Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V12_6/V12_651.TXT

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Subject: SPACE Digest V12 #651

SPACE Digest                                     Volume 12 : Issue 651

Today's Topics:
           ASTRO mission status at 5/10:30
              Question on tidal locking.
  Re: Press briefing on Augustine Committee final report (Forwarded)
            Re: Planetary Society
         Re: Shuttle Status for 12/06/90 (Forwarded)
           Re: ASTRO status at 4/16:00 MET
              Re: Another Russian first
        UIT Status for 12/07/90 [1600 CST] (Forwarded)
             Re: * SpaceNews 03-Dec-90 *

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

Date: 7 Dec 90 17:17:27 GMT
From: uvaarpa!murdoch![e-mail]  (Greg Hennessy)
Subject: ASTRO mission status at 5/10:30

The UV instruments on the ASTRO observatory are again taking data.
Shift 10 had essentially no science done with the three UV
instruments, while the BBXT continue to take data. While the first two
orbits of Shift 11 did not have any sucessful acquisitions, UIT
obtained three deep exposures of NGC 1399, and WUPPE and HUT also got
data on this galaxy. Later HUT was able to obtain lots of data on the
quasar Q1821, and two orbits later WUPPE wa sback in business by
itself as it obtained the star Gamma Gem on its own. The astronauts
are tracking the stars by using a joystick, and they have about 5
arcsecons of jitter, which is acceptable to HUT and WUPPE (they have
large slits) and the Image Motion Compensator is working to keep UIT
stable to about a tenth of an arcsecond. The philosophy of the
misssion has changed a bit, to get longer observations of fewer
targets, since the overhead per observation is greater than expected.
This makes UIT very happy, since they get nice deep exposures to work
with.

Here is a breakdown of the shift number, observing time scheduled, and
acutally obtained, times in minutes.

Shift    Scheduled    Obtained    Percentage    Notes
6    345         54        17
7    418        163        38        Startracker patched
8    429        189        44
9    428        247        57
10     36          8         4        2nd DDU died
11    343        187        55

The prelaunch expectations were that about 80 percent of the time
scheduled would be observed, so while we are not there yet, we are
gettin gcloser. There may be a 11'th day of the mission, which would
allow us to recover some of the lost time due to the problems with
spacelab.
--
-Greg Hennessy, University of Virginia
 USPS Mail:     Astronomy Department, Charlottesville, VA 22903-2475 USA
 Internet:      [e-mail]
 UUCP:        ...!uunet!virginia!gsh7w

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

Date: 7 Dec 90 17:54:51 GMT
From: [e-mail]  (Rogers)
Subject: Question on tidal locking.



Hope somebody out there can settle a question about tidal locking.

When the tidal locking process has run its course, will the rotational axis
of the satellite be perpendicular to the plane of its orbit about its primary?

This question was generated by Isaac Asimov's _Nemesis_, in which he
describes a stellar system composed of a red dwarf star called Nemesis, a
single gas giant planet called Megas, and a single moon of the gas giant,
called Erythro.

Here's an excerpt from the posting which started all this:

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

On pg. 78 of the paperback edition, a character says of Erythro,
"'... [due to tidal lock] only one side faces Megas, which is much cooler
than Nemesis. Furthermore, the satellite's orbit is tilted substantially
to Megas' equator. This means that in the satellite's sky, Megas is seen from
only one hemisphere and it moves north and south with a cycle of about one day,
while Nemesis moves across the sky, rising and setting, again with a cycle of
one day. One hemisphere has twelve hours of darkness and twelve hours of light.
The other hemisphere has the same but during its daytime, Nemesis is frequently
in eclipse for up to half an hour at a time, with the cooling made up for by
Megas' mild warmth. During the dark hours, in that hemisphere, the darkness is
ameliorated by Megas' reflected light.'"

Now, forgive me if there's something simple that I'm not getting here, but
I can't see how Megas can move north and south in Erythro's sky if one side
of Erythro permanently faces Megas. Especially if this has come about via
tidal lock.

Furthermore, Asimov implies that Megas moves north and south in Erythro's sky
BECAUSE of the fact that Erythro's orbit is inclined relative to Megas'
equator. But in fact there is no such causal connection. The only thing that
would cause Megas to move north and south in Erythro's sky is if Erythro's
axis were not perpendicular to the plane of Erythro's orbit about Megas. And
the angle between a satellite's axis and its orbit is independent of
the angle between the satellite's orbit and its primary's equator.

However, doesn't the mechanism of tidal lock basically guarantee that a
satellite's axis WILL be perpendicular to the plane of its orbit? I.e., the
same mechanism that acts to slow the satellite's revolution with respect to
its primary will also act to slow the rotational oscillations that would give
rise to the described north & south movement of the primary as seen from the
satellite.

