Probable Titan 4 objects observed - looks like SDS

Ted Molczan (
Wed, 3 Jul 1996 23:19:13 -0400

I have just received a report from an Ohio observer, who wishes to
remain anonymous, that he observed two objects that are consistent 
with the following search elements:

99610A          15.0  4.0  0.0  4.2
1 99610U 99610  A 96185.02152778  .00000000  00000-0  00000-0 0    04
2 99610  57.0000 187.9400 0000001   0.0000  18.9000 15.00000000    03
99710A          15.0  4.0  0.0  4.2
1 99710U 99710  A 96185.02152778  .00000000  00000-0  00000-0 0    06
2 99710  61.0000 190.9700 0000001   0.0000  17.5000 15.00000000    01

He was following an observation program that I devised for him.
He was observing in twilight, so it was difficult to see reference
stars. Judging by his report, the path was closer to the 57 deg orbit;
however, I recommend producing ephemerides for the 61 deg orbit as well.

Obviously, at this point we do not know the eccentricity of the orbit,
which also affects any judgment of the inclination. Also, the Titan
may have executed a dog-leg during the ascent, which would affect the
observed path.

He observed from 41 N, 81 W. The first object appeared at 02:18 UTC
on 4 July, on a low pass in the NNW. He judged the maximum elevation
at greater than 20 deg, which favours the 57 deg orbit. The object
was about magnitude 1, flashing with a period of about 10 seconds.

The second object followed about 1 minute later, on the same path.
It produced rapid, specular flashes, with a period no greater than
1 second. He also noted a very slight reddish tinge.

Both objects were observed for about one minute, and their direction
of travel was consistent with the elements.

I believe that the first object was most likely the Titan 2nd stage;
the second was the payload. The description of the payload is very
reminiscent of both 89061B and 92086B, the first two SDS 2 payloads,
deployed from the space shuttle.

The Ohio observer has two more passes before dawn, and he will report
his findings to me after each pass. The final pass will be at high
elevation, which should help to determine the inclination. The observer
is not well equipped to do accurate positional obs, but if he can spot
the objects on the next two passes, that will help greatly to nail down
the orbit.

For now, I recommend using the above elements, with a generous allowance
for prediction error, say 10 minutes.

bye for now