Kevin Fetter responded to Greg Roberts: > --- On Fri, 12/21/12, Greg Roberts <grr@telkomsa.net> wrote: > > UNKNOWN SEEN: > --------------- > 88888 12 854A 0433 G 20121220184654740 55 15 0415413+244919 19 +050 05 > 88888 12 854A 0433 G 20121220184657740 55 15 0414136+252615 19 +050 05 > > UNID > 1 99999 12355.78261273 0.00000237 00000-0 50000-4 0 02 > 2 99999 98.7779 32.6361 0007144 274.2656 61.2462 14.59474373 06 > > My dumb question of the day, could this sat in a 98 degree orbit, be a essaim sat. Been > awhile since they have been observed. It's the kind of dumb question I like. I have yet to analyze Greg's UNID, but if I cannot match it to anything else, I will consider the Essaim satellites. It is a little known fact that they were decommissioned into faster decaying orbits in late 2010. I do not have the details at hand, but some time ago, I produced this estimate for an arbitrary date and argument of perigee: Essaim 1 estimate 407 X 660 km 1 70000U 10274.00000000 .00000000 00000-0 00000-0 0 04 2 70000 98.2800 244.9744 0183000 201.0718 49.7537 15.10000000 03 It propagates to within about 10 deg of RAAN of the circular orbit you fit to Greg's observations, which is sufficiently close to be interesting - especially if better candidates (none come to mind immediately) can be excluded. Next step is to try to fit my orbit to Greg's observations. Almost any orbit can be made to fit because the time span is short, but we can reasonably start by fixing my values of inclination, eccentricity and mean motion, and allowing the others to vary. With some effort a reasonable recovery TLE may emerge. I am pressed for time at the moment, so not certain when I will have anything more to report. Soon, I hope. Ted Molczan _______________________________________________ Seesat-l mailing list http://mailman.satobs.org/mailman/listinfo/seesat-l
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