Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V13_1/V13_155.TXT

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Subject: SPACE Digest V13 #155

SPACE Digest                                     Volume 13 : Issue 155

Today's Topics:
               Re: Science as Religion
         Space Shuttle Endeavor...Need Info.
              Magellan Update - 02/12/91
    Re: German satellite to begin U.S. science mission (Forwarded)
               Magellan article
              Galileo Update - 02/11/91
                   dynasoar
      Re: Kevlar (was:  Manoeuvring using rope and anch

Administrivia:

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Date: 23 Jan 91 13:53:26 GMT
From: csus.edu!wuarchive!swbatl!wuarchive!sdd.hp.com!uakari.primate.wisc.edu!aplcen!sun4![e-mail]  (James W. Meritt)
Organization: Johns Hopkins University Applied Physics Laboratory
Subject: Re: Science as Religion
References: <[e-mail]>, <[e-mail]>, <[e-mail]>
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In article <[e-mail]> [e-mail] (Paul M. Koloc) writes:
}In article <[e-mail]> [e-mail] (Kent Sandvik) writes:
}>In article <[e-mail]> [e-mail] (Pete Yadlowsky) writes:
}>>>An open minded scientist may speculate that someone organized the universe.
}
}>We have this age-old mythological scene where people belive that
}>everything has to be created, by someone else... .  and for instance
}>quantuum mechanics shows us how particles suddenly appear from nothing,
}> .. .
}
}Huh???   What?  Pray you tell, "WHAT PARTICLE is created 'from nothing',
}quantum mechanics or not ???"  Are you a Joe Newman follower?
}
}and .. describe "particle" if you do answer.

See also "virtual particles" and "Hawkins radiation".

}>It will take some time before the acceptance of an idea such as a
}>self-contained universe will be more widespread.
}
}Seeing as how energy is conserved and we are in a low energy density
}dimensional state (limited information in a high order universe), I
}would say you may not have a good working model (concept) of the total
}physical universe let alone what ever the whole of REALITY is.

Oh, really?  Why not read up on vacuum energy?  The Joural of British
Interplanetary Society had a very interesting article on how it may
be used forInterstellar flight.  A unquantified "energy is conserved"
is wrong.  Ask, for instance, Japan.

}> == self contained ==
}
}I thought studies show our physical (3D) universe is "open".  I think
}that means it could have disconnected islands.  It depends on how
}you conceptual the metric.  Did the metric pre-exist (was it defined
}in the conditions prior to) the Big Bang?

Within this last week I read they were still looking, and the article
was within the context of the "cold dark matter" tests.  You have
better information?


BTW:  Yep, I know about the bubble universes...



Opinions expressed are solely those of the author, and do not necessarily
represent those opinions of this or any other organization.  The facts,
however, simply are and do not "belong" to anyone.
    [e-mail] or [e-mail] or meritt%aplvm.BITNET

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Date: 11 Feb 91 01:08:44 GMT
From: [e-mail]  (Russell J. Soots)
Organization: Computer and Technologies Theme Program
Subject: Space Shuttle Endeavor...Need Info.
Sender: [e-mail]
To: [e-mail]


   I need as much information as possible about the new space shuttle
Endeavor.  Similarities and differences with the current shuttles, first
scheduled launch and mission, cost, details of its construction (esp.
beginning date), etc.  Pleae e-mail any relevant info to me ASAP.  I must
have the information by Feb. 14th.  Thanks in advance!

                                                 'happy'
                                                    RJS


--
*******************************************************************************
RUSSELL J. SOOTS - North Carolina State Univesity - SED+BCH, minor GN
[e-mail]_______________________North Carolina Teaching Fellow
*******************************************************************************

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Date: 12 Feb 91 20:55:59 GMT
From: usc!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
Subject: Magellan Update - 02/12/91
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                         MAGELLAN STATUS REPORT
                           February 12, 1991

     On Monday, February 11, Magellan engineers noted that the temperatures of
the spacecraft battery compartment have continued to increase during the
mapping portion of each orbit, reaching a maximum of 25 degrees Celsius.
This continued, slow increase is occurring even though the incidence angle of
the Sun on the battery compartment is decreasing.  Two explanations have been
postulated:

        o The battery compartment is being illuminated by specular
          reflection of sunlight from the solar panels; or

        o The exterior of the battery compartment is turning darker
          with exposure to the Sun, increasing the percentage of
          the Sun's heat absorbed.

