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. SPK can be accessed by subroutines that are part of the SPICE library, the major component of the SPICE Toolkit. These subroutines can be integrated into user application programs. For information on the SPICE toolkit and/or how to obtain it, please consult SPICE_INST.CAT and SOFT.CAT. To use SP-kernels, a Leapseconds (LSK) is also required. To use SP-Kernels containing positions given relative to the non-inertial and project-defined frames, Frame Definitions Kernel (FK), Planetary Constants Kernel (PcK), and C-Kernel (CK) files are also required. Refer to the SPK.REQ document provided with the Toolkit to get more information on how to access SP-kernel data. ROSETTA SPK Files ================= This file describes the contents of the DATA/SPK directory of the ROSETTA SPICE dataset. Some of these SPK files are produced by an automated system located at ESTEC, operated by the ROSETTA Science Operations Center (RSOC). For these we have chosen to use the ESOC naming convention for SPK files, which are converted from ESOC's DDID Orbit files. The contents and time span covered by any SPK file may be easily determined using the 'brief' utility program available in all copies of the SPICE Toolkit. Examples of usage: %brief %brief <*.bsp> %brief Descriptive information about how/why/when an SPK file was created is usually available in the 'comment area' of the file. This may be viewed using the 'commnt' utility program available in all copies of the SPICE Toolkit. Use the '-r' option to read the comments. Example: %commnt -r All binary SPK files (*.BSP) contained in this directory are unix binary files. These may be used as is (without format conversion) in a non-unix environment when using any recent version of the SPICE Toolkit (Version N0052 or later). ROSETTA SPK-Kernels Contained in this Data Set ============================================== The following SPK-kernels are provided in this data set: DE405.BSP Contains ephemeris data for planet barycenters, and for the Sun, planets and satellites mass centers. Covers a long enough period for the Rosetta Mission. EARTHSTNS_FX_050714.BSP Contains ephemeris data for NASA DSN stations relative to the terrestrial reference frame ITR93. In the interest of flexibility, in this file the reference frame is labelled with the alias 'EARTH_FIXED'. Any application using this file must map the alias 'EARTH_FIXED' to either 'ITR93' or 'IAU_EARTH'. This file was released on yy-mm-dd. EARTHSTNS_ITRF93_050714.BSP Contains ephemeris data for NASA DSN stations relative to the terrestrial reference frame label 'ITR93'. This file was released on yy-mm-dd. NEW_NORCIA.BSP Contains ephemeris data for the ESA New Norcia station. TEMPEL1_9P_DI_P.BSP Contains predicted ephemeris for the comet Tempel-1/9P courtesy of Deep Impact Team. These ephemeris were compute just before the impact. Spans from May 2005 to September 2005. 21_LUTETIA_2004_2016.BSP Contains predicted ephemeris for the asteroid Lutetia. 67P_CHURY_GERAS_2004_2016.BSP Contains predicted ephemeris for the comet 67 P/Churyumov-Gerasimenko. This file is generated and provided by NAIF. Either this file or ORHW_______________00016.BSP can be safely used, although this one spans a slightly shorter period of time. ORER_______________vvvvv.BSP Contains Rosetta spacecraft reconstructed ephemeris of 1st Earth flyby. Spans the 1st Earth flyby period. These ephemeris corresponds to the ESOC orbit file named: ORER_FDLRMA_DA______________vvvvv.ROS where vvvvv designates the version number. ORFR_______________vvvvv.BSP Contains Rosetta spacecraft predicted ephemeris of 2nd Earth flyby. Spans the 2nd Earth flyby period. These ephemeris corresponds to the ESOC orbit file named: ORFR_FDLRMA_DA______________vvvvv.ROS where vvvvv designates the version number. ORGR_______________vvvvv.BSP Contains Rosetta spacecraft predicted ephemeris of 3rd Earth flyby. Spans the 3rd Earth flyby period. These ephemeris corresponds to the ESOC orbit file named: ORGR_FDLRMA_DA______________vvvvv.ROS where vvvvv designates the version number. ORHO_______________vvvvv.BSP Contains predicted ephemeris for the asteroid 2867 Steins, using ephemeris provided by ESOC. ORHR_______________vvvvv.BSP Contains Rosetta spacecraft predicted and reconstructed cruise ephemeris. Spans the cruise phase, from launch to comet rendezvous maneouver. These ephemeris corresponds to the ESOC orbit file named: ORHR_FDLRMA_DA______________vvvvv.ROS where vvvvv designates the version number. ORHS_______________vvvvv.BSP Contains ephemeris for the asteroid Lutetia, that corresponds to the ESOC orbit file ORHS_FDXRMY_DA______________vvvvv.ROS, where X can be R or L, Y can be A or B, and vvvv is the version number. ORHW_______________vvvvv.BSP Contains predicted ephemeris for the comet 67 P/Churyumov-Gerasimenko. Unlike the file above, this file was generated by ADCS using ESOC Flight Dynamics data. Either this file or 67P_CHURY_GERAS_2004_2016.BSP can be safely used, although this one spans a slightly wider period of time. ORMR_______________vvvvv.BSP Contains Rosetta spacecraft predicted ephemeris of Mars flyby. Spans the Mars flyby period. These ephemeris corresponds to the ESOC orbit file named: ORMR_FDLRMA_DA______________vvvvv.ROS where vvvvv designates the version number. OUTERPLANETS_Vvvvv.BSP Kernel with ephemeris data for the solar system outer planets (jupiter, saturn, uranus and neptune). 2867_STEINS_2004_2016.BSP Contains predicted ephemeris for the asteroid 2867 Steins. This file is generated and provided by NAIF. ROS_STRUCT_Vv.BSP This SPK file contains location of various Rosetta structures and instruments. Note: Files EARTHSTNS_FX_050714.BSP and EARTHSTNS_ITRF93_050714.BSP contain the same data. These files only differ in that the second one use the reference frame label 'ITR93' instead of 'EARTH_FIXED'. 'EARTH_FIXED' alias must be map to either 'ITR93' or 'IAU_EARTH' before using the file. For high accuracy work, the EARTHSTNS_ITRF93_yymmdd.BSP is recommended (on the basis of ease of use). Please note as well that when different versions of the same kernel are provided, the one with a higher verion number supersedes the other(s). 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 in the SPICE Toolkit. At least a basic knowledge of the SPICE system is needed in order to use this kernels. The SPICE toolkit provides versions in Fortran (SPICELIB), C (CSPICE) and IDL (icy), and the user can choose any one that suits him/her. The SPICELIB routine FURNSH, CSPICE function furnsh_c, and icy routine cspice_furnsh load a kernel file into the kernel pool as shown below. CALL FURNSH ( 'kernel_name' ) furnsh_c ( ''kernel_name'' ); cspice_furnsh, 'kernel_name' In the case when two or more files contain data overlapping in time for a given object, for binary kernels, the file loaded last takes precedence. If two (or more) text kernels assign value(s) using the '=' operator to identical keywords, the data value(s) associated with the last loaded occurrence of the keyword are used -all earlier values have been replaced with the last loaded value(s).