s fictitious;
          you must supply the name of an SPK file available 
          on your own computer system.
          ./
          #define        SPK           &quot;planetary_spk.bsp&quot;

          /.
          ET0 represents the date 2000 Jan 1 12:00:00 TDB.
          ./
          #define        ET0           0.0

          /.
          Use a time step of 1 hour; look up 100 states.
          ./
          #define        STEP          3600.0
          #define        MAXITR        100 

          #d