PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM LABEL_REVISION_NOTE = " SwRI:BLEnke 2020-04-01 Updated for Release 0005 delivery - added note about hand-edits in v003 of the nh_stars* file. SwRI:BLEnke 2021-04-15 Updated for Release 0006 delivery - added nh_pcnh_008 to fix typo in radius of Styx. SwRI:BLEnke 2024-03-14 Updated for Release 0007 delivery - added nh_pcnh_010 to revise Pluto system constants. - added nh_arrokoth_001 to document the best Arrokoth constants. - added nh_stars_kbo_centaur_v0004 for new distant KBOs. - added pck00011.tpc with updates through 2022. " OBJECT = TEXT INTERCHANGE_FORMAT = ASCII PUBLICATION_DATE = 2021-04-15 NOTE = "PC-Kernel Information" END_OBJECT = TEXT END General information about SPICE PC-kernels ========================================== In the SPICE system, the PC-kernels contain planetary attitude and body shape information. The PCK kernel includes orientation and shape information pertaining to extended solar system bodies such as the Sun, the planets, the natural satellites of the planets, comets, and asteroids. The most recent PC kernel file can always be obtained from NAIF/JPL. The purpose of the PCK kernels and associated software is to provide SPICE users with a convenient mechanism for supplying planetary physical constants to application programs. SPICELIB's PCK software is able to read files conforming to the PCK format and return to a calling application program both the data contained in such files and a small number of commonly used numeric quantities derived from the kernel data. The SPICE system toolkit for a number of computer platforms or information regarding how it can be obtained is located in the SOFTWARE subdirectory of the main directory of this dataset. Refer to the PCK.REQ document provided with the toolkit or available from the NAIF Node of PDS if SPICE toolkit is not included with this data set to get more information on how to access PC-kernel data. New Horizons PC-kernels Provided in This Directory ================================================= This directory contains PCK files used by New Horizons project. All files are in IEEE text format and must be copied using ftp ASCII transfer to any non-UNIX workstation. The following files are present in this directory. (Only file names are shown; the file name extensions of the text PCK kernel files are always ".tpc"): pck00008 Generic SPICE PCK file providing IAU/IAG/COSPAR values accepted in 2000; as of Release 0002 this file is obsolete; pck00010 Generic SPICE PCK file providing IAU/IAG/COSPAR values accepted in 2009; pck00011 Generic SPICE PCK file providing IAU/IAG/COSPAR values accepted in 2022; N.B. For operational reasons the NH project continued to use the pck00008.tpc file throughout the Pluto encounter; geometry stored within observational data files (PDS labels; FITS headers) will list the SPICE kernels used to retrieve the ephemerides and make the geometry calculations. nh_arrokoth_001 Generic SPICE PCK file providing revised radii values, poles, and Euler angles for ASTEROID 486958 (2014 MU69). The original SOC file name was pck_arrokoth_001 . nh_pcnh_007 Generic SPICE PCK file providing revised radii values, poles, and Euler angles for some Pluto system objects beyond what is available in pck00011; nh_pcnh_008 Generic SPICE PCK file. Same as nh_pcnh_007 plus a fix for a typo in the radius of Styx. nh_pcnh_010 Generic SPICE PCK file. Same as nh_pcnh_008 plus numerous science team updates to the Pluto/Charon and small satellite radii, poles, and Euler angles. Restored Nix and Hydra RA/DEC and PM values from nh_pcnh_008 and moved a new, probably wrong set of values into comments, pending clarification from the science team. nh_stars_kbo_centaur_vNNN This PCK was generated by the Science Operation Center (SOC) to provide SPICE ID to name tranlation for bodies not covered by the project kernels. It was also used as an input to the SPICE utility PPINP to generate pseudo-bodies to represent stars observed by the New Horizons spacecraft. Refer to the metadata and comments in that file for more detail. The _vNNN suffix on the filename, before the .tpc extension, is a version number, starting with v001. The original suffix on the SOC file version was _ppinp. v003 adds information for new distant KBOs. It also contains hand-edits needed by the SOC data pipelines to resolve pole usage errors and perform distance calculations. v004 adds information for new distant KBOs. It also updates the Arrokoth prime meridian and body radius values. Kernel file details =================== The most detailed description of the data in a text PCK file is provided in metadata included inside the description area of the file. This information can be viewed using any text editor program. The most detailed description of the data in a binary PCK file is provided in metadata included inside the comment area of the file. This information can be viewed using utility programs COMMNT and SPACIT included into the NAIF Toolkit.