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

Thanks in advance for any help.       --- Jeff R.

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

Date: Fri, 7 Dec 90 16:45:01 -0500
From: "Allen W. Sherzer" <[e-mail]>
Subject: Re: Press briefing on Augustine Committee final report (Forwarded)
Newsgroups: sci.space
Cc:

In article <[e-mail]>:

>PRESS BRIEFING ON AUGUSTINE COMMITTEE FINAL REPORT

There is also an article on this in today (Friday')s Wall Street Journal
on the back of section 1. Among the recommendations are:

1. Less reliance on the Shuttle

2. Build a new launcher. This looks like ALS but they didn't call it that.
   This new launcher can be configured to launch various payloads and will
   cost $10B to develop.

3. Reorganize the centers so that each has a well defined area of expertise.
   This will prevent duplication of effort so more work can be done for less
   money.

4. Drop plans to build a new Shuttle and use the money for this new launcher.




And now, my editorial comments:

1. Don't build the launcher they are talking about. For the cost of the new
   orbiter we can build two different HLV's using existing designs AND have
   a good chunk left to build capsules.

2. The reorganizaiton is good as far as it goes but more is needed.
   Operational responsibility however, must be taken away from NASA and
   turned over to the private sector.

It would have been interesting to see the documents which went into the
final version. The recommendations released where the consensus view of
the panel and there where many who held stronger (and weaker) views.

However, it is likely that the House will begin its own hearings into
NASA. They are looking to make much more radical changes than proposed
here. It should be an interesting year.

  Allen
--
+---------------------------------------------------------------------------+
|Allen W. Sherzer| I had a guaranteed military sale with ED-209. Renovation |
|   [e-mail]  | programs, spare parts for 25 years. Who cares if it      |
|                | works or not?  - Dick Jones, VP OCP Security Concepts    |

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

Date: Fri, 7 Dec 90 18:39:10 EST
From: John Roberts <[e-mail]>
Disclaimer: Opinions expressed are those of the sender
    and do not reflect NIST policy or agreement.
Subject: Re: Planetary Society


>From: zephyr.ens.tek.com!tektronix!sequent!crg5![e-mail]  (Nick Szabo)
>Subject: Re: space news from Oct 6 AW&ST

>In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>>
>>Planetary Soviety invitation-only meeting to "critique" the current space
>>station...
>>...(On the other hand,
>>some of the attendees commented that the deck was stacked:  the choice
>>of participants seemed to be deliberately aimed at such a conclusion.)

>Isn't "invitation only" also true of NASA commitees, the Space Council,
>NSS commitees, etc.?  Your biases are showing, Henry.  :-)

The stated purpose of the meetings should be taken into account. If NASA is
seeking external input to its own project, it may reserve the right to
concentrate on the advice of those whose knowledge and judgement it has
come to respect. (It should not, however, refuse to accept input from
others. NASA conducted a program a few months ago soliciting ideas from the
general public.)

If the Planetary Society wants to produce a consensus statement of people
who hold a particular point of view, then fine. If they want to produce a
statement and claim that it is the general consensus of everyone in the
field, then they shouldn't make a deliberate effort to stack the meeting
with people known to hold a particular point of view.

My own opinion is that the space station was in need of redesign, particularly
in light of the predicted need for maintenance during assembly. I would also
consider at least the option for use as an assembly point for lunar and
interplanetary craft to be very important.

>It is about time the man-in-space people started listening to the
>Planetary Society folks.  While NASA has wasted most of its money on
>earth-orbiting manned projects, the Planetary Society (many of them
>ex-Voyager and Viking project people) have quietly pushed the
>continuation of our U.S. program that has explored most of the planets
>and moons in the solar system, with only a tiny fraction of NASA's
>budget.  This, and the development of the first and largest commercial space
>industry (unmanned communication satellites) have put the U.S. far
>ahead of any other country in space, yet we squander this with attention
>and money lavished on dead-end manned projects.

Last I heard, the Planetary Society was still pushing for a hideously
costly, crash-priority one-shot manned trip to Mars, mainly to serve
as an inspiration to mankind and generate political goodwill, and at the
expense of most or all other manned space activity for the forseeable
future. I do not consider this a good utilization of human resources in space,
and since I have read claims that the Planetary Society in its lobbying
tends to imply that *all* its members support the "official" view, I have
avoided joining the Planetary Society in spite of its many excellent
features.

Perhaps this "outsider's" view is overly biased, and a member could give
a more accurate perspective.
         John Roberts
         [e-mail]

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

Date: Fri, 7 Dec 90 11:07:26 -0500
From: "Allen W. Sherzer" <[e-mail]>
Subject: Re: Shuttle Status for 12/06/90 (Forwarded)
Newsgroups: sci.space
Cc:

In article <[e-mail]>:
>So here's the $6e6 question for the day: What's going to happen to Astro
>when it gets back to Florida?

