Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V10_0/V10_064.TXT

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Subject: SPACE Digest V10 #64

SPACE Digest                                      Volume 10 : Issue 64

Today's Topics:
              Re: Neptune fly-by
               Re: Face on Mars
              Re: Neptune fly-by
         NASA Headline News for 09/07/89 (Forwarded)
    Re: Roche Limit, orbits, etc. (was: Progress M-1 ...)
          Hurricane Gabriell GIF pictures from GEOS
          Re: Launch Pad crawler info wanted
             Re: Laser propulsion
          Re: Launch Pad crawler info wanted
                  .
----------------------------------------------------------------------

Date: 7 Sep 89 14:22:08 GMT
From: usc!henry.jpl.nasa.gov!elroy.jpl.nasa.gov!jpl-devvax![e-mail]  (Lee Mellinger)
Subject: Re: Neptune fly-by

In article <[e-mail]> [e-mail] (Kevin Bagley) writes:
:In article <[e-mail]> [e-mail] (Jon Monsarrat "Dr. Who") writes:
:> I was just wondering why the
:>scientific information gathering benefits of leaving the solar system
:>outweigh those of going into orbit around Neptune and shooting some
:>better pictures of the moons. This would have been possible with enough
:>"braking" around Neptune, am I wrong?
:
:   No, you are not wrong, but I don't believe that option was possible.
:   If it had been possible to enter into a Neptune Orbit, I am sure JPL
:   would have opted for this as opposed to exiting the solar system. The
:   main problem here is that Voyager has too much speed, and not enough
:   fuel to do a braking maneuver sufficient to put Voyager into Neptune
:   orbit.  The trajectory past Neptune (Over the northern hemisphere, I
:   believe) was chosen for a close approach of Triton. This also causes
:   Voyager to exit the plane of the solar system.

That is correct.

:
:   Magellan will be a real visual treet.  I can't wait to see the pics
    ^^^^^^^^
      I believe you mean Galileo, Magellan is on its way to Venus as a
      RADAR mapper.

:   it gets of Io, not to mention from the Jupiter Atmospheric probe.
:   Does anybody know what the specs are for how long the probe is
:   expected to last? During atmospheric entry, is ionization going
:   to prevent communications until the chute opens? What atmospheric
:   pressure can the probe withstand? Windspeed?
:
:>-Jon Monsarrat ([e-mail])
:   _____    Kevin Bagley  Global Technology Mukilteo WA 98275 [phone]


Lee

"I'm the NRA"

"They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety." -- Benjamin Franklin 1759

|Lee F. Mellinger                 Caltech/Jet Propulsion Laboratory - NASA
|4800 Oak Grove Drive, Pasadena, CA 91109 818/393-0516  FTS 977-0516
|{ames!cit-vax,}!elroy!jpl-devvax!leem  [e-mail]

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

Date: 7 Sep 89 05:00:07 GMT
From: uhccux!munnari.oz.au!murtoa.cs.mu.oz.au!ditmela!yarra!melba!baby![e-mail]  (Gregory N. Bond)
Subject: Re: Face on Mars

In article <[e-mail]> [e-mail] (Timothy D Margeson) writes:

   About computer enhancement of images... With some images, blurred especially,
   computer enhancement can make astoundeing improvements, with all the accuracy
   one wants, so long as you have a statistically sound sample to begin with.

And you have some idea of what you're looking at.

   The images that come to mind that were most striking was that of a license
   plate on the back of a VW bug. The original photo was taken as a bank robbery
   suspect fled the scene of a crime, and a person who was standing near by
   holding a camera snapped a photo hurriedly.

   The photo was thought to be hopelessly blurred due to camera motion - I sure
   couldn't tell what was in the original photo - but the detectives contacted
   a specialty firm, had enhancements done and they were able to reconstruct
   the original image to a detail sufficient to read the license plate number!!

The difference is that the police knew it was a VW, they knew how big
it is, how fast and in which direction it was moving.  This makes it
quite easy to reconstruct.  In fact, the reconstruction is designed to
extract the information the police already knew was there.

In the case of the Mars "face", all we KNOW is that it is a patch of
dirt.  If we assume it has symmetry, is a face, is artificial, then
this will guide our reconstructions and low and behold, we see a face.
If we accept we know nothing about its real form or nature, the amount
of processing we can validly do is limited (remove noise, contrast
enhance etc).  Doing image analysis using the model that assumes a
symmetric artificial construction _ought_ to lead to symmetric
artificial results!

Greg, not an image processing person, not a believer in men from mars.

