Essaim 3 E24 discovered by Kevin Fetter

From: Ted Molczan (ssl3molcz@rogers.com)
Date: Wed Feb 06 2013 - 04:59:00 UTC

  • Next message: Kevin Fetter: "Re: Essaim 3 E24 discovered by Kevin Fetter"

    Kevin Fetter observed an UNID that I have identified as Essaim 3 E24 (04049E / 28496):
    
    http://satobs.org/seesat/Feb-2013/0024.html
    
    Kevin intended to post his observations, but seems to have forgotten to include them. Here is the TLE he fit to them:
    
    1 99999U          13035.96631388  .00000400  00000-0  50000-4 0    07
    2 99999  98.3168  65.2854 0011742 315.8390  91.9980 14.82402441    02
    
    Greg Roberts spotted the same object last July, which he suspected was 83060C / 14139. Here are his observations, with
    the correct ID:
    
    28496 04 049E   0433 F 20120713174806650 55 15 1307007+244228 19
    28496 04 049E   0433 F 20120713174816796 55 15 1305495+265204 19
    28496 04 049E   0433 F 20120713174821854 55 15 1305103+275252 19
    28496 04 049E   0433 F 20120713174831916 55 15 1304041+294626 19
    
    When Kevin posts his observations, it may be possible to improve his orbit, by including Greg's observations.
    
    I based my identification on the orbits of the four Essaim satellites following their decommissioning in 2010 October,
    as reported in the following paper:
    
    http://www.spaceops2012.org/proceedings/documents/id1266472-Paper-001.pdf
    
    The results for each satellite are appended to this message. There are three TLEs per satellite. The first is the last
    known orbit prior to decommissioning, derived from hobbyist observations. The second is the result of propagating the
    first orbit to the approximate time of the final decommissioning manoeuvre, using Mike McCants' int2 program, and then
    assuming instantaneous change to the final eccentricity and mean motion. The third TLE is the result of propagating the
    second one to the approximate epoch of Kevin's observation, using int2. Since the second and third TLEs are estimates,
    their catalogue number has been altered to reduce the risk of their being mistaken for TLEs from observations.
    
    The propagated Essaim 3 E24 TLE is very similar in RAAN and mean motion to the one Kevin derived from his observations.
    I recommend using Kevin's TLE to recover Essaim 3, since it should be reasonably predictive. Mine is not predictive, so
    should not be used for the recovery.
    
    I used int2 for the propagations because it accurately models solar gravity perturbations, which significantly affect
    sun-synchronous orbits.
    
    If I understood the above paper correctly, the Essaim are in frozen orbits, with argument of perigee near 270 deg. Int2
    appears not to propagate frozen orbits reliably, and I made no effort to adjust the final results.
    
    The remaining three objects could be discovered using my propagated elements, by means of a planar search. My estimated
    TLEs are not predictive, so a planar search absolutely is required. I would not be surprised if one or more have been
    spotted in recent years as UNIDs, so if time permits I may check past UNIDs for correlations.
    
    Ted Molczan
    
    Essaim 1 W23
    1 28494U 04049C   10078.14364266  .00000000  00000-0  00000-0 0    05
    2 28494  98.2800  46.2358 0003758 100.0011 260.1619 14.70167000    01
    1 78494U 04049C   10287.29238483  .00000600  00000-0  88972-4 0    03
    2 78494  98.3033 259.0155 0011630 158.8992 200.9893 14.75120000    01
    1 78494U 04049C   13035.97110678  .00000664  00000-0  96694-4 0    07
    2 78494  98.3493  50.2927 0010213 349.7093  10.2637 14.75942268    04
    
    Essaim 2 W11
    1 28495U 04049D   10078.14410210  .00000000  00000-0  00000-0 0    07
    2 28495  98.2800  46.1004 0004638  90.0000 270.1725 14.70167382    05
    1 78495U 04049D   10280.35064607  .00000650  00000-0  89651-4 0    09
    2 78495  98.3014 251.8087 0010460 170.8296 189.0669 14.78225000    03
    1 78495U 04049D   13035.97860405  .00000581  00000-0  78528-4 0    02
    2 78495  98.3421  54.3392 0011107 325.9098  33.9985 14.79086885    07
    
    Essaim 3 E24
    1 28496U 04049E   10091.34792659  .00000000  00000-0  00000-0 0    05
    2 28496  98.3090  64.3581 0010000  59.4702 300.7489 14.70158874    01
    1 78496U 04049E   10279.39896266  .00000700  00000-0  90150-4 0    08
    2 78496  98.3271 256.2958 0012500 185.4986 174.3864 14.81100000    00
    1 78496U 04049E   13035.99698442  .00000572  00000-0  72199-4 0    03
    2 78496  98.3402  65.3759 0009522 325.9896  33.9291 14.81989447    09
    
    Essaim 4 E12
    1 28497U 04049F   10091.34746670  .00000000  00000-0  00000-0 0    08
    2 28497  98.3146  64.4169 0013000  49.4724 310.7611 14.70158768    03
    1 78947U 04049F   10287.29352680  .00000650  00000-0  93066-4 0    07
    2 78947  98.3348 264.5546 0012000 150.6790 209.2677 14.76620000    04
    1 78497U 04049F   13035.95143143  .00000803  00000-0  11237-3 0    05
    2 78497  98.3547  60.1610 0014283 336.1683  23.7514 14.77626980    07
    
    
    
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