Superbird-A and DemoSat Obs, 31 Mar 99

Ron Lee (
Wed, 31 Mar 1999 08:26:33 -0700

1.	Superbird-A (#20040).  Phase shift at 03:08:45 UT on 31 Mar 99.
Once again I did not notice the equally bright flashes around the phase
shift.  This is the same phenomenology I noticed in Albuquerque, NM
a week ago.   Not sure if this signals a change in the orientation or
is just a problem with observing with a full moon nearby or in city
lights .  Phase shift time is plus/minus 1/2 period since I had to use
the leading and trailing faint/bright patterns to get the mid point.

2.	DemoSat (#25661).  First attempt was near Rigel at a range of about
26300 km.  Using a wide field setup in the 8" telescope...I missed it and
the Zenit rocket (#25662).

I tried again about an hour later east of Sirius using a "normal" field
of view eyepiece setup and saw both the DemoSat and the Zenit rocket.
according to the elsets below, the Zenit rocket was first.  It was about
20 seconds early and 5-10 arcminutes south of expected trajectory.  Magnitude
about 9.5 and steady (range 13700 km and Skymap phase angle of 101).

The DemoSat was up to 0.5 magnitude fainter and may have been fluctuating.
It was at the limit of visibility under full moon conditions so exact
details are vague.  It was also about 20 seconds early and south of expected

I had expected the rocket to fluctuate and not DemoSat.  Perhaps someone
can observe these objects closer to perigee to get better data.

SeaLaunch DemoSat                                36069 x 638 km
1 25661U 99014A   99089.10333103 -.00000205  00000-0  00000-0 0    92
2 25661   1.2170  52.7609 7162753 182.1534 171.9628  2.23237474    49
DemoSat Zenit r                                  35991 x 583 km
1 25662U 99014B   99087.76439411 -.00000182  00000-0  10000-3 0    78
2 25662   1.1968  53.2473 7177703 180.9634 178.0754  2.24140754    17

Ron Lee
Falcon, CO USA