Message-ID: <waQ8y8i00VcJQ7sk4v@andrew.cmu.edu>
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Date: Sat,  9 Jun 1990 01:56:26 -0400 (EDT)
Subject: SPACE Digest V11 #511

SPACE Digest                                     Volume 11 : Issue 511

Today's Topics:
		 Janes Spacecraft/Satellites wanted!
	       Hubble Space Telescope Update - 06/08/90
			      Re: Tides
		  Re: HAWAII/ROCKET very long - 61k
			      Re: Tides
		  Re: Ulysses risks II: PuO2 dangers
			   Re: Missing mass
			    Re: Plutonium

Administrivia:

    Submissions to the SPACE Digest/sci.space should be mailed to
  space+@andrew.cmu.edu.  Other mail, esp. [un]subscription notices,
  should be sent to space-request+@andrew.cmu.edu, or, if urgent, to
			 tm2b+@andrew.cmu.edu

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

Date: 8 Jun 90 12:19:33 GMT
From: fernwood!portal!cup.portal.com!Lee_-_Reynolds@decwrl.dec.com
Subject: Janes Spacecraft/Satellites wanted!

Hi.


Would any kind soul/librarian out there have a non-current copy of Janes
SPacecraft/Satellites that they'd be willing to part with for a nominal
fee?


(I'm doing a little tracking and I need a lot of info that Janes seems to
be the only one-stop provider of....)


                            Thanks,

                                       Lee

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

Date: 8 Jun 90 16:26:14 GMT
From: sdd.hp.com!elroy.jpl.nasa.gov!jpl-devvax!jato!mars.jpl.nasa.gov!baalke@ucsd.edu  (Ron Baalke)
Subject: Hubble Space Telescope Update - 06/08/90


                  Hubble Space Telescope Update
                          June 8, 1990
 
     All of the Hubble Space Telescope's instruments were reported to be in
good order, with no problems. The Faint Object Spectrograph (FOS) reports
a pressure of 7e-6 torr and engineering reports that the satellite is 9.9
degrees off optimum power angle.  The Faint Object Camera (FOC) has taken
125 internal images.
 
     Two Wide Field Planetary Camera (WFPC) pictures were taken last night
The field was in Carina, just as the pictures were from June 3 and June 4.
A 10s and a 100s second exposure was taken. The field was supposed to have
been shifted slightly from the June 3 location to bring our one bright star
into the center of PC5, but no slew was put into the system; consequently
the star locations are nearly identical to that of the June 3 exposures (the
stars moved by about 9 pixels).  An additional picture will be taken on
Sunday. Currently, Part 3 of Bootstraph Phase B is in effect.  If this goes
successfully, there will be a secondary mirror movement before the next
picture.  It was discovered that a guide star pair for the WFPC supporting
images may have failed due to a confusing field.  A new guide star pair was
chosen.
 
     A software problem may exist in the Fixed Head Star Tracker (FHST) in
the choice of the reduced field of view (~1 x 1 deg) found within the 8x8 deg
window.  In addition, there are problems with near neighbors and threshold
levels.  In a test yesterday, it was found that 15 out of 60 updates failed
due to confusion with a neighbor star. Another FHST concern is possible
orbital position dependent noise.  Scattered light was suggested as a
possibility for this and a 24 hour test of the FHST was proposed where they
would map the noise as a function of orbital position.  The star catalogue
used by the FHSTs still remains a concern.  The FHSTs on the telescope needs
one star, assuming no neighbors, for its positional verification.  The SMM
satellite was found to use three stars, checked with on-board software.
       _   _____    _
      | | |  __ \  | |       Ron Baalke           |  baalke@mars.jpl.nasa.gov
      | | | |__) | | |       Jet Propulsion Lab   |  baalke@jems.jpl.nasa.gov
   ___| | |  ___/  | |___    M/S 301-355          |
  |_____/ |_|      |_____|   Pasadena, CA 91109   |

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

Date: 8 Jun 90 17:37:19 GMT
From: usc!elroy.jpl.nasa.gov!aristotle!pjs@ucsd.edu  (Peter Scott)
Subject: Re: Tides

In article <1990Jun8.163052.19763@oracle.com>,
fmcwilli@oracle.oracle.com (Floyd McWilliams) writes:

> 	Therefore, the Sun's gravitational pull on the Earth is 177 times
> that of the Moon (divide mass ration by square of distance ratio).
> 
> 	This is what we would expect -- we revolve around the Sun every
> year, not the Moon.  But it seems to me that tides caused by the Sun
> should be 177 times stronger than those caused by the Moon!  What's wrong
> with my reasoning?

Tides aren't caused by absolute gravitational attraction, but by the 
differential attaction on opposite sides of the earth.  Imagine an
inverse-square graph; tides are stronger the steeper the slope.  What
happens to the slope when you get further out?

This is news.  This is your       |    Peter Scott, NASA/JPL/Caltech
brain on news.  Any questions?    |    (pjs@aristotle.jpl.nasa.gov)

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

Date: 8 Jun 90 16:29:20 GMT
From: idacrd!mac@princeton.edu  (Robert McGwier)
Subject: Re: HAWAII/ROCKET very long - 61k

From article <1050400021@cdp>, by jhanson@cdp.UUCP:
> 
> The reason for posting this message here is that there are many
> scientists who are unaware of the enormous environmental
> scientist will start thinking of our planet as a complete system
> instead of a bunch of discrete parts.


