Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V11_5/V11_559.TXT

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Subject: SPACE Digest V11 #559

SPACE Digest                                     Volume 11 : Issue 559

Today's Topics:
               Satellite Images on Mac
  Re: US/Soviet Planetary Activity (was Re: Manned mission to Venus)
         Re: Aim For The Moon - model rocket contest
     Re: Space incentives (was Re: NASA 91 Appropriation (long))
           Hubble Space Telescope Update - 06/21/90
       Re: NASA Headline News for 06/21/90 (Forwarded)
         Re: Hubble Space Telescope Update - 06/21/90
          redefining time units (was Re: SpaceList)

Administrivia:

    Submissions to the SPACE Digest/sci.space should be mailed to
  [e-mail].  Other mail, esp. [un]subscription notices,
  should be sent to [e-mail], or, if urgent, to
             [e-mail]

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

Date: 23 Jun 90 00:50:55 GMT
From: ux1.cso.uiuc.edu!pequod.cso.uiuc.edu![e-mail]  (Andrew Higgins)
Subject: Satellite Images on Mac

In <[e-mail]>, [e-mail] (James R. White) writes:

> Does anybody know of any software that will display a series of GIF
> files in rapid succession that runs on the MAC?  It would be useful
> for animating the weather satellite photos.

Well, here's one way to do it.  It's rather a long process, so you may
want to print this out first.

    Viewing and Animating Satellite Images on a Macintosh
    -----------------------------------------------------

1)  Getting the Images.

As has already been pointed out in this group, you can obtain images (in
GIF format) from the NOAA birds via an anonymous FTP to VMD.CSO.UIUC.EDU
in the directory phil.515.  The pictures are updated frequently and can
be available as little as a few hours after they are taken.

The satellite images have names in two different formats.  One name
format resembles:

    EImmddhh.GIF

    E or W depending on view from East or West
    I or V depending on Infrared or Visual spectrum
    mm for month
    dd for date
    hh for hour

The other name format looks like:

    Nyyymmdd.GIF

    N (unknown)
    yyy 3 digits of year
    mm month
    dd date

I'm not at all sure what time system they use to name these files, but
it could well be UTC.

Transfer the GIF files to your Macintosh, being careful to maintain a
binary file type.

2)  Converting the Images to HDF

Unfortunately, I know of no way to directly display GIF images on a
Macintosh.  However, GIF files can be converted to HDF raster images.
Once in HDF form, they can be viewed and even animated on a Macintosh.
HDF, or Hierarchical Data Format, if a flexible file format developed by
the National Center for Supercomputing Applications (NCSA) at the
University of Illinois Urbana/Champaign.  HDF is designed to be a new
standard for sharing graphical and floating-point data among different
users and machines.  An HDF image set contains a raster image, its
dimensions, and a palette.

To convert your GIF file to an HDF file, you will need a Macintosh
program called Import2HDF developed by NCSA.  This program and its
documentation are in the public domain, and can be obtained via
anonymous FTP to ftp.ncsa.uiuc.edu.  You will need Binhex and StuffIt to
create the application on the Macintosh.  Documentation for Import2HDF
in form of Microsoft Word 4.0 files is also available at the same
address.  To use NCSA Import2HDF you need a Macintosh with 256 color or
gray-scale capabilities, at least one megabyte of RAM, and a monitor.

3)  Viewing and Animating the Images

Once you have the satellite images in HDF format, their are a number of
NCSA programs you can use to display and manipulate them on the
Macintosh.  I would recommend using NCSA Image (also in the public
domain and available via anonymous FTP to ftp.ncsa.uiuc.edu).  This
program is part of NCSA's Scientific Visualization Suite.  NCSA Image
also requires a Macintosh with 256 color capabilities, at least one
megabyte of RAM, and a color monitor.  It can be run on a non-color
equipped Macintosh, but many of its functions will be rendered useless.
NCSA Image will allow you to view an HDF file or animate a sequence of
HDF files.  Again, documentation is also available for Image in the form
of Microsoft Word 4.0 files.  To print an image, you will need to use
another NCSA program called Layout, available at the same FTP site.

