.

True they would get it accidentally.  I would assume that a relatively
nearby star which produces unusual amounts of radio frequency for it's
spectral type would be studied by an astronomer.  Also there have been
some programs to listen to a number of nearby stars for unusual
signals.

>On another tack--let's assume there is an intelligent life out
>there about 50 ly.  Let's also even assume their evolution was on
>the same time track.

I never made the assumption that the aliens were exactly even with us
in development.  If they are ahead of us, they are probably easier to
detect, if they are behind us, then your objections are valid.

>The easiest wavelength
>is the same as with us: long waves.  Who is listening below 200
>meters?  Besides which, our earth's atmospheric racket would
>drown out any signals that might possibly be on those frequencies.

There's only so much bandwidth at long wave lengths.  Just like
us, they would soon start using other wavelengths.  Also, long
wavelengths are unsuitable for many uses such as radar.

>But even at UHF and microwave frequencies (which can make it through
>our ionosphere), this is a dauntingly wide spectrum to be
>attempting to cover simultaneously (let alone doing it in all
>directions).

I'm assuming that, like Earth, the aliens produce a large amount of
"waste" radio emissions at many frequencies.  This is the weakest part
of my argument.  If the aliens do little or no general broadcasting, we
may have trouble detecting them.

>It is also a daunting problem to discriminate against
>the signals being caused to be transmitted by ourselves.

One of the steps in processing radio astronomical signals is to filter
out locally generated signals.

>I don't believe it has been proved there is no intelligent
>life within a radius that our radio signals have been going
>out, simply because we haven't heard anything come back we
>could identify as non-earth related.  I pick this time period
>only because we would have to have been detected by some
>intelligent life for this life to direct its antennas at us.

I wasn't talking about intelligent life, I was talking about a
civilization similar to ours.  Let me be slightly more precise: a
civilization which has been using radio extensively for at least 50
years.  But even with these restrictions, you're right, it hasn't been
proven.  It's just strongly indicated.

Why do you assume that we can only detect them if they try to signal us?
The 50 light year limit was somewhat arbitrarily chosen and is not meant
to coincide with the length of time we've been producing strong signals.

>We really haven't been listening.

Actually, Drake and a few others have been listening off and on since the
early 60's.


---
Dan Tilque    --    [e-mail]

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

End of SPACE Digest V11 #277
*******************