Load an ephemeris file for use by the readers.  Return that file's 
   handle, to be used by other SPK routines to refer to the file.

   Variable  I/O  Description
   --------  ---  --------------------------------------------------
   fname      I   Name of the file to be loaded.
   handle     O   Loaded file's handle.

   fname          is a string containing the name of the file to be 
                  loaded.

   handle         is an integer handle assigned to the file upon 
                  loading.   Almost every other SPK routine will 
                  subsequently use this number to refer to the file.

   Loading an SPK file make the file's data accessible to the CSPICE
   SPK readers spkezr_c and spkez_c.  

   The maximum number of SPK files that may be loaded at any time is
   given by the parameter FTSIZE, which is defined in the header file
   cspicelimits.h.  After this limit it reached, it is necessary to
   unload an SPK file before another can be loaded.  The function
   spkuef_c is provided to unload files from the SPK system.

   1)  Load a planetary ephemeris SPK; then look up a series of
       geometric states of the Earth relative to the solar system 
       barycenter, referenced to the J2000 frame.


            #define        MAXITR        100
            #define        ET0           -315576000.0
            #define        STEP          3600.0

            #define        ABCORR        "NONE"
            #define        FRAME         "J2000"
            #define        OBSERVER      "SOLAR SYSTEM BARYCENTER"
            #define        SPK           "de403.bsp"
            #define        TARGET        "EARTH"

            SpiceInt       handle;
            SpiceInt       i;

            SpiceDouble    et;
            SpiceDouble    lt;
            SpiceDouble    state [6];


         /.
            Load the spk file.
         ./
            spklef_c ( SPK, &handle );

         /.
            Step through a series of epochs, looking up a state vector
            at each one.
         ./ 
            for ( i = 0;  i < MAXITR;  i++ )
            {
               et  =  ET0 + i*STEP;

               spkezr_c ( TARGET,    et,     FRAME,  ABCORR, 
                          OBSERVER,  state,  &lt             );

               printf( "\net = %20.10f\n\n",                 et       );
               printf( "J2000 x-position (km):   %20.10f\n", state[0] );
               printf( "J2000 y-position (km):   %20.10f\n", state[1] );
               printf( "J2000 z-position (km):   %20.10f\n", state[2] );
               printf( "J2000 x-velocity (km/s): %20.10f\n", state[3] );
               printf( "J2000 y-velocity (km/s): %20.10f\n", state[4] );
               printf( "J2000 z-velocity (km/s): %20.10f\n", state[5] );
            }

   None.

   The parameter FTSIZE referenced below is defined in the header file
   cspicelimits.h.

   1) If an attempt is made to load more files than is specified
      by the parameter FTSIZE, the error "SPICE(SPKFILETABLEFULL)" is
      signalled.

   2) If an attempt is made to open more DAF files than is specified
      by the parameter FTSIZE, an error is signalled by a routine that 
      this routine calls.

   A file specified by fname, to be loaded.  The file is assigned a
   handle by spklef_c, which will be used by most other routines to
   refer to it.

   N.J. Bachman    (JPL)
   K.R. Gehringer  (JPL)
   J.M. Lynch      (JPL)
   R.E. Thurman    (JPL)
   I.M. Underwood  (JPL)

   NAIF Document 168.0, "S- and P- Kernel (SPK) Specification and
   User's Guide"

   -CSPICE Version 2.0.0, 08-FEB-1998 (NJB)  

       Input argument filename changed to type ConstSpiceChar *.
       References to C2F_CreateStr_Sig were removed; code was
       cleaned up accordingly.  String checks are now done using
       the macro CHKFSTR. 

   -CSPICE Version 1.0.0, 25-OCT-1997 (NJB) (EDW)

   load spk ephemeris file