Good luck!

NOTE:  I am not an employee or representative of the National Center for
Supercomputing Applications.  I take no responsibility for the NCSA
software mentioned in this posting.  Please send all questions or
suggestions regarding NCSA software to [e-mail] (INTERnet)
of [e-mail] (BITnet).
--
    Andrew J. Higgins
    Aerothermal Simulations Laboratory
    Department of Aeronautical and Astronautical Engineering
    University of Illinois Urbana/Champaign

    INTERnet:    [e-mail]
    HEPnet:        UIASLA::HIGGINS

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

Date: 22 Jun 90 23:27:00 GMT
From: usc!samsung!crackers!cpoint!frog![e-mail]  (John Woods)
Subject: Re: US/Soviet Planetary Activity (was Re: Manned mission to Venus)

In article <[e-mail]>, [e-mail] (Mark SOKOLOWSKI) writes:
> In article <[e-mail]> [e-mail] (David Lewis) writes:
> >I've been watching this discussion, and I find the attitude that 'the
> >only worthwhile things to do are those which haven't been done' rather
> >distressing.
> We would still be in the trees if we would restrict ourselves to things
> that were done and are done on a regular basis.

Fine.  When there are daily flights to the Moon, I'll be willing to
call it uninteresting.
--
John Woods, Charles River Data Systems, Framingham MA, [phone]
...!decvax!frog!john, [e-mail], ...!mit-eddie!jfw, [e-mail]

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

Date: 20 Jun 90 23:11:37 GMT
From: swrinde!zaphod.mps.ohio-state.edu!mips!prls!philabs!ttidca![e-mail]  (Trigger)
Subject: Re: Aim For The Moon - model rocket contest

In article <[e-mail]> [e-mail] (Patrick John Horgan) writes:
+>WOW!  What an idea:)  Is this really feasible?  I would have thought
+>that the normal construction methods for model rockets would result in
+>the destruction of the model by the thrust of the early stages.  Does
+>anyone know the altitude record for model rockets using "normal", i.e.
+> D size engines?=>
+>Patrick Horgan                         [e-mail]

Ahh, If you were to try to use 'D' motors to achive orbit, the vehicle
would have to be 1/2 times bigger on each stage, rendering the damn
thing too heavy... Just think of the clustering problems.   (^%
Forget 'D' and think 'I' or 'J'. I believe that U.S. Rockets has the
best price in town, even though Aerotech has the WhiteLightning, U.S.
Rockets is at least $2.00 cheaper on the 'F' and 'G' motors I use.
(btw: U.S. Rockets has there own type of 'special effect motors'.)

Also, Aerotech does not make booster stages anymore and U.S. does...

Did any of you make it out ot the summer launch at Lucern Dry Lake?

I took a new FSI Black Brant, stuck a Aerotech G40-13 in it... What
a show....

If any of you are thinking of buying FSI products I'll let you know now
that there motor mounts are too small for any type motors but FSI's..

When I tried sticking the Aerotech motor in it was way too small, and I
ended up sanding the motor mount down to size. The only problem was
when I tried taking out the motor the damn motor tube broke inside
the body tube about 4" up from the boat tail. (sigh..)

later on,

trigger


_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_
* Trigger (aka: Ron Soto)                                                   *
* Citicorp / TTI                                                            *
* Santa Monica, Ca. 90405    [phone], ext. 2208                      *
* Path: {retix|philabs|csun|psivax}!ttidca!soto   or   [e-mail]  *

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

Date: 21 Jun 90 15:21:46 GMT
From: usc!cs.utexas.edu!helios!tamuts![e-mail]  (Lee Cox)
Subject: Re: Space incentives (was Re: NASA 91 Appropriation (long))

In article <[e-mail]> [e-mail] (David Smith) writes:
>
>All this talk about prizes is (for the sake of this argument) nonsense.
>What we really should do is hire a launch of a light sail.  Sail it out
>to an asteroid, link up with it, and sail the asteroid over into an orbit
>which will cause it to collide with Washington, Moscow, Paris, Tokyo,
>or Canberra.  Disconnect sail.  Point out fact to world.  That ought to get
>some kind of action on some sort of space development.
>
>      :-)   <-- Is the smiley really necessary?
>

Point it at New Zealand and tell them the only thing that will stop it
is a thermonuke.

