PDS_VERSION_ID          = PDS3
RECORD_TYPE             = STREAM

OBJECT                  = TEXT
   INTERCHANGE_FORMAT   = ASCII
   PUBLICATION_DATE     = 2017-07-01
   NOTE                 = "SP-Kernel Information"
END_OBJECT              = TEXT

END

General information about SPICE SP-kernels
==========================================

   The purpose of the SP-kernel (SPK), which stands for S(pacecraft)
   and P(lanet) Kernel, is to allow ephemerides for any collection of
   solar system bodies, spacecraft or any other objects in 3D space to
   be combined under a common file format, and accessed by a common set
   of subroutines. SP Kernels provide the state of a target relative to
   its center of motion, where ``state'' implies Cartesian position and
   velocity at a requested epoch.

   The SPK format is supported by a collection of subroutines that are
   part of the SPICELIB library, the major component of the SPICE
   Toolkit. These subroutines can be integrated into a user's
   application programs. Information about obtaining the SPICE Toolkit
   is located in the ``software'' subdirectory of the main directory of
   this dataset.

   To use SP-kernels, a Leapseconds Kernel (LSK) is required. Also, to
   use SP-Kernels containing states defined relative to non-inertial or
   project-defined frames, a Frames Kernel (FK) and/or Planetary
   Constants Kernel (PcK) are required.

   Refer to the SPK Required Reading (spk.req) document provided with
   the Toolkit or available from the NAIF Node of the PDS, to get more
   information on how to access SP-kernel data.


Venus Climate Orbiter SP-kernels Provided in This Data Set
==========================================================

   This directory contains the SPICE SP-Kernel files for the Venus
   Climate Orbiter (VCO, also known as PLANET-C and AKATSUKI)
   spacecraft, Venus Climate Orbiter mission target Venus. All files
   are in IEEE little endian binary format. The following files are
   present in this directory. (Only the leading portions of the file
   names are shown; the file name extensions of the binary SPK files
   are always ``.bsp''):

      vco_YYYY_vVV        SPK files containing the trajectory of the
                          Venus Climate Orbiter spacecraft relative
                          to the sun or Venus barycenter, mostly
                          created during operations by the ISAS orbit
                          determination group, JAXA. Most of source
                          data for 2010 and for some periods around
                          orbital maneuvers in 2015 were created by
                          the NASA JPL Navigation Team. YYYY in the
                          file name that represents the year identify
                          the period covered by the file.

      vco_de423_de430     vco_de423_de430 combined planetary ephemeris
                          SPK containing data from both de423 and
                          de430. This kernel contains the results of
                          merging portions of DE423 with DE430, to
                          produce a single SPK file that should be
                          valid for the bulk of the entire Venus
                          Climate Orbiter mission.


Kernel File Details
===================

   The most detailed description of the data in each SPK file is
   provided in metadata included inside the comment area of the file.
   This information can be viewed using the utility programs COMMNT and
   SPACIT included in the SPICE Toolkit.