ALERT: Iridium 48 ambiguity

Walter Nissen (dk058@cleveland.Freenet.Edu)
Tue, 13 Apr 1999 06:31:08 -0400 (EDT)

Like Mike McCants, I lean toward an explanation that likely SPACECOM is 
now releasing elsets for a different, or new, object, but using the 
catalog number and COSPAR id of an operational object.  As pointed out 
last year in my "WARNING" message, this is a very difficult type of 
confusion to handle. 
 
People will have to purge their files of elsets like those shown below as 
"New, from OIG", or run special, separate predictions, if they want to 
have a chance to view the original object (assuming she is still on 
course) shown below as "Last good elset". 
 
Conversely, it seems that Alan Pickup's decay predictions may soon be 
needed for "New, from OIG". 
 
Observations are badly needed to help resolve the ambiguity.  "Last good 
elset" didn't show up in "deep search" predictions for my location 
tonight.  Perhaps in the Southern Hemisphere?  Or far North?  A careful 
observation of a bright glint of a normal character from "Last good elset" 
would go a long way toward confirming the "misidentification" hypothesis. 
Equally, it would be wonderful to know how bright the "New, from OIG" 
object is. 
 
It is ironic that just as observations are most needed, the usual tools 
and procedures experience difficulties.  Murphy's what?? 
 
Cheers. 
 
Walter Nissen                   dk058@cleveland.freenet.edu 
-81.8637, 41.3735, 256m elevation 
 
--- 
 
New, from OIG: 
IRIDIUM 48 
1 25107U 97082D   99103.00495892  .02386497  00000-0  21460+0 0  2905 
2 25107  86.3956 149.8565 0044142 336.1933  23.6939 14.91443617 68719 
IRIDIUM 48 
1 25107U 97082D   99102.93785409  .02403731  00000-0  21749+0 0  2891 
2 25107  86.3960 149.8891 0043689 336.1246  23.7625 14.91182322 68703 
IRIDIUM 48 
1 25107U 97082D   99102.87074221  .02346858  00000-0  21475+0 0  2888 
2 25107  86.3976 149.9243 0041960 333.8877  26.0291 14.90865740 68690 
IRIDIUM 48 
1 25107U 97082D   99102.53500573  .02123713  00000-0  20105+0 0  2876 
2 25107  86.3990 150.0790 0040177 335.5690  24.3767 14.89307669 68640 
IRIDIUM 48 
1 25107U 97082D   99102.13165883  .01932700  00000-0  19174+0 0  2869 
2 25107  86.4011 150.2646 0040122 337.8921  22.0639 14.87754062 68586 
 
Last good elset for Iridium 48: 
Iridium 48       3.0  0.0  0.0  6.0 d            780 x 775 km 
1 25107U 97082D   99086.69162521 -.00000018  00000-0 -13567-4 0  2489
2 25107  86.4037 156.9570 0003287  61.1570 298.9954 14.34216903 66335