************************************************************************
 Lee Cox                          BITnet: H1C5962@TAMSTAR
                                  HEPnet: FNBIT::TAMHEP::THOR::H1C5962
 Asst. Systems Manager          Internet: [e-mail]
 Academic Computing Services        SPAN: UTSPAN::UTADNX::THOR::H1C5962
 Texas A&M University             THEnet: THOR::H1C5962
 College Station, TX 77843-3154   GTEnet: [phone]
                     Paranoia is our profession.
************************************************************************

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

Date: 22 Jun 90 16:50:08 GMT
From: usc!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Hubble Space Telescope Update - 06/21/90


                            Hubble Space Telescope Update
                                  June 21, 1990

     Most of the activity for the past 24 hours has been directed toward the
state of the focusing the Hubble Space Telescope (HST).  It does appear that
problems are being sorted out and plans of attack being formulated.  It is
apparent that one of the major obstacles to getting HST focused is the low
quality and quantity of the enlisting data.  As such, the major line of attack
is to modify the data gathering procedures to improve the data quality and then
gather more data.  So the next few days have a fair amount of wavefront sensor
measurements and Wide Field Planetary Camera (WFPC) pictures to better
define the degree of focus of HST.  Guide star fine lock was not going well
(failed acquisitions and frequent drop outs from fine lock) so real time
commands were issued to reinsert the 2/3 aperture.  Fine lock acquisitions did
improve but there were still some problems.   A new type of loss of fine lock
in the Fine Guidance Sensor (FGS) occurred: loss of lock induced by the South
Atlantic Anomaly (SAA) (not "bit flips") -- the failure is under study.  All
is quiet with the other spacecraft subsystems, including the Scientific
Instruments (SI).

     One fine lock dropout was found to occur as a result of passage through
the SAA.  This is the first time that SAA passage caused a loss of lock.  The
problem is under investigation.  WFPC found that one of their images was
obtained in the middle of a terminator disturbance and show double images plus
evidence of rapid jitter.  The image was passed on to Lockheed Pointing Control
Subsystem (PCS) people for analysis.

     The HST focus was again the major topic of discussion in the past
24 hours.  There now seems to be general agreement that the data on hand is far
from ideal, being ambiguous and contradictory in many cases.  In essence,
reanalysis of the old data appears to have diminished confidence in the derived
conclusions.  Thus, the major effort of the next few days will to take more
data, taking specific care to improve the data quality.  A few additional tests
are also being run.  The secondary mirror was moved to a position significantly
out of focus (~10 waves toward the primary), a series of WFPC pictures are now
being taken with the mirror in this position.  Later, the secondary will be
moved again, to a point ~5 waves from focus (toward the primary) and more WFPC
images will be taken.

   The secondary will then be moved back to the position it was in yesterday.
On June 22 a new focus run will begin, Bootstrap Phase B part 5c, with more
wavefront sensor (WFS) measurements.  Focus runs (WFS measurements, possible
mirror movements, and WFPC images) will be executed through the weekend and
into the beginning of next week.  The expectation is that much of next week
will also be filled with more focus runs.  A lot of new data will be coming
in over the next few days, the results from the "way out of focus" images
should be interesting as should the new WFS measurements.  One point of
discussion regards what focus star to use: iota Car can only be used for a
short time more (~5 to 10 days) before it becomes too close to the sun.
Switching to another star requires a major effort to select the star, and
a repeat of earlier Bootstrap SMS in order to get the alignments needed to
successfully use the WFS measurements. Iota Car will continue to be used
at the present time.

     Nothing new on the analysis of the 10 Faint Object Camera (FOC) images.
A press release is expected shortly.

