Re: GFO/ORBCOMM Obs, 13 Feb 98

rosenberg.eric@Orbcomm.COM
Sat, 14 Feb 98 01:25:44 -0500

     Interesting to note Ron's categorization of objects associated with 
     this week's Taurus launch.
     
     I asked my colleagues in Orbcomm's Flight Dynamics Group what objects 
     were really there (noting Ron's 'Orbcomm deb?') note and the response 
     was that there are five (5) objects: 
     
          GFO
          Orbcomm sat G1 (FM3)
          Orbcomm sat G2 (FM4)
          3rd stage of Taurus rocket.
          DPAF (adapter between GFO and Orbcomm)
        
     There is no Orbcomm debris!

     Eric 
     


______________________________ Reply Separator _________________________________
Subject: GFO/ORBCOMM Obs, 13 Feb 98 
Author:  <SeeSat-L@cds.plasma.mpe-garching.mpg.de> at INTERNET
Date:    13-02-98 06:08


Set up the 8 inch telescope this morning for a nicely spaced in time, 
but close in position, pass of the 98-007 objects.   Timing between 
them was 20-30 seconds and I only had to make a slight change in right 
ascension to get to the next viewing location.
     
The pass, just east of Arcturus, was at 5:25 to 5:27 AM local
or 12:25 UT. References to Name and number are from the elsets below:
     
The first object, #25160, MAY have been fluctuating but I am uncertain 
of that.
     
Second was #25159, an ORBCOMM.  I mad a mental note that it WAS fluctating. 
Seems odd but that was my obs.
     
Third was #25158, another ORBCOMM.  This was different in that it was much 
brighter than all the other objects...possibly 5th magnitude while the others 
were 7-8.
     
The fourth and fifth objects, #25161, and #25157 (GFO), were steady and 
faint but easy to see.  
     
Ron Lee
     
GFO                                              877 x 781 km
1 25157U 98007A   98043.22204666  .00001658  00000-0  83749-3 0    92 
2 25157 107.9867  30.8304 0066621 185.7156 174.3213 14.18883248   246 
Orbcomm FM3                                      875 x 782 km
1 25158U 98007B   98043.85617129  .00000559  00000-0  32121-3 0    80 
2 25158 107.9924  32.1066 0064901 184.8463 175.2089 14.19126064   328 
Orbcomm FM4                                      875 x 781 km
1 25159U 98007C   98043.22160925  .00006853  00000-0  32505-2 0    87 
2 25159 107.9863  30.8344 0064580 185.3871 174.6549 14.19263287   230 
Celestis+Taurus r ?                              873 x 782 km
1 25160U 98007D   98043.78514440 -.00001647  00000-0 -70534-3 0    77 
2 25160 107.9871  31.9634 0063409 184.9644 175.0865 14.19466842   314 
Orbcomm deb ?                                    876 x 782 km
1 25161U 98007E   98043.15140120 -.00004305  00000-0 -19560-2 0   142 
2 25161 107.9875  30.6911 0065373 185.5930 174.4516 14.19006958   224