--
Gregory Bond, Burdett Buckeridge & Young Ltd, Melbourne, Australia
Internet: [e-mail]    non-MX: [e-mail]
Uucp: {uunet,pyramid,ubc-cs,ukc,mcvax,prlb2,nttlab...}!munnari!melba.bby.oz!gnb

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

Date: 7 Sep 89 12:30:18 GMT
From: [e-mail]  (Terry Hancock)
Subject: Re: Neptune fly-by

In article <[e-mail]> [e-mail] (Kevin Bagley) writes:
>
>   Magellan will be a real visual treet.  I can't wait to see the pics
>   it gets of Io, not to mention from the Jupiter Atmospheric probe.

    Uh, that's *Galileo* you're thinking of.  Magellan is the
Venus Orbiting Imaging Radar project, also very interesting, but
not going to Jupiter.
    Curiously enough, though, Galileo WILL go to Venus on its way
to Jupiter.  If I'm not mistaken, Galileo will beat Magellan to Venus
despite its later launch, since it will have a higher encounter velocity
for gravity assist reasons (while Magellan will have a low encounter
velocity, allowing it to be captured into Venus orbit).
    Of course, I'm not sure about that -- somebody posted a timeline,
it's probably got it right.
>
    Sorry to be picky,   :-)



*********************************
Terry Hancock
[e-mail]
*********************************

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

Date: 7 Sep 89 18:51:35 GMT
From: trident.arc.nasa.gov![e-mail]  (Peter E. Yee)
Subject: NASA Headline News for 09/07/89 (Forwarded)

-----------------------------------------------------------------
                          NASA Headline News
Thursday, Sept. 7, 1989                       Audio: 202/755-1788
-----------------------------------------------------------------

This is NASA Headline News for Thursday, September 7....


Aerospace Daily reports that the European Space Agency, Japan and
Canada told NASA tuesday they expect the United States to live up
to its agreement with them before deciding how to downscale the
Space Station.  The publication says NASA is facing a possible
budget cut of $400 million in the Space Station Freedom program.

Space Station officials are meeting with industry and
international representatives today and tomorrow to outline a
descoping plan put together this summer.  Aerospace Daily says
the international partners have indicated concern over not being
included in the descoping plan which would cut space station crew
size in half....reduce electrical power capability by 50
percent...cut provisions for attached payloads and modify the
life-support system.


Meanwhile....Two Soviet cosmonauts are scheduled to board the Mir
Space Station early tomorrow.  The station has been unmanned for
the past four months because of reported technical problems and
budgetary constraints.  The Soviets will add two modules soon
that will increase work space by about 550 cubic feet.  The first
module will be launched in October followed by the second in
February.


Rockwell International will team with Honeywell, Mcdonnell
Douglas Space Systems and TRW Federal Systems to compete for a
study contract of the Space Station Emergency Return Vehicle.
Lockheed Missiles and Space and Boeing Aerospace are also teaming
up to compete for the contract.


Launch Pad 39 B is cleared of all but essential workers today as
technicians replace a solid rocket igniter seal on the right hand
SRB.  The igniter seal on the left hand SRB will be replaced on
Saturday.  Tomorrow, pad workers will carry out the Galileo
payload end-to-end test.

And...Hurricane Gabrielle continues to move in a northerly
direction and now appears to no longer be a threat to the U.S.
East Coast.




                *             *         *         *


-----------------------------------------------------------------
Here's the broadcast schedule for public affairs events on NASA
Select television.  All times are Eastern.


Thursday, September 14......

   11:30 A.M.       NASA Update will be transmitted.


Friday, September 15......

   6:00 A.M.        STS-34 Countdown Demonstration Test from KSC
                    continues through 12 noon.

All events and times are subject to change without notice.
-----------------------------------------------------------------
These reports are filed daily Monday thorough Friday at 12 noon,
Eastern time.
-----------------------------------------------------------------

A service of the Internal Communications Branch (LPC), NASA
Headquarters.

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

Date: 8 Sep 89 15:34:06 GMT
From: jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Roche Limit, orbits, etc. (was: Progress M-1 ...)

In article <[e-mail]> [e-mail] (William Lewis) writes:
>>More refined treatments, as I recall, conclude that when the satellite
>>is below a certain size (determined by the gravity gradient of the primary
>>and typical satellite mechanical properties, I assume), there is no Roche
>>limit.
>
>   Or rather, the Roche limit is below the surface of the planet...

