Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V08/V8_316.TXT

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Date: Sat, 6 Aug 88 01:04:06 PDT
From: Ted Anderson <[e-mail]>
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Subject: SPACE Digest V8 #316

SPACE Digest                                      Volume 8 : Issue 316

Today's Topics:
              NASA Prediction Bulletins
            Where did the BBS go?
            Celestial BBS Missing
                 Mir elements
             Satellite Tracking Software
           SDI: More Spinoffs Than Apollo?
         Re: Time skew -- does it hurt SETI?
          Re: query about 'escape velocity'
           Re: space news from June 6 AW&ST
----------------------------------------------------------------------

Date: 30 Jul 88 20:01:13 GMT
From: cs.utexas.edu!ut-emx![e-mail]  (TS Kelso)
Subject: NASA Prediction Bulletins


For those of you who are interested in satellite tracking, the most current
orbital elements from the NASA Prediction Bulletins are carried on the
Celestial RCP/M, [phone], and are updated several times weekly.  As a
service to the amateur satellite community, the most current of these elements
are uploaded weekly to rec.ham-radio.  The Celestial RCP/M may be accessed 24
hours/day at 300, 1200, or 2400 baud using 8 data bits, 1 stop bit, no parity.

Note:  There will be a temporary suspension of the posting of these elements
       while I relocate from Austin, Texas to Dayton, Ohio.  Normal postings
       should resume in a couple of weeks.

--
TS Kelso, PhD                       ARPA: [e-mail]
The Center for Space Research
The University of Texas at Austin   UUCP: {ihnp4,allegra}!ut-emx!tskelso

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

Date: 1 Aug 88 10:15:34 MST
From: [e-mail]

From Shaver's Screen
Subject: Where did the BBS go?

I no longer am getting answers to the BBS in Austin which had the NASA predicte
d element sets for satellites.  I have not received their new address.  Does an
yone have any suggestions?  Please reply to this address, I am not currently on
 the net.

"
                                          John

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

Date:    Mon, 01 Aug 88 22:06 CDT
From: Kerry Stevenson <[e-mail]>
Subject: Celestial BBS Missing

Tried today to connect to T.S. Kelso's Celestial BBS.  However, after
dialing the number, [phone], I got a recorded message announcing
that the "number you have dialed is no longer in service." I heard
a rumor some time ago that this BBS was moving to somewhere else. Does
anyone know where it has been relocated?  What is the new number?
Is there a new number? Have we lost our only dependable source of
orbital elements?  I haven't attempted a connection there for some
months now, so I'm not surpised that I got caught in the middle of
a change.

                                                Kerry

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

Date: 3 Aug 88 19:23:00 GMT
From: a.cs.uiuc.edu!m.cs.uiuc.edu![e-mail]
Subject: Mir elements


Two-line elements for Mir
1 16609U          88210.22249169 0.00023018           20000-3 0    00
2 16609  51.6145 216.4331 0004446 167.8573 192.3121 15.74728513140290

NOTE: The source I'm using right now doesn't give B*; the figure above
is a guess at the value.

Object: Mir
NORAD catalog number: 16609
Element set: 0
Epoch revolution: 14029
Epoch time: 88210.22249169 (Thu Jul 28 05:20:23 UTC)
Inclination: 51.6145 degrees
RA of node: 216.4331 degrees
Eccentricity: 0.0004446
Argument of periapsis: 167.8573 degrees
Mean anomaly: 192.3121 degrees
Mean motion: 15.74728513 revs / day
Mean motion acceleration: 0.00023018 * 2 revs / day**2
B* drag term: 2.0000e-04

Derived figures:
Semimajor axis: 6723.24 km.
Perifocal radius: 6720.25 km.
Apogee height: 348.086 km.
Perigee height: 342.108 km.
Mean longitude at the epoch: 3.7804 degrees.
Magnitudes of short-period perturbations of the second harmonic:
    Radius vector magnitude: +/-1.01 km.
    True anomaly: +/-0.0119 degrees.
    RA of node: +/-0.0260 degrees.
    Inclination: +/-0.0204 degrees.
Secular perturbations of the second harmonic:
    Argument of perigee: 3.8439 degrees/day
    RA of node: -5.1447 degrees/day
    Mean anomaly: included in published mean motion.
Long-period perturbation of the third harmonic: X=-1.642e-03, Y=-8.719e-04


Source: NASA Goddard via National Space Society Mir-Watch Hotline
                [phone] voice.

NOTE: Apogee and perigee heights are referred to a mean equatorial radius
      of 6378.145 km, and not to the local radius of the geoid.
      All derived quantities are calculated using the NORAD SGP model of
      Hilton and Kuhlman.