     The Astrometry Team (AST) is the most active team with the focus tests
running.  They are supporting Fixed Head Star Tracker (FHST) calibration
planning, assisting in finding a new focus star, and checking out fields for
the FGS's.
       _   _____    _
      | | |  __ \  | |       Ron Baalke           |  [e-mail]
      | | | |__) | | |       Jet Propulsion Lab   |  [e-mail]
   ___| | |  ___/  | |___    M/S 301-355          |
  |_____/ |_|      |_____|   Pasadena, CA 91109   |

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

Date: 22 Jun 90 16:06:48 GMT
From: uvaarpa!murdoch!astsun9.astro.Virginia.EDU![e-mail]  (Philip C. Plait)
Subject: Re: NASA Headline News for 06/21/90 (Forwarded)

In article <[e-mail]> [e-mail] (Peter E. Yee) writes:

>President Bush visited Marshall Space Flight Center yesterday.
....

>confirmed his commitment to the Space Exploration Initiative. He
>said the Initiative is a 3-fold program that includes the
>completion of Space Station Freedom, the mission to the moon and
>that an American flag should be planted on Mars in 30 years.

I guess this means we'll never go to Mercury.

The flag might catch on fire!


--
* Phil Plait                  [e-mail]
* UVa Dept. of Astronomy      Grad student (at large)
*
* "Censorship? You're worried about censorship when you write crap like that?"

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

Date: 22 Jun 90 18:57:47 GMT
From: [e-mail]  (John Misner)
Subject: Re: Hubble Space Telescope Update - 06/21/90

In article <[e-mail]> [e-mail] (Ron Baalke) writes:
>
>                            Hubble Space Telescope Update
>                                  June 21, 1990
>
>...                                           A new type of loss of fine lock
>in the Fine Guidance Sensor (FGS) occurred: loss of lock induced by the South
>Atlantic Anomaly (SAA) (not "bit flips") -- the failure is under study. ...
>
>     One fine lock dropout was found to occur as a result of passage through
>the SAA.  This is the first time that SAA passage caused a loss of lock. ...
>
As the original orbit avoided the South Atlantic Anomaly in the first few
orbits by means of the night launch, I presume that precession of the orbit
brings the HST through the SAA for every orbit for a range and then misses
the SAA for every orbit in a range.

What are the counts of these two ranges?  Assuming, for instance, that the
ratio of (in SAA) to (not in SAA) is, say, 1 to 9, does this mean that
availability may be reduced to a maximum of 90% of the time even if the
terminator problem is solved?

A secondary question which I could drag out of elementary texts, I'm sure,
is:  is the precession Eastward or Westward?

jm ([e-mail])

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

Date: 23 Jun 90 00:13:29 GMT
From: unmvax!nmt.edu![e-mail]  (Daniel Briggs)
Subject: redefining time units (was Re: SpaceList)

In article <[e-mail]> [e-mail] writes:
>
>I agree as a scientist that redefining the second so that there are 10**5 each
>day would make certain calculations easier, but the general public would never
>go along with such an idea (too confusing!).

I must admit that I come down on the other side of this issue, (even
hypothetically), which kind of surprises me.  By and large, I think
that the only people who would really be "helped" by this sort of
redefinition would be people who have to deal with both time and
astronomy, (although that includes the practical aspects of astronomy
as well as the pure researcher.)  The fact is that for many of these
sort of people a simple multiplicative scale factor is the least of
our worries when dealing with questions of timekeeping.  Just what
kind of second are we going to be redefining?  The IAT second,
perhaps?  If so, how does that relate to UT, UTC, UT1?  Or, God help
us, the more obscure variants of UT2 & UT3?  I haven't even touched
siderial time, and I could probably dig up a few more variants of UT
if I tried.  All of these are *almost* the same, with various
corrections added or not added, or truncated to an integral offset
with respect to another or not.  The subject of timekeeping,
especially when connected the motion of the earth through space, is a
complicated one.  At best, redefining "the" second will only clean up
one or two of these scales.  All the rest will be just as ugly as they
ever were, and now you have the added confusion introduced by the
redinition in the first place.  The redefinition just doesn't buy you
enough.

--
This is a shared guest account, please send replies to
[e-mail] (Internet)
Dan Briggs / NRAO / P.O. Box O / Socorro, NM / 87801  (U.S. Snail)

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

End of SPACE Digest V11 #559
*******************