Feb 14, 2012    C. Acton

Unless you are trying to exactly replicate results produced at some earlier time you should 
use the latest generic text PCK available from NAIF. This will be found under the 
generic_kernels folder on the naif server here:  /pub/naif/generic_kernels/pck. 
It will have a name style like:  pck000xx.tpc  for exammple, pck00010.tpc.