Which means there is no Roche limit, period.  Below the surface, the
gravitational field begins to diminish because of the mass above you.
You can have a Roche limit below the surface only if most of the mass
is concentrated in the central core, which isn't true of normal planets.
(What W.L. undoubtedly meant is that if you consider the planet a point
mass for gravitational purposes, the Roche limit is below where the
surface really is.)
--
V7 /bin/mail source: 554 lines.|     Henry Spencer at U of Toronto Zoology
1989 X.400 specs: 2200+ pages. | uunet!attcan!utzoo!henry [e-mail]

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

Date: 8 Sep 89 21:10:06 GMT
From: ux1.cso.uiuc.edu![e-mail]  (Phil Howard)
Subject: Hurricane Gabriell GIF pictures from GEOS

Current GEOS weather satellite images showing Hurricane Gabriell and other
weather activity in GIF format are being placed online for anonymous FTP
access.

host:       vmd.cso.uiuc.edu (128.174.5.98)
user:       anonymous
pass:       -none-
cd/cwd:     phil.515
--

--Phil howard--  <[e-mail]>
_.__ . ...   _ ... .. ...   .. ...   __ _.__
._._._ ... .. __. _. ._ _ .._ ._. .   .._. .. ._.. .

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

Date: 8 Sep 89 16:12:22 GMT
From: mcsun!ukc!icdoc!syma![e-mail]  (Nick Watkins)
Subject: Re: Launch Pad crawler info wanted

In article <[e-mail]> [e-mail] (Henry
Spencer) writes:

>The place you want to look for gobs of information on this beast, and a lot
>of the other KSC support facilities, and how they got the way they are, is
>"Spaceport", one of the three big Apollo-related books in the NASA History
>series.
If "Apollo Expeditions to the Moon" is one, what is the third?

Nick





--
Nick Watkins, Space & Plasma Physics Group, School of Mathematical
& Physical Sciences, Univ. of Sussex, Brighton, E.Sussex, BN1 9QH, ENGLAND
JANET: [e-mail]   BITNET: [e-mail]
Voice: [phone]

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

Date: 9 Sep 89 02:49:03 GMT
From: mailrus!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Laser propulsion

In article <[e-mail]> [e-mail] (George Michaelson) writes:
>As for increased laser SIZE surely the requirement is for increased
>ENERGY at the point of "combustion" in which case banks of lasers might
>suffice. Building many smaller lasers being (probably) more simple than
>1 mega-huge one...

In practice, most any big laser would probably be built as a bunch of
smaller modules.  "Size" in this context means "power".  There are some
problems in making all the modules work together, but it's easier than
building humongous single lasers, and there are fewer single-point
failure modes.
--
V7 /bin/mail source: 554 lines.|     Henry Spencer at U of Toronto Zoology
1989 X.400 specs: 2200+ pages. | uunet!attcan!utzoo!henry [e-mail]

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

Date: 9 Sep 89 02:58:47 GMT
From: mailrus!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Launch Pad crawler info wanted

In article <[e-mail]> [e-mail] (Nick Watkins) writes:
>>"Spaceport", one of the three big Apollo-related books in the NASA History
>>series.
>If "Apollo Expeditions to the Moon" is one, what is the third?

AEttM isn't in that series.  The NASA History books are big fat volumes with
lots of historical and sometimes technical detail.  AEttM is aimed more at
the general public, and is heavy on glossy photos and light on fussy detail.
(It's a good book, mind you, and worth having, but of a different kind.)
The three NASA History books about Apollo are "Moonport" (what I was really
thinking of when I wrote the above), "Chariots for Apollo" (not to be
confused with Pellegrino's book of the same name), and "Stages to Saturn".
NASA SP-4204, SP-4205, and SP-4206 respectively.  These are excellent books.
Actually, almost anything in the series is worth having; some others are "On
Mars" (Viking; SP-4212) and "Living and Working in Space" (Skylab; SP-4208).
These books are written by professional historians with unlimited access to
relevant NASA documents.  Now, mind you, they do tend to give you the
Official NASA Viewpoint on controversial issues -- for example, you will
not find a straight account of the third Skylab crew going on strike in
LaWiS -- but there's still a lot of stuff in them that you will never find
in popular accounts.
--
V7 /bin/mail source: 554 lines.|     Henry Spencer at U of Toronto Zoology
1989 X.400 specs: 2200+ pages. | uunet!attcan!utzoo!henry [e-mail]

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

Date: 10 Sep 89 12:00:26 GMT
From: cdp![e-mail]
Subject: .


This is the National Space Society's Space Hotline for the week  of September 8th.    As congress returns this week, the Senate subcommittee on VA, HUD
and Independent Agencies will take up the NASA appropriations  bill. NASA's request of 13.274 billion has already been cut by 1
billion in the House, resulting in $395 million less for the  space station program. Subcommittee chairman, Sen. Barbara
Mikulski of Maryland, has scheduled the vote on the NASA budget
for next Tuesday, Sept. 12th.

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

End of SPACE Digest V10 #64
*******************