Subject: Titan IV object observed (Was: Pre-solstice spysat launches): long
From: thomsona@netcom.com (Allen Thomson)
Date: 1996/12/30
Message-Id: <thomsonaE38DDn.GLI@netcom.com>
Newsgroups: sci.space.tech,sci.space.policy,sci.astro.amateur,alt.politics.org.cia
When I posted the query on pre-solstice spysat launches, I noted that
> I certainly don't know of any case in which a polar Vandenberg
> launch near the northern winter solstice has been spotted by other
> than a northern hemisphere observer the following Spring.
Well, I spoke a few hours too soon. According to subsequent traffic
on the SeeSat-L mailing list, an object that appears to be associated
with the 20 December 1996 Titan-IV launch out of Vandenberg has been
observed several times by an observer in Adelaide. The redoubtable
Ted Molczan has worked out some preliminary orbital elements for it,
and has given me permission to post the information here in the hopes
of encouraging other Southern Hemisphere (or daylight-capable Northern
Hemisphere) observers to report sightings. Please try to get right
ascension, declination, and time as precisely as possible. Reports
like "crossed the line connecting Beta and Gamma Librae an estimated
3/4 of the way toward Gamma at hhmmss.s dd mm yy UT" are useful also.
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BEGIN MOLCZAN MESSAGE
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From: Ted Molczan <molczan@fox.nstn.ca >
To: "'SeeSat-L'" <SeeSat-L@cds.plasma.mpe-garching.mpg.de >
Subject: Object observed from recent Titan 4 launch
Date: Mon, 30 Dec 1996 02:07:07 -0500
Over the past few days, Anthony Beresford has provided me with several
observation reports of an object that I believe originated with the
Titan 4 launched from VAFB on 20 Dec 1996 at 18:04 UTC.
The object is precisely in the standard KeyHole western orbital plane,
but its orbital dimensions are not standard, and it appears to be much
brighter than a KeyHole (approx std mag = 3, 1000 km range, 50 percent
illuminated).
The orbit is visible in the S. hemisphere at latitudes south of about 35
S. One purpose of this message is to encourage other S. hemisphere
observers to obtain accurate positional measurements and estimates. (See
search orbit at end of this message.)
Another purpose is to provide other analysts besides myself an
opportunity to contribute to understanding this object, especially its
orbit. This analysis could benefit greatly from an understanding of
high-drag orbits. I begin with a summary of Anthony's observations,
NASA's NORAD catalogue information, and conclude with my own analysis,
preliminary orbital elements, and comments.
Observations by Anthony Beresford
---------------------------------
Anthony did attempt to post his initial report to SeeSat-L, but for some
reason it did not appear. Since then, we have corresponded directly, and
have copied several other Southern Hemisphere observers. For the benefit
of analysts on SeeSat-L, here the relevant excerpts from Anthony's
sighting reports.
24 Dec 1996
-----------
>On the evening of Dec 24 (local time) I observed a high object
>coming up from the South and bisecting the line between Archenar and
Canopus.
>Overhead at 1254 UT ( + or - 1 minute). Disappeared into shadow at
>50 degrees elevation in the North. Calculations reveal shadow height
overhead
>was 710Km. Brightness steady at mag 2.5-3 .
>The time on Dec 24 came from reading my wristwatch, when
>I came back into ligt Ted. Its 17 seconds slow on UTC at momemnt
>and only varies by about a 1.5 seconds a month. I read the watch
>when it said 23:26:30 [=12:56:30 UTC] or so, and worked backwards, so
>timimg errors cant be late. I was wondering the identification myself.
>Last night I stayed outside till 13:00 just to see if something else turned
26 Dec 1996
-----------
>Tonite saw similar object in similar path. Timed at RA 4 h 25min, dec
-58.5,
>at 12h 56m 17s UT .Sowhat objects in polar orbit or higher inclination
>do we know with nodal periods very close to 13.5 or 14.5 revs /day.
>Could it be the Titan-4 launch of a few days ago.