     The battery temperature alarm limit, designed to protect against a
failed-on battery heater, is currently set at 28 degrees.  At 32 degrees,
spacecraft fault protection would disconnect the overheated battery from the
spacecraft electrical power system, and relying only on the backup battery.

     In order to keep the battery temperatures within acceptable limits, the
Project has decided to shorten the period of mapping on alternate orbits by
turning the spacecraft to point the High Gain Antenna toward Earth ten minutes
earlier than the nominal mapping orbit.  This decrease in mapping time will
cause a 10 minute loss of radar date on "delayed swath" orbits, when the radar
data is collected further south, and the decrease in mapping time will
therefore decrease the southerly extent of the mapping coverage from 78 to 52
degrees south latitude.  Immediate swath orbits are not affected by this early
turn to Earth point.

     Various approaches to controlling the spacecraft temperatures were
analyzed.  Several were discarded because of difficulties in preparing the
command sequences or in processing the resulting radar image data.  This method
of decreasing heating was chosen because it can be implemented quickly without
special modifications to the normal command sequence.  The changes in orbit
timing will be carefully verified in the Systems Verification Laboratory, then
transmitted to the spacecraft today to take effect tomorrow.

     The shortened mapping pass will be reassessed on February 14 for possible
increase or decrease based on the observed temperatures.  The heating is
expected to be alleviated in about two weeks when the spacecraft again begins
to pass through the shadow of Venus during its mapping period.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|      Ron Baalke         | [e-mail]
     | | | |  __ \ /| | | |      Jet Propulsion Lab | Is it mind over matter,
  ___| | | | |__) |/  | | |___   M/S 301-355        | or matter over mind?
 /___| | | |  ___/    | |/__ /|  Pasadena, CA 91109 | Never mind.
 |_____|/  |_|/       |_____|/                      | It doesn't matter.

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

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Date: 14 Feb 91 05:46:21 GMT
From: zephyr.ens.tek.com!tektronix!sequent![e-mail]  (Nick Szabo)
Organization: Sequent Computer Systems, Inc.
Subject: Re: German satellite to begin U.S. science mission (Forwarded)
References: <[e-mail]>, <[e-mail]>
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In article <[e-mail]> [e-mail] (Daniel Fischer) writes:
>In article <[e-mail]> [e-mail]
>(Peter E. Yee) writes:
>>Michael J. Braukus
>>Headquarters, Washington, D.C.                        February 11, 1991

>>While these problems are
>>still being analyzed, they are not expected to impact the science
>>mission...

[Mr. Fischer states specific problems and workarounds, and how
these do indeed greatly impact the science mission]

>Why can't NASA simply tell that story ?

NASA is a political agency, and its postings to the net reflect its
desire for more revenues.  This is not so different from companies
announcing and commenting on their products in the various comp.*
newsgroups, except that NASA seeks political support, not voluntary
purchases.  Any information posted from NASA should be regarded with
the same caution one regards news coming from the government agencies
(U.S. and foreign) involved in the Iraq war.  It is often not the
complete picture.


--
Nick Szabo            [e-mail]
Embrace Change...  Keep the Values...  Hold Dear the Laughter...

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Date: 14 Feb 91 22:43:27 GMT
From: elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
Subject: Magellan article
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Associated Press -- 2/14/91
"Venus Volcanoes"
By Lee Siegel

"Some volcanoes on Venus erupt explosively and spew ash
skyward, unlike the planet's typical volcanoes, which gently
produce lava flows, the Magellan spacecraft has found."

The AP Los Angeles science writer says that although
Magellan hasn't yet caught a Venutian volcano in the act of
spewing forth material, it has found signs, in the radar
imagery it is sending back, of Venus' landscape that strongly
suggest earlier volcanic blasts.  The story says these appear as
ash deposits in various regions.

The report notes that Venus lacks water which would erode
away the surface to acquire the ash-strewn look, and the winds
on the planet are sluggish enough so that there is no wind-
caused erosion either.  Given these two predicates, the story
says the Magellan scientific team has concluded that what
they are seeing are, in fact, the ash remains of volcanic
eruptions.

