PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM OBJECT = TEXT INTERCHANGE_FORMAT = ASCII PUBLICATION_DATE = 2019-02-21 NOTE = "DAWN SP-Kernel Information" END_OBJECT = TEXT END General Information About SPICE SP-Kernels ========================================== The purpose of the SP-kernel -- 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. The SPK files can be accessed and manipulated using the SPICE Toolkit APIs, calls to which can be integrated into user application programs. The information regarding how to obtain the SPICE system toolkit for a number of languages and computer platforms is located in the ``/software'' subdirectory of the main directory of this data set. To use SP-kernels, a Leapseconds (LSK) is required. Also, to use SP-Kernels containing positions given relative to the non-inertial and project-defined frames, a Frame Definitions (FK) and Planetary Constants (PCK) files are required. Refer to the ``spk.req'' document provided with the toolkit to get more information on how to access SP-kernel data. DAWN SP-kernels Provided in This Data Set ========================================= The following DAWN SP-kernels are provided in this data set (only the name portion of the file name is shown; the extension of all file names is ``.bsp''): DAWN Spacecraft Trajectory SPK files: dawn_rec_BEG_END_DEL_vV SPK files containing the reconstructed DAWN trajectory determined by the DAWN NAV team, covering from BEG to END, created on DEL, with version V. All three dates are specified in the YYMMDD format. Note that in the original SPK names the BEG and END tokens were separated by '-' rather than '_'; this had to be changed for the archive to make the names PDS-compliant. Also, note that for the asteroid orbital phases the trajectory provided in these SPKs is asteroid-centric, meaning that the latest asteroid ephemeris SPK must be loaded together with these SPKs in order to compute the s/c position relative to the Sun or other Solar system bodies. dawn_grv_BEG_END_DEL_vV SPK files containing the reconstructed DAWN trajectory determined by the DAWN Gravity team, covering from BEG to END, created on DEL, with version V. All three dates are specified in the YYMMDD format. Note that for the asteroid orbital phases the trajectory provided in these SPKs is asteroid-centric, meaning that the latest asteroid ephemeris SPK must be loaded together with these SPKs in order to compute the s/c position relative to the Sun or other Solar system bodies. dawn_ssd_BEG_END_vV SPK files containing the reconstructed DAWN trajectory determined by the Solar System Dynamics group, JPL, covering from BEG to END, with version V. All three dates are specified in the YYMMDD format. Note that for the asteroid orbital phases the trajectory provided in these SPKs is asteroid-centric, meaning that the latest asteroid ephemeris SPK must be loaded together with these SPKs in order to compute the s/c position relative to the Sun or other Solar system bodies. dawn_p_BEG_END_DEL_vV SPK files containing the predicted DAWN trajectory extending beyond the end of the mission generated by the DAWN NAV team, covering from BEG to END, created on DEL, with version V. All three dates are specified in the YYMMDD format. Note that in the original SPK names the BEG and END tokens were separated by '-' rather than '_'; this had to be changed for the archive to make the names PDS-compliant. DAWN Spacecraft Structures Fixed Offset SPK files: dawn_struct_vV SPK files providing relative locations of various DAWN structures and science and engineering instruments. The file with the latest version number V supersedes all previous versions. Solar System Bodies Ephemeris data SPK file: de421 SPK file containing JPL's Planetary Ephemerides DE421. de432s SPK file containing JPL's Planetary Ephemerides DE432. sb_BODY[_PROD]_DEL SPK file containing the trajectory for BODY, typically 'vesta' or 'ceres'. The producer may be specified by PROD (ex: nav, ssd), and DEL is the date the file was delivered in YYMMDD format. 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 utility programs COMMNT and SPACIT included into the NAIF Toolkit. Contact Information =================== Regarding DAWN project specific information provided in this data set and for general information about SPICE system: Boris Semenov (818)-354-8136 Boris.Semenov@jpl.nasa.gov address: Navigation and Ancillary Information Facility (NAIF) Jet Propulsion Laboratory MS 301-125L 4800 Oak Grove Drive Pasadena CA 91109 USA