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

Date: Tue, 2 Aug 88 09:31:18 EDT
From: [e-mail]
Subject: Satellite Tracking Software

I found a nice program for the Mac on Compuserve or Genie (I forget
which since I look at both regularly). It has many nice features and
what follows is from the write-up:
----

MacSat Version 1.0 March 1, 1988

Copyright (C) 1988 BEK Developers, All Rights Reserved

Permission granted for noncommercial use. The program may be copied
freely, provided no money is paid. For a copy of the latest version
and manual, send $10 to:

        MacSat
        BEK Developers
        1732 74th Circle NE
        St. Petersburg, FL 33702

Documentation

MacSat is a satellite tracking program. It can store data for up to
200 satellites and 100 stations. Data for the stations and
satellites are contained in a file called 'MacSat Data'. Default
data are contained in a file called 'MacSat Defaults'. Both files
must reside in the same directory as MacSat. Some knowlege of
satellite orbits is desired to make good use of this program.

The program requires version 3.2 or latter of the System. MacSat can
run on any Macintosh computer, provided it has 128K ROMs or greater.
MacSat2 has been optomized to run on a Macintosh II, but will crash
on all others.

Features:

   Store satellite data for up to 200 satellites.

   Store station data for up to 100 stations.

   Plot satellite ground tracks on a world map (MAP).

   View current position of selected satellites on a world map in
   real-time (RTMAP).

   Display look angles for satellites that are illuminated when the
   ground site is in darkness (LOOK).

   Display look angles for satellites at all times of the day
   (TRACK).

   Display Right Ascension and Declination for objects (LOOK and
   TRACK).

   Maintains a self contained data base on available ground
   stations, satellites, and program defaults.

   Capable of flushing the data base.

   Elements in either SSPEC or SATELE formats can be loaded
   (SATDAT.ED, STNDAT.SD, SATELE.### files).

   Can write out SATDAT.ED and STNDAT.SD data and Station and
   Element listings.

   Display the latitude and longitude position of objects
   (POSITION).

   Display orbital plane crossings at a particular site (LAUNCH).

   Display equator crossings (EQUATOR).

The following dialog boxes are used in the various programs to enter
data.

Parameter Dialog - This dialog is used to enter pass information to
the various programs. Start and stop times for a pass may be entered
in either month/day/year hours:minutes or year/day of year. Other
items that may be entered, depending on the program, are step size,
minimum elevation (satellite must be above this before data will be
output), horizon elevation, maximum range (satellite must be within
this distance before data will be output), and time zone. In some
Options, the settings dialog may be selectable.

Settings Dialog - This dialog is used to configure a particular
option run. For the Map option, displaying tick marks can be enabled
and how often the tick mark occurs can be selected. The size of the
station circle and whether to beep when complete can also be
selected. For the other options, pass headers can be selected to be
output always, only when a pass is actually found, or never (a pass
header is satellite information pertaining to the current pass).
Beep when complete can also be enabled.

Station/Satellite Select Dialog - This dialog is used to select
desired stations/satellites to use in the program. Selections are
saved in 'MacSat Data'. Multiple stations may be selected in LOOK
and TRACK programs. To select more than one object, use the shift
key and mouse to select a continuous block or the command key and
mouse to select non-continuous items. In some Options, the filter
dialog may be selectable.

Filter Dialog - This dialog is used to select filter parameters for
displays in the Station/Satellite Select Dialog. The filter can be
set up to display all stations or satellites or those loaded since
(New) or before (Old) the program was started. Stations can be
filtered based on their Latitude and Longitude. Satellites can be
filtered based on their Inclination, Mean Motion, Epoch,
Eccentricity, and International Designator.

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

Date: 3 Aug 88 14:48:10 GMT
From: ihnp4!ihuxz![e-mail]  (D Woo)
Subject: SDI: More Spinoffs Than Apollo?

[There was a 330 line message here from Defense Electronics (May 88)
that I punted.  It is available to anyone who can't get a copy of the
magazine and want to read it.  Drop me a note at [e-mail].
    Ted Anderson]

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

Date: 29 Jul 88 19:56:35 GMT
From: [e-mail]  (Jordan Kare)
Subject: Re: Time skew -- does it hurt SETI?

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>
>...One would
>tentatively expect that a race would be observable for quite a while even
>after they advanced to the point where they weren't interested in talking
>to us.  Unless our current grasp of physics is grossly inadequate, the
>electromagnetic spectrum is unlikely to be replaced by anything better
>as a species advances.