> Observer situated at 34.96S, 138.66 E ( cospar 8597)
27 Dec 1996
-----------
>Saw it again tonite Ted had binoculars, but
>I didnt press stopwatch hard enough to start it.
>So apart from saying it was 1251 UT overhead,
>I cant say much more. It was 7 minutes earlier than
>predictions based on the elements you sent me.
>If anything its maximum brightness tonite was
>mag 2.0, an easy naked eye object.
28 Dec 1996
-----------
>object tracked reached mag 2.5 high (70 deg in Eastern sky)
>Postion near Canopus timed at 12h 46 min 13.8 sec UTC
> RA 6h 10.0 min )
> Dec -55deg 05 min ) Epoch 2000
>After getting time. I continued watching orbit
>pane till 1302UTC and saw nothing more.
29 Dec 1996
-----------
>I saw the usual bright ( mag 2.5)
>object at 1238UT RA 7h 08.0 min, dec -49.2 degs. The postion is
>accurate but the time is only + or - 20secs.
>After getting back out at 1248 I watched till 1311 UT. Only other
>object I saw was Lacrosse 2 heading S.
NORAD Catalogue
---------------
NORAD has catalogued two objects from the 20 Dec launch, as would be
expected. Presumably, the second object is the Titan 2nd stage.
Also, I note that there is an 18 object gap immediately after the second
Titan-launch object. Most likely, this will turn to be debris from an
unrelated launch. If it turns out to be from this launch, then that
would be significant. I am not aware of any debris having been
catalogued from a KeyHole sun-synchronous launch.
1996 072A USA 129 24680 US 20 DEC ELEMENTS NOT AVAILABLE
1996 072B 24681 US 20 DEC ELEMENTS NOT AVAILABLE
OBJECTS 24682 THROUGH 24699 HAVE NOT BEEN CATALOGED BY USSPACECOM.
1995 062C 24700 ESA 17 NOV ELEMENTS NOT AVAILABLE
1996 073A BION 11 24701 CIS 24 DEC 90.4 62.8 378 217
1996 073B 24702 CIS 24 DEC ELEMENTS NOT AVAILABLE
My Analysis
-----------
Using the observations of 24, 26 and 27 Dec, I derived my first preliminary
orbit:
99999A 15.0 3.0 0.0 3.0 v
1 99999U 99999 A 96361.53908565 .02800000 00000-0 95384-3 0 01
2 99999 97.9100 61.6000 0575000 152.0000 168.4000 15.05000000 01
This is a pretty good fit to the data. The times of the observed events
are reproduced to the observed precision, typically one minute. On the
24th, the shadow entry occurs at about 50 deg elevation, as observed,
but the azimuth is about 10 deg east of the observation. Also, the
bisection of Canopus-Archenar is not exact, also somewhat east of the
observation. Anthony advises that those angles were not very precise.
The above elset is extremely close to the standard western KeyHole
plane, moreover, none of the known sun-synchronous objects near this
plane coincided with the observations. The shadow entry helped to
determine the eccentricity and the argument of perigee, because its
elevation was very sensitive to those variables. Precessing the argument
of perigee 5.8 day back to the time of launch yields about 173 deg, in
close agreement with past launches. A launch from VAFB, with insertion
into an elliptical parking orbit produces an argument of perigee between
about 160 and 175 deg, depending on the mission.
I am not aware of any previous observations of KeyHole objects so soon
after launch, so I do not know the typical evolution of the orbits. From
U.S. reports to the U.N.; and Tass/Itar, I do have the following
dimensions of the Titan 2nd stage orbits, presumably very soon after
launch:
Object Inc Per Apo Period Source
--------------------------------------
87090B 97.8 143 1018 96.3 U.S.
88099B 97.9 154 1008 96.3 U.S.
92083B 97.7 156 911 96.4 U.S.
95066? 98.7 156 976 95.7 TASS
Heights are in km, and period is in minutes.