I found your submission long and useless.  Give me some scientific citations
so that I might read them for myself and hopefully these will be free of
your emotional arguments.  If you wish to foist an idea upon scientists,
do it with scientific data if you wish them to consider it as scientists.


Bob

-- 
____________________________________________________________________________
    My opinions are my own no matter	|	Robert W. McGwier, N4HY
    who I work for! ;-)			|	CCR, AMSAT, etc.
----------------------------------------------------------------------------

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

Date: 8 Jun 90 22:26:37 GMT
From: usc!cs.utexas.edu!news-server.csri.toronto.edu!helios.physics.utoronto.ca!physics.utoronto.ca!neufeld@ucsd.edu  (Christopher Neufeld)
Subject: Re: Tides

In article <1990Jun8.163052.19763@oracle.com> fmcwilli@oracle.com (Floyd McWilliams) writes:
>
>	The Sun has 27,000,000 times the Moon's mass (the Sun is 333,000
>times more massive than the Earth, which has 81 times the Moon's mass).
>
>	The Sun is 391 times more distant than the Moon (93,000,000 /
>238,000).
>
>	Therefore, the Sun's gravitational pull on the Earth is 177 times
>that of the Moon (divide mass ration by square of distance ratio).
>
>	This is what we would expect -- we revolve around the Sun every
>year, not the Moon.  But it seems to me that tides caused by the Sun
>should be 177 times stronger than those caused by the Moon!  What's wrong
>with my reasoning?
>
   Tides are proportional to the inverse cube of the distance, as they
are related to the spatial derivative of the force. By your numbers this
makes the lunar tides roughly twice the size of the solar tides.

>	Floyd McWilliams -- fmcwilli@oracle.com


-- 
 Christopher Neufeld....Just a graduate student  | He's the kind of person
 neufeld@helios.physics.utoronto.ca              | who'd follow you into a
 cneufeld@pro-generic.cts.com          Ad astra! | revolving door and come
 "Don't edit reality for the sake of simplicity" | out first.

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

Date: 8 Jun 90 14:17:43 GMT
From: att!tsdiag!davet@ucbvax.Berkeley.EDU  (Dave Tiller N2KAU)
Subject: Re: Ulysses risks II: PuO2 dangers

In article <Added.kaPPvSq00UkTMW9E8S@andrew.cmu.edu> HIGGINS@FNAL.BITNET (William Higgins) writes:
>This continues the discussion of the Ulysses probe, its radiothermal
>generators, and their risks.

Where can I get one????   Seriously, as I proposed in a previous article,
this would be an _excellent_ source of heat/hot water for households instead
of nasty petroleum-based sources.  I'd be willing to drop one into my hot
water heater!  Since it'd be easier and more efficient on earth to harness the 
heat generated and convert it to electricity, it might even supply a small
household's power needs, too.  Any conjecture on the feasiblity of this?
What are some of the higher power density fuels available?  Inquirin' minds
gots'ta know!
-- 
David E. Tiller         davet@tsdiag.ccur.com  | Concurrent Computer Corp.
FAX:  201-870-5952      Ph: (201) 870-4119 (w) | 2 Crescent Place, M/S 117
UUCP: ucbvax!rutgers!petsd!tsdiag!davet        | Oceanport NJ, 07757
ICBM: 40 16' 52" N      73 59' 00" W           | N2KAU @ NN2Z

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

Date: 8 Jun 90 23:18:58 GMT
From: uoft02.utoledo.edu!fax0112@tut.cis.ohio-state.edu
Subject: Re: Missing mass


> In article <Added.QaPwDS_00Ui34=sE8v@andrew.cmu.edu> FORTMENU@tudsv1.tudelft.NL ("Nick A. van Goor") writes:
>>
>>The mising matter all exists of disappeared socks.....
>>
>

You can tell its a slow day...

How about an opposing theory a friend I came up with years ago (personally
I think this other one smells!  Someone had to say it, darn it.)
 
The reasoning was like this:

-Most of the matter in the universe is hydrogen
-Therefore most of the missing mass is hydrogen
-Where did it go?
-Where all things like pens, socks and bic lighters all go to when missing
-Since most of the universe is dark, it is dark there too
-When somone finds this place their first reaction will to "flick their bic"
-Is this where the big bang came from?

A case of spherical reasoning!

Robert Dempsey
Ritter Obs.

"The greater the mind the greater the need for play" - Einstein?

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

Date: 9 Jun 90 00:15:00 GMT
From: zaphod.mps.ohio-state.edu!samsung!crackers!cpoint!frog!john@tut.cis.ohio-state.edu  (John Woods)
Subject: Re: Plutonium

In article <14477@thorin.cs.unc.edu>, leech@homer.cs.unc.edu (Jonathan Leech) writes:
> In article <900605082239.21000116@AGCB7.LARC.NASA.GOV> KLUDGE@AGCB7.LARC.NASA.GOV writes:
> >Since Feynman speaks about placing his hands on a warm globe of
> >plutonium, and he lived for a good forty years afterward, I can point out
> >a few excellent examples of how little damage the radiation does.
>     Since Feynman died of cancer, perhaps this is not such a great
> example.  Followups to sci.med.

Feynman died of lung cancer.  He was a heavy smoker.  The conclusion is left
to the student as an exercise.
-- 
John Woods, Charles River Data Systems, Framingham MA, (508) 626-1101
...!decvax!frog!john, john@frog.UUCP, ...!mit-eddie!jfw, jfw@eddie.mit.edu

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

End of SPACE Digest V11 #511
*******************