Back when I was a grad student at UC Berkeley, one of the physics
professors came up with what he thought was a mechanism for
strong coupling to gravity waves -- a QM/gravity interaction.
As far as I know, he turned out to be wrong, as I have not heard
anything about the idea for some time.  However, for a few weeks
there, it looked as though one might be able to make useful
gravity wave transmitters and receivers out of macroscopic QM
wave function systems -- say,  toruses (tori?) full of superfluid
helium.  This prompted at least one comment that now we finally
understood why SETI hadn't found anything:  everybody Out There
was sending nice, clear signals -- but in gravity waves!

On a more conventional note, even folks who still use the EM spectrum
might well advance to the point where they saw no reason to waste
energy (not to mention spectrum space) by spewing power
out in all directions.  High power TV stations
are already giving way to cable systems, and many radar systems are
being replaced with passive detectors.  Lasers and fiber optics
enhance this process.  While I doubt the Earth will be completely
radio-quiet any time soon (barring catastrophe), we may already have
passed our noisiest phase.

>
>The single most plausible reason for seeing no signs of extraterrestrial
>intelligence is that a species which advances not far beyond our own
>changes so radically that it loses interest in communication, space
>exploration, etc., at least in the forms we recognize.

You mean, like the current Administration? :-)

        Jordin (Still Searching for Terrestrial Intelligence) Kare
        [e-mail]    [e-mail]

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

Date: 29 Jul 88 21:01:19 GMT
From: [e-mail]  (Robert Firth)
Subject: Re: query about 'escape velocity'

In article <[e-mail]> [e-mail] writes:
> ...  I DO understand orbital velocity, but escape
>velocity?  Why can't you leave earth at 1 mph even?  As long as you have
>thrust to just slightly overcome gravity, it seems (to me) that you ought
>to be able to leave.

Gee, we all ask basic questions from time to time; one of the things
these groups is for is to let people learn things.  So...

'escape velocity' is, roughly, how fast you'd have to throw a ball
so it would never come back.  Ignoring air resistance and all that
stuff, of course.  It is therefore the initial velocity a
"ballistic" body must have at the surface of a uniform spherical
mass if the body is to recede from the mass for ever.  The key
word is "ballistic" - as you say, you can go anywhere at any speed
with continuous thrust.

Since Newton's laws are time-symmetric, escape velocity is also
the speed with which a body would hit the Earth if it fell from
an infinite distance, again ignoring all other effects.

Note, therefore, that the projectile fired by Verne's gun had to
be travelling with at least escape velocity when it left the muzzle,
with our intrepid voyagers squashed to a pulp inside it.  A rocket,
however, need never reach escape velocity as long as it doesn't
mind burning fuel.  Our rockets actually do reach escape velocity
because it is more efficient to burn the necessary fuel close to
the earth (that way you haven't used energy to lift lots of fuel
way up into space).

Hope that helps.

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

Date: 28 Jul 88 23:45:07 GMT
From: aplcen!aplcomm!stdc.jhuapl.edu![e-mail]  (Jim Meritt)
Subject: Re: space news from June 6 AW&ST

In article <[e-mail]> [e-mail] (Phil R. Karn) writes:
}Agreed. We really need some enlightened self-interest on both sides. An
}excellent start would be the following:
}
}1. Ban the use of nuclear power sources in low earth orbit, "low" being
}defined as anything with a lifetime less than a thousand years or so.
}Deep space missions would be fine.
}
}These two provisions would have the following highly beneficial effects:
}
}1. The seemingly regular series of Soviet nuclear-powered radarsats
}re-entering the atmosphere would stop.
}2. The increasing pollution of orbital space by ASAT and SDI tests would
}stop.
}3. Taken together, the two provisions would effectively prohibit many,
}if not most, nuclear powered SDI tests.
}
}We urgently needed the Limited Test Ban Treaty in 1963, and we urgently
}need a treaty like this now.


Not to mention the radar reconnaisance satellites that are used. (rorsat,
remember?)

What space pollution?  We haven't gotten anything (significant) into orbit
in a LONG time!  That stuff is up, shoot, fall.

What nuclear powered SDI tests? I must have missed something.  The only
nuclear-powered space weapon I have heard of is a pop-up, and its use is
forbidden under existing treaties.  What are you talking about?

SOMEBODY definitely needs enlightenment around here, all right.
maybe me?


Disclaimer: Individuals have opinions, organizations have policy.
            Therefore, these opinions are mine and not any organizations!
Q.E.D.
[e-mail] 128.244.65.5  (James W. Meritt)

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

End of SPACE Digest V8 #316
*******************