The perigee of 92083B, is my revision. The U.N. report stated 256 km,
but this was almost certainly a typo. My value closely fits with the
orbital period. (The U.S. submissions to the U.N. have been found to
have numerous errors of this sort.) Regarding 95066, the article implied
the payload, but the orbit could have been either the Titan 2nd stage
or the payload. Also, the period is too low , and the inclination was
too high.
So generally, the KeyHoles have entered parking orbits of about 156 x
1000 km, at nearly 97.9 deg inclination. All that was required to attain
the standard orbit, was to raise the perigee to about 270 km altitude.
My first preliminary orbit had dimensions of about 160 x 957 km, which
agrees closely with these orbits; however, that was 5.8 days after
launch. Taking into account the ndot/2 decay term of 0.028 rev/day^2,
the initial orbit would have been about 160 x 1160 km. The apogee is
quite a bit higher than that of a standard KeyHole, which I find
strange. Why would they launch into such a high apogee, and then allow
drag to eat up nearly 200 km of it?
The observations of the 28th and 29th added their own problems. The
first preliminary orbit does not fit them well, mainly because it
predicts much earlier passes than were observed. My second preliminary
orbit has epoch on 28 Dec:
99989A 15.0 3.0 0.0 3.0 v
1 99989U 99989 A 96363.53210417 .02300000 00000-0 57503-3 0 09
2 99989 97.9100 63.6600 0570000 145.0000 176.4000 15.07500000 01
This fits the 27, 28 and 29th well, but there are some puzzling aspects:
- the mean ndot/2 since the first preliminary elset is 0.00625 rev/day^2,
yet actual decay rate has only decreased from 0.028 to 0.023 rev/day^2.
This suggests a small manoeuvre took place on or after the 26th.
- by the time of the obs on the 29th, the mean motion would have been about
15.121 rev/d, implying an orbit of 160 x 913 km. That is a great deal of
decay since the initial parking orbit, and much lower apogee than a
standard
Kh orbit.
One argument is that this is really the rocket body, but in that case,
why did it apparently manoeuvre between the 26th and 28th? Also, why is
so much brighter than a Titan 2nd stage is known to be? The standard
magnitude of previous stages was about 4.8; this object's is around 3.
Also, why is it not flashing? All past Titan 2 stages observed by
hobbyists (90050B, 91017B, 91076B, 96029B and 96038B) flashed, all
except 91017B had initial periods between 1 and 6 seconds; 91017B's was
between 10 and 20 s.
If this is the payload, then why has it been allowed to decay so much
since launch 9 days earlier? Also, why is so bright? Kh's 92083A and
95066A are not normally magnitude 2 to 2.5 near apogee, even under the
best circumstances. There std mag is about 5; this object's seems to be
about 3. Perhaps its orientation is unusual.
Finally, I have considered the possibility that the orbit is closer to
14.07 rev/day than 15.07 rev day. In that case, I would expect to be
nearly circular. The following elset roughly fits the obs of 26-29th,
but not well enough to argue that it is correct:
99991A 15.0 3.0 0.0 3.0 v
1 99991U 99991 A 96361.53908565 .00000000 00000-0 00000-0 0 03
2 99991 98.9093 60.8000 0000000 0.0000 321.7000 14.06700000 02
Southern hemisphere observers are advised to use the following orbit
for searching:
99989A 15.0 3.0 0.0 3.0 v
1 99989U 99989 A 96363.53210417 .02300000 00000-0 57503-3 0 09
2 99989 97.9100 63.6600 0570000 145.0000 176.4000 15.07500000 01
Allow at *least* a 10 minute uncertainty.
Be prepared for anything. If the object suddenly manoeuvres to its
standard orbit of 270 x 1000 km, then it will arrive about 23 min later
each day. Also, be on the lookout for a second object near this object's
orbit. Ideally, should consist of precise timings of precise positional
sky coordinates. Please include time and location of shadow entry. Also,
please note colour and magnitude and flash period.
Post your observations to SeeSat-L, or e-mail them directly to me.
Clear skies!
Ted Molczan
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