Re: Lacrosse 1 and APR2-3.OBS

Bjoern Gimle (b_gimle@algonet.se)
Fri, 11 Apr 1997 23:41:03 +0200

Russell Eberst wrote:
...
>9900000 043608.02 003359+574616 6.6 6.6 0 S
>...
>Note: the unknown at 04:36 is believed to have approx elements:
>inclination 62 degrees,: RAAN 171 Degrees,: revs/day if circular 14.0
...

Hello Russell,

A little late, but I finally checked your observation (by the same
simple method - edited in an elset to match the text above, plotted
all objects predicted brighter than +9 and within +/- 7 minutes and
a range of 5000 km from file el970329.
"Your" orbit is within about 2 degrees from the position, but the
only object closer is 8102102 at 04:30, but its Epoch is 97086 and
shouldn't be inaccurate. Its inclination is 64.96, RAAN 201.7, and
the direction of motion is more than noticably different.
(MM is 13.86, which should be acceptable)
81021  A
1 12319U 81021  A 97086.76063348 -.00000123  00000-0 -28889-4 0    72
2 12319  64.9573 215.8165 0042392 153.5772 206.7468 13.86180246815309

Regarding the possible observation of Lacrosse 1 by Robert Sheaffer
on 970411 at 03:56 - it must have done at least one revolution (less?)
then predicted since your obs on 970324. I can't find your mail at the
moment, sitting on a train back to Stockholm, but I looked +/-5 min.
on or a few days after 970327 - as I imagine lots of observers did.
When did you miss it, and when, and how long, have you searched ?

If it were only 10 minutes late in less than 17 days, *everybody* would
have seen it. It could be 108 or 206 minutes late ( or 88 minutes early ) ?

Here are some possible search orbits, assuming a small orbit change
on Mar.25 :
88106  B  97084.344  
1 19671U 88106  B 97084.34433668  .00000035  00000-0  56900-5 0    19
2 19671  56.9770  58.4364 0010000 149.9997 210.1598 14.70734765  2494
88106  B  -0.06 MM  
1 19671U 88106  B 97084.34433668  .00000035  00000-0  56900-5 0    19
2 19671  56.9770  58.4364 0010000 149.9997 210.1598 14.64234765  2494
88106  B  -0.12 MM  
1 19671U 88106  B 97084.34433668  .00000035  00000-0  56900-5 0    19
2 19671  56.9770  58.4364 0010000 149.9997 210.1598 14.58234765  2494
88106  B  +0.05 MM  
1 19671U 88106  B 97084.34433668  .00000035  00000-0  56900-5 0    19
2 19671  56.9770  58.4364 0010000 149.9997 210.1598 14.76134765  2494
88106  B  -0.01 MM  
1 19671U 88106  B 97084.34433668  .00000035  00000-0  56900-5 0    19
2 19671  56.9770  58.4364 0010000 149.9997 210.1598 14.70134765  2494



I have a hard time searching, predicted elevation tonight 10 degrees.




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