I wonder if anybody has considered putting it on Freedom? That way people
could do observations during spare time or as part of the regular schedule.

Of course, this assumes that there will be a space station which may not
be a good bet the way the redesign is going. :-(

  Allen

--
+---------------------------------------------------------------------------+
|Allen W. Sherzer| I had a guaranteed military sale with ED-209. Renovation |
|   [e-mail]  | programs, spare parts for 25 years. Who cares if it      |
|                | works or not?  - Dick Jones, VP OCP Security Concepts    |

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

Date: 7 Dec 90 16:14:20 GMT
From: uvaarpa!murdoch!astsun.astro.Virginia.EDU![e-mail]  (Greg Hennessy)
Subject: Re: ASTRO status at 4/16:00 MET

Harry P Bloomberg writes:
#   Now get back to work and fix those *&(*&^% star trackers! :-) :-) :-)

They won't. The astronauts do a good enough job, and the better
stability that the star trackers give us is not worth the lost time
that they cause. The astronauts are doing better than expected, and
the machines worse.

When I get some sleep (right now I won't catch up on sleep till about
the 15th) I'll probably consider the implications of that statement.

--
-Greg Hennessy, University of Virginia
 USPS Mail:     Astronomy Department, Charlottesville, VA 22903-2475 USA
 Internet:      [e-mail]
 UUCP:        ...!uunet!virginia!gsh7w

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

Date: 7 Dec 90 01:01:57 GMT
From: uokmax!munnari.oz.au!bruce!monu1!monu6!minyos![e-mail]  (Glen Pill)
Subject: Re: Another Russian first

From article <[e-mail]>, by [e-mail] (John A. Weeks III):
> In article <[e-mail]> [e-mail] writes:
>
> Interesting to note that the Soviets have had a string of workable space
> stations, while Skylab 2 is sitting inside of the National Air & Space Museum.
>

I always thought skylab was splattered over Western Australia.

 :-)


--
Glen Pill                              ACSNet: [e-mail]
RMIT Computer Centre                   Snail : 124 LaTrobe St, Melb. Oz. 3000.
                                       Phone : [phone]

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

Date: 8 Dec 90 05:21:27 GMT
From: trident.arc.nasa.gov![e-mail]  (Peter E. Yee)
Subject: UIT Status for 12/07/90 [1600 CST] (Forwarded)


         UIT Status Report #05
         4 p.m. CST Dec. 7, 1990
         Spacelab Mission Operations Control
         Marshall Space Flight Center
         Huntsville, AL


         Principal Investigator Ted Stecher and other members of the
         Ultraviolet Imaging Telescope Team worked even harder than usual, with
         ground command of their instrument added to their normal duties.  But,
         "I'd even say that commanding from the ground is fun," said UIT member
         Barbara Pfarr.

         Targets observed today by UIT included the cluster of galaxies Abell
         2597, Supernova 1987A, and the Andromeda galaxy (M31).

         UIT was developed at Goddard Space Flight Center in Greenbelt, MD.

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

Date: 9 Dec 90 19:47:43 GMT
From: usc!cs.utexas.edu!ut-emx![e-mail]  (Srinivas Bettadpur)
Subject: Re: * SpaceNews 03-Dec-90 *

In article <[e-mail]> [e-mail] (Franklin Antonio) writes:
>> [e-mail] (Bill Newman) writes:
>>> [e-mail] (Henry Spencer) writes:
>>>> [e-mail] (Franklin Antonio) writes:
>>>>So, the basic work was done 371 years ago!  This is one of the humbling
>>>Kepler is not the really humbling example in celestial mechanics.  That
>>>honor goes to Isaac Newton, ...
>>>mathematicians of the next two centuries basically just added footnotes
>>>to his work.
>
>I agree with Henry.  Newton humbles us all.  As for the following 370 years of
>many-body perturbation and stability theory: bah!  "plausible" and "could be"
>are waffle-words.

   While I will agree that Newton established all the fundamentals for
the CM, that he did grind the 2-body problem to dust, and that the
science of CM is indeed four centuries old, I cannot agree to calling
the later work "footnotes" or dismissing the following works as being
un-verifiable.
   This argument is similar to one that may be made in "showing" that
all of science and engineering boils down to Physics, or that the only
truly original discoveries appear in some esoteric branches of
Physics, and everything else follows.
   The point is not that the basic problem of CM has remained unchanged
for the past four centuries.  It is that all the variations on that
problem have prompted some remarkable contributions from a large number
of mathematicians, and more importantly, these contributions have had
implications far beyond just CM.
                                   Srinivas Bettadpur

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

End of SPACE Digest V12 #651
*******************