The story says that in some cases, the ash appears to be
deposited as much as six miles from its probable source.  The
report says that, as of now, Magellan has mapped slightly over
half of the surface of Venus.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|      Ron Baalke         | [e-mail]
     | | | |  __ \ /| | | |      Jet Propulsion Lab | Is it mind over matter,
  ___| | | | |__) |/  | | |___   M/S 301-355        | or matter over mind?
 /___| | | |  ___/    | |/__ /|  Pasadena, CA 91109 | Never mind.
 |_____|/  |_|/       |_____|/                      | It doesn't matter.

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

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Date: 11 Feb 91 16:58:54 GMT
From: van-bc!ubc-cs!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
Subject: Galileo Update - 02/11/91
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                        GALILEO STATUS REPORT
                          February 11, 1991

     The Galileo spacecraft's health continues to be excellent.  Yesterday,
Galileo successfully performed the planned sun acquisition activity.  Today,
no spacecraft activity is planned.  Tomorrow, a USO (Ultra Stable Oscillator)
test and a sun acquisition are planned.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|      Ron Baalke         | [e-mail]
     | | | |  __ \ /| | | |      Jet Propulsion Lab |
  ___| | | | |__) |/  | | |___   M/S 301-355        | It's 10PM, do you know
 /___| | | |  ___/    | |/__ /|  Pasadena, CA 91109 | where your spacecraft is?
 |_____|/  |_|/       |_____|/                      | We do!

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Date:    Thu, 14 Feb 91 04:35 EST
To: [e-mail]
From: Mike Bishop                          <[e-mail]>
Subject: dynasoar




 Can anyone tell me what ever became of the Dynasoar project?
 Did it just fade away, or is there ongoing work on the
 lifting body concept?

 Was this an Air Force endevor?
 It seems this was some sort of forerunner of the Shuttle.
 And if this project has been abandoned where might one go to
 see any of the aircraft on display, if this possible?

 thanks,
 mike

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Date: 14 Feb 91 15:55:16 GMT
From: news.miami.edu!rcf.rsmas.miami.edu![e-mail]
Subject: Re: Kevlar (was:  Manoeuvring using rope and anch
References: <[e-mail]>
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In article <[e-mail]>,
          [e-mail] (John Prentice) writes:
[...]
> when repeatedly bent or even when tied in a knot.  Put another way, yes,
> it has a high tensile strength in uniaxial tension, but it does not have
> as high a shear strength (as I recall from the controversy of few years
> ago, maybe someone can speak to this who knows more than I do about it).
>
> One thing about using something like Kevlar for a cable that is going
> to have to absorb a shock.  It doesn't stretch all that much, so the
[...]
Another perspective on Kevlar from a practical application: For many years
oceanographers have used Kevlar in deep water moorings. A mooring typically
consists of a string of instruments attached to a line with flotation at the
top (and sometimes at imtermediate points) and an anchor (typically old
railroad wheels) on the bottom. The line to which everything is attached is the
crucial load-bearing element. In addition, it is also the element which, when
integrated over the whole length of the mooring, accounts for the vast majority
of the horizontal drag in the presence of ocean currents. That drag tends to
make the mooring lean over which is very undesirable from a measurement
standpoint. So, one wants a line which is both strong enough to handle the
axial tension and yet is as small in diameter as possible to reduce drag. Wire
rope was the choice for decades. More recently, Kevlar was used but only with
varying degrees of success. Moorings are deployed from ships top first - that
is, the whole thing gets strung out on the surface of the ocean and then the
anchor gets kicked over and the whole show sinks vertically. It is at that
anchor release time that the line experiences maximum tension. Many have broken
on deployment since Kevlar cannot stretch  as much as wire rope. In addition,
there is evidence that small nicks in the Kevlar can significantly reduce
strength. And,  last but not least, sharks seem to like to bite it.

-------------------------------------------------------------------------------
Jerry L. Miller  /\         Rosenstiel School of Marine and Atmospheric Science
#\      o   O    \/     /\  University of Miami
#/ /\/\/\/\/\/\/\/\/\  /    4600 Rickenbacker Cwsy.
/ /   o       O      \/     Miami, FL 33149  USA
Phone: [phone]      INTERNET:  [e-mail]

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End of SPACE Digest V13 #155
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