96072A search (was Titan 4 launch)
Ted Molczan (molczan@fox.nstn.ca)
Mon, 30 Dec 1996 10:36:03 -0500
Based on Anthony Beresford's and Rob McNaught's observations of 30 Dec,
posted earlier to SeeSat-L, it is clear that the bright object from
the 20 Dec 96 Titan launch is continuing its rapid decay. It was
approximately 2.4 min late relative to the search elset I posted yesterday:
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
I expect to issue revised elements later today. Rob McNaught's obs on
adjacent passes confirms that the object is in a 15+ rev/d orbit, and
not a 14+ rev/day, as I had speculated. I continue to be amazed at its
brightness - Rob reported mag 3 at range 2100 km, over 80 percent illuminated.
That implies a std magnitude of about 2! (A value of 3 seems to best fit
the all of the observation reports, on average.)
Although it seems too bright for a Titan 4 stage, and it is not flashing,
its orbit is very consistent with expectations for a KeyHole rocket;
therefore, I am beginning to believe that it is the rocket. (I have
entertained the possibility that the Titan 2nd stage failed to separate,
leaving a 27 m long, 3 m dia object, but I note that NORAD has catalogued
both a payload and a rocket. Then again, they are the same folks who
mistakenly catalogued LandSat 6, which failed to orbit.)
This raises the question as to the whereabouts of the payload. I have
derived the search orbit below, which is consistent with the plane of the
above orbit when precessed back to lift-off, and with the orbit of
95066A, with which it would be expected to form a constellation.
The mean motion is a guess, based on the assumption that 95066A had
manoeuvred to raise its apogee not long before 96072A was launched.
(Extrapolating its last known orbit on day 96278 suggested that it
was due for an apogee boost about the time of the 96072A launch.)
Please note that the search orbit does not have a realistic mean anomaly,
so it cannot (except by luck) produce accurate prediction times. It is
useful only for establishing the correct orientation of the orbital plane
for search purposes. So searchers will have to be prepared to stare at
the orbital plane for up to one full revolution before they spot the object.
Currently, the apogee is near 30 S latitude, so the same folks who are
tracking the supposed rocket body have an excellent opportunity to find
96072A. Be warned that near apogee the object is not particularly bright,
so binoculars are absolutely required to ensure spotting it.
USA 129 search 15.0 3.0 0.0 5.1 v
1 24680U 96072 A 96350.75277778 .00000000 00000-0 00000-0 0 00
2 24680 97.9100 50.7000 0535000 173.0000 0.0000 14.74000000 00
Clear skies!
Ted Molczan