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DRA project revived: 95- 32 B

Bart De Pontieu

I would like to ask that all flash period observers mark 95- 32 B (23604, Cosmos 2315 r) as absolute top-priority. I am now restarting the DRA project (Determination of Rotation Axis) with 95- 32 B currently as the only satellite that we track. In a few weeks time I may consider adding some other satellites. Note though that you should still send in your DRA obs of any other object you happen to see/record. It's just that 95- 32 B should get highest priority as far as DRA obs go.

Using the DRA observations of Walter Nissen and Leo Barhorst during April, I was able to relatively accurately determine the direction of its rotation axis on 4 days. I would like to follow up on this object so that we can track the motion of the rotation axis as a function of time.

What happened in April, I think, is that Walter had the good fortune to observe 95- 32 B at a time that its rotation axis was pointing at a direction which roughly coincided with the direction of the bisectrix between the vectors satellite-sun and satellite-observers. This allows the observer to see a synodic anomaly. Some time later the rotation axis had moved through that region and the synodic anomalies disappeared. The subsequent observations did not show any synodic anomalies, but a clear synodic effect, allowing relatively precise determination of the rotation axis.

I will in the near future try to develop a model that integrates the temporal evolution of the direction of the rotation axis using theoretically derived values for the external torques acting on the rocket body. This could lead to a decision on which solution describes the real rotation axis.

What I need for my DRA analysis is: Date of obs, location of observer (latitude and longitude), start time of the obs, and all times of the flashes measured with respect to the start time. The times should be given with an accuracy of 0.1 seconds.

Preferred are *long* series of timings. The best would be to track the satellite from horizon to horizon. If you have a chance to observe the satellite several times on successive days, try to observe passes that do not have the same illumination conditions. E.g. don't always observe low northbound passes, or only zenital passes. Try to vary as much as you can, this greatly improves the accuracy of the determination of the rotation axis.

95- 32 B is currently visible from moderate northern latitudes. This visibility period lasts until the end of July for observers at +50 degrees latitude. It would be great if we could collect a great number of observations until then.

Recent orbital elements of this object:

1 23604U 95032B   96143.00648170 +.00000015 +00000-0 +00000-0 0 01302
2 23604 082.9056 118.8059 0028463 089.4150 271.0268 13.73607833044183

next up previous
Next: Jonathan's Space Report Up: No Title Previous: Results

Bart de Pontieu
Fri May 24 11:30:41 MET DST 1996