 
 
Stardust Antenna and Center of Gravity SPK File
================================================================================
 
   This SPK file contains location of various SDU antennas and spacecraft
   center of gravity (CG is provided for a few s/c configurations and
   amounts of propellant.)
 
 
Version and Date
--------------------------------------------------------
 
   Version 1.0 -- June 9, 1999
 
      Initial Release.
 
 
Contact Information
----------------------------------------------------------------------
 
   Boris V. Semenov, NAIF/JPL, (818)-354-8136, bsemenov@spice.jpl.nasa.gov
 
 
References
----------------------------------------------------------------------
 
   1. Information provided by LMA SCOPS Team (William R Adams, Gregory E
      Hegemann, Denise N Kato, Stephen M Micciche) to JPL SDU NAV Team
      during e-mail exchange in February and June 1999.
 
   2. ``Frames Required Reading''
 
   3. ``SP-Kernel Required Reading''
 
   4. ``C-Kernel Required Reading''
 
 
Related SPICE Kernels
----------------------------------------------------------------------
 
   Descriptions/definitions from the SDU Frames Kernel (FK) file are
   required in order to understand objects and frames with respect to
   which the locations are defined in this SPK file.
 
 
Coordinates
----------------------------------------------------------------------
 
   This table contains coordinates of various anennas and s/c center of
   gravity with respect to the spacecraft frame. Distances are given in
   centimeters:
 
     STRICTURE      ID     CENTER     FRAME         X,cm     Y,cm     Z,cm
   -------------  -------  ------ --------------  --------  -------  -------
   S/C FRAME CTR  -29000  -29     SDU_SPACECRAFT   113.530    0.050   -2.720
   HGA            -29210  -29000  SDU_SPACECRAFT  -120.447    -.333   50.803
   MGA            -29211  -29000  SDU_SPACECRAFT   -88.000   42.819   24.332
   LGA +Y (LGA1)  -29212  -29000  SDU_SPACECRAFT  -179.037   46.215  -17.720
   LGA -Y (LGA3)  -29213  -29000  SDU_SPACECRAFT  -178.498  -46.536  -18.259
   LGA +Z (LGA2)  -29214  -29000  SDU_SPACECRAFT  -146.560   26.543   43.088
 
   Same in km:
 
      ID     CENTER   FRAME                   X,km       Y,km        Z,km
   -------  -------  --------------------  ---------  ----------  ----------
   -29000   -29      SDU_SPACECRAFT         0.001135    0.000001   -0.000027
   -29210   -29000   SDU_SPACECRAFT        -0.001204   -0.000003    0.000508
   -29211   -29000   SDU_SPACECRAFT        -0.000880    0.000428    0.000243
   -29212   -29000   SDU_SPACECRAFT        -0.001790    0.000462   -0.000177
   -29213   -29000   SDU_SPACECRAFT        -0.001785   -0.000465   -0.000183
   -29214   -29000   SDU_SPACECRAFT        -0.001466    0.000265    0.000431
 
 
   The offsets of the antenna phase centers were estimated from the Mass
   Prop's Model File for the using the following assumptions regarding the
   phase center location with respect to the antenna structure:
 
      -- The low gain antennas it is in the center of the square patch
         surface.
 
      -- For the MGA (Conical Horn Antenna) the phase center is about 5.5"
         interior to the aperture in the center. In other words, starting
         at the center of the circular mouth of the horn, about 5.5 inches
         into the horn along the center axis of the horn.
 
      -- For the HGA the phase center in the middle of the little feed horn
         that looks "down" on the surface of the dish. This is also the focal
         point of the parabolic surface of the dish. Although, any point
         along a line parallel to the spacecraft Z axis and through the center
         of the dish can be used..
 
   The offset for the spacecraft frame origin (-29000) given with respect
   to the center of gravity (-29) is opposite the offset specified in the
   record 1 below:
 
      1) Solar Arrays Deployed, SRC Stowed, 85 kg (max) propellant on
         -Z side of S/C:
 
               cg X = -113.53 cm
               cg Y =   -0.05 cm
               cg Z =    2.72 cm
 
      2) Solar Arrays Deployed, SRC Stowed, 42.5 kg propellant on -Z
         side of S/C:
 
               cg X = -117.06 cm
               cg Y =   -0.05 cm
               cg Z =    2.99 cm
 
      3) Solar Arrays Deployed, SRC Deployed, 30 kg propellant on -Z side
         of S/C:
 
               cg X = -119.53 cm
               cg Y =   -0.06 cm
               cg Z =    2.35 cm
 
 
Data section of the file.
----------------------------------------------------------------------
 
   \begindata
 
   SDU_SC_ORIGIN_IDCODE             = -29000
   SDU_SC_ORIGIN_CENTER             = -29
   SDU_SC_ORIGIN_FRAME              = 'SDU_SPACECRAFT'
   SDU_SC_ORIGIN_XYZ                = (  0.001135    0.000001   -0.000027 )
 
   SDU_HGA_IDCODE                   = -29210
   SDU_HGA_CENTER                   = -29000
   SDU_HGA_FRAME                    = 'SDU_SPACECRAFT'
   SDU_HGA_XYZ                      = ( -0.001204   -0.000003    0.000508 )
 
   SDU_MGA_IDCODE                   = -29211
   SDU_MGA_CENTER                   = -29000
   SDU_MGA_FRAME                    = 'SDU_SPACECRAFT'
   SDU_MGA_XYZ                      = ( -0.000880    0.000428    0.000243 )
 
   SDU_LGA1_IDCODE                  = -29212
   SDU_LGA1_CENTER                  = -29000
   SDU_LGA1_FRAME                   = 'SDU_SPACECRAFT'
   SDU_LGA1_XYZ                     = ( -0.001790    0.000462   -0.000177 )
 
   SDU_LGA3_IDCODE                  = -29213
   SDU_LGA3_CENTER                  = -29000
   SDU_LGA3_FRAME                   = 'SDU_SPACECRAFT'
   SDU_LGA3_XYZ                     = ( -0.001785   -0.000465   -0.000183 )
 
   SDU_LGA2_IDCODE                  = -29214
   SDU_LGA2_CENTER                  = -29000
   SDU_LGA2_FRAME                   = 'SDU_SPACECRAFT'
   SDU_LGA2_XYZ                     = ( -0.001466    0.000265    0.000431 )
 
   SITES                            = (
                                      'SDU_SC_ORIGIN'
                                      'SDU_HGA'
                                      'SDU_MGA'
                                      'SDU_LGA1'
                                      'SDU_LGA3'
                                      'SDU_LGA2'
                                      )
 
   \begintext
 
 
