 
 
DIF and DII SPK file for Tempel 1 Encounter, OPNAV Solution, Version 3
===========================================================================
 
     Created by Dan Kubitschek and Nick Mastrodemos, OPNAV/JPL,
     February 9, 2006. Comments were added by Boris Semenov on
     February 14, 2006.
 
 
Objects in the Ephemeris
--------------------------------------------------------
 
     This file contains ephemeris data for Deep Impact Flyby (DIF)
     spacecraft (NAIF ID -140), Deep Impact Impactor (DII) spacecraft
     (NAIF ID -70), and DI primary mission target comet Tempel 1 (NAIF
     ID 1000093) for the two days period around Tempel 1 encounter on
     the July 4, 2005.
 
 
Approximate Time Coverage
--------------------------------------------------------
 
     The DIF and DII trajectories and comet Tempel 1 ephemerides
     provided in this file cover the following time spans:
 
     Deep Impact Impactor Spacecraft (-70):
 
        COVERAGE BEGIN TIME (TDB):   2005 JUL 03 06:16:04.184
        COVERAGE END TIME (TDB):     2005 JUL 04 05:46:38.184
 
     Deep Impact Flyby Spacecraft (-140):
 
        COVERAGE BEGIN TIME (TDB):   2005 JUL 03 06:16:04.184
        COVERAGE END TIME (TDB):     2005 JUL 05 05:45:34.183
 
     Comet Tempel 1 (1000093):
 
        COVERAGE BEGIN TIME (TDB):   2005 JUL 03 06:16:04.184
        COVERAGE END TIME (TDB):     2005 JUL 05 05:46:38.183
 
     Note that the coverage for DII extends about 1 minute past the
     impact time (2005-Jul-04 05:44:34.200 UTC) with the trajectory
     continuing as if the spacecraft flew through the comet.
 
 
Status
--------------------------------------------------------
 
     This file was created by merging DIF and DII SPKs produced from
     even-spaced comet-relative states using MKSPK utility with the
     comet Tempel 1 SPK generated by Horizons Ephemeris System
     maintained by Solar System Dynamics group at JPL. The merging was
     done using SPKMERGE utility (see SPKMERGE log provided in the
     Appendix 1.)
 
 
Pedigree
--------------------------------------------------------
 
     DII trajectory provided in this SPK represents the reconstruction
     based on 57 ITS OpNav images (stars and comet in ITS
     field-of-view) acquired in the first 22 hrs following release and
     accelerometer telemetry for trajectory integration. The
     trajectory was fit to ITS OpNav images spanning
     2005-JUL-03T06:45:39 -> 2005-JUL-04T02:46:38 (ET). The ITS images
     were processed, by hand, using the pixel and line location of the
     ACTUAL impact site as the observation. The trajectory is
     therefore given relative to the impact site on comet Tempel 1. The
     estimated trajectory was integrated from 2005-JUL-04T02:46:38 ->
     2005-JUL-04T05:46:38.184 (ET) using the on-board accelerometer
     data to capture the Impactor Targeting Maneuvers (ITMs). The
     resulting trajectory was then adjusted, downtrack, to reflect a
     2005-JUL-04T05:44:34.2 (UTC) time-of-impact and adjusted,
     crosstrack, to pass through the ACTUAL impact site.
 
     DIF trajectory provided in this file represents the reconstruction
     based on 50 MRI OpNav images (stars and comet in MRI
     field-of-view) acquired in the 24 hrs following release and ending
     just prior to Flyby time of closest approach. The trajectory was
     fit to MRI OpNav images spanning:  2005-JUL-04T05:45:39 ->
     2005-JUL-04T05:58:59 (ET). The MRI images were processed, by hand,
     using the pixel and line location of the ACTUAL impact site as the
     observation. The trajectory is therefore given relative to the
     impact site on comet Tempel 1. No post-fit adjustments were
     applied to the Flyby trajectory. In this trajectory solution the
     closest approach occurs at approximately 2005-JUL-04T05:58:44.5
     UTC with the flyby distance of about 499 kilometers.
 
     Comet Tempel 1 ephemeris provided in this file were extracted in
     November 2005 from the Horizons system maintained by Solar System
     Dynamics group at JPL.
 
 
Contacts
--------------------------------------------------------
 
     If you have questions regarding this data contact
 
        Dan Kubitschek
        (818)-393-1101
        Daniel.G.Kubitschek@jpl.nasa.gov
 
     or
 
        Boris Semenov
        (818)-354-8136
        Boris.Semenov@jpl.nasa.gov
 
 
Appendix 1: SPKMERGE Log
--------------------------------------------------------
 
; di_finalenc_nav_v3.bsp LOG FILE
 
; Created 2006-02-09/12:05:17.00.
;
; BEGIN SPKMERGE COMMANDS
 
LEAPSECONDS_KERNEL   = /home/kubi/spice/naif0007.tls
 
SPK_KERNEL           = di_finalenc_nav_v3.bsp
  SOURCE_SPK_KERNEL  = Deep_Impact_flyby-cometcenter.bsp
    INCLUDE_COMMENTS = NO
    BODIES           = 1000093
    BEGIN_TIME       = 2005 JUL 03 06:15:00.000
    END_TIME         = 2005 JUL 05 05:45:34.000
  SOURCE_SPK_KERNEL  = Deep_Impact_flyby-cometcenter.bsp
    INCLUDE_COMMENTS = NO
    BODIES           = -140
    BEGIN_TIME       = 2005 JUL 03 06:15:00.000
    END_TIME         = 2005 JUL 05 05:44:30.000
  SOURCE_SPK_KERNEL  = imp-recon-cometcenter3.bsp
    INCLUDE_COMMENTS = NO
    BODIES           = -70
    BEGIN_TIME       = 2005 JUL 03 06:15:00.000
    END_TIME         = 2005 JUL 04 05:45:34.000
 
; END SPKMERGE COMMANDS
 
 
 
