RE: Unidentified subject!

Ted Molczan (
Wed, 1 Jan 1997 10:55:14 -0500

Anthony Beresford wrote:

>Well I missed out on a fix tonite, but its still within a
>minute or so of the predictions and the second pass tonite,
>peaking at 30 deg altitude in West( 1334UT Jan 1) it was tumbling between
>invisiblity in 7x50's and mag 3.5. Period about 35 seconds.
>So it looks like its the rocket, or the payload and the rocket
>still stuck together, and presumably because of some problem

This is the first sign of tumbling, and it seems
to have become *much* dimmer. Invisibility in
7x50s is about mag 10, so if it was peaking
at 3.5, then the mean mag was about 6.8.
If I use the normal Titan 4 2nd stage std mag of 
4.82, then I obtain about mag 6.3 for the pass
you observed, in close agreement with the
6.8 average estimated above.

I do not want to hang too much on one obs, but one
possible interpretation is that the payload was
attached, but has now separated. The slow tumble
is reminiscent of 91017B, after it deployed
Lacrosse 2. Lacrosse and KeyHole are 3-axis
stabilized, so there is no reason for their rockets
to spin. The rapidly spinning Titan 4 2nd stages
we have observed, 90050E, 91076B, 96029B and 
96038B, all deployed spin-stabilized payloads.

So perhaps we have been witnessing a late separation.
I say late, because I cannot explain why the initial
apogee of 1038 km would be allowed to decay to below
900 km, since 1038 is very near the operational value 
for a KeyHole, and 900 km is far below. So the payload
would have to consume additional propellant to raise
its apogee.

Of course, this may be too much to read in to a single
observation. I will be interested to see (through your
eyes) how this develops in coming days. Also, I hope
that someone is searching for the payload. I can provide
look angles if it will help.

Clear skies!