The Mars 2020 SPICE Data Archive
========================================================================

   Last update: July 22, 2022


Introduction
============

   This document describes the Mars 2020 SPICE archive, containing
   observation geometry and other ancillary data in the form of SPICE
   System kernel files for the Mars 2020 rover and its instruments and
   structures. It describes the archive directory structure, kernels 
   included in the archive, their naming conventions, and provides 
   pointers to the SPICE software and documentation.


Table of Contents
=================

   Introduction
   Table of Contents
   Overview
   Errata
   Archive Contents
   Kernel Types
   Archived Kernel Details
      SPK Files
      PCK Files
      IK Files
      CK Files
      LSK Files
      SCLK Files
      FK Files
      MK Files
   Miscellaneous Files
      Checksum Files
   File Formats
   SPICE Software and Documentation
   Contact Information
   Cognizant Persons



Overview
========

   This archive includes the complete set of the Mars 2020 Perseverance 
   Rover Mission data files (kernel files), which can be accessed using
   SPICE software. The SPICE data contain geometric and other ancillary
   information needed to recover the full value of science instrument
   data. In particular SPICE kernels provide spacecraft and planetary
   ephemerides, spacecraft and instrument orientation, instrument
   mounting alignments, and data needed for relevant time conversions.
   Data in the SPICE kernel files must be accessed using the software
   called the SPICE Toolkit produced and distributed by the Navigation
   and Ancillary Information Facility (NAIF) Node of the Planetary Data
   System.

   This archive includes data covering from Mars 2020 launch, 2020-07-30,
   through the end time of the latest rover surface traverse position SPK 
   file supplied in the archive. Until the end of the spacecraft lifespan 
   this archive will be accumulating with new data added according to the 
   project archiving plan.

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Errata ====== 1. This document is a simple HTML document. Providing documents in a simple mark-up format was allowed by earlier versions of the PDS4 Standards but became prohibited in later versions starting summer 2015. Since using HTML documents was compliant at the time when a similar document was first provided in the MAVEN PDS4 archive and since NAIF strives to make bundle description document format and style consistent across all archives, this document continues to exist in this archive as an HTML document. 2. The XML labels of the ancillary products have the reference_type attribute of the Internal_Reference association within the Reference_List class of the Context_Area class pointing to the latest archive description document set to "ancillary_to_data" which is not correct. The correct value "ancillary_to_document" could not be used in these labels because it is not available in the PDS4 information model (IM) 1.5.0.0 used by this archive. This value was added to IM only in the version 1.14.0.0. 3. Only a partial structures IK with a few antenna FOVs is included. IKs for other instruments may be added in a future release. 4. The Mars 2020 FK does not define frames for majority of instruments. A more complete FK may be added in a future release. 5. RSM and RA orientation CKs have sparse coverage. CKs with more complete coverage may be added in a future release. 6. No HGA CK is included. HGA CK for initial 90 Sols may be added in a future release. 7. No Helicopter Technology Demonstration Ingenuity kernels are included. SPK, CKs, IKs, and FK updates for the helicopter may be added in a future release. 8. The following SPK and CK files m2020_surf_hga_tlm_0179_0299_v1.bc m2020_surf_ra_tlmenc_0000_0089_v1.bc m2020_surf_ra_tlmenc_0089_0179_v1.bc m2020_surf_ra_tlmenc_0179_0299_v1.bc m2020_surf_ra_tlmres_0000_0089_v1.bc m2020_surf_ra_tlmres_0089_0179_v1.bc m2020_surf_ra_tlmres_0179_0299_v1.bc m2020_surf_rover_tlm_0000_0089_v1.bc m2020_surf_rover_tlm_0089_0179_v1.bc m2020_surf_rover_tlm_0179_0299_v1.bc m2020_surf_rsm_tlmenc_0000_0089_v1.bc m2020_surf_rsm_tlmenc_0089_0179_v1.bc m2020_surf_rsm_tlmenc_0179_0299_v1.bc m2020_surf_rsm_tlmres_0000_0089_v1.bc m2020_surf_rsm_tlmres_0089_0179_v1.bc m2020_surf_rsm_tlmres_0179_0299_v1.bc m2020_surf_rover_loc_0000_0089_v1.bsp m2020_surf_rover_loc_0089_0179_v1.bsp m2020_surf_rover_loc_0179_0299_v1.bsp m2020_surf_rover_tlm_0000_0089_v1.bsp m2020_surf_rover_tlm_0089_0179_v1.bsp m2020_surf_rover_tlm_0179_0299_v1.bsp were erroneously archived in BIG-IEEE binary format. They will be superseded by later-version files in the correct LTL-IEEE binary format in a future archive release.

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Archive Contents ================ Files in this archive are organized into a set of subdirectories below the top-level directory. The following diagram shows the structure and content of these directories. The directory names are enclosed in square brackets ([]). [top-level-directory] | |- bundle_mars2020_spice_v*.xml Bundle PDS4 label, one or more versions. |- readme.txt Bundle top-level readme file. | |-[spice_kernels] Directory containing SPICE kernels. | | | |- collection_spice_kernels_v*.xml PDS4 labels for Spice Kernels collections. | |- collection_spice_kernels_inventory_v*.tab | | Spice Kernels collections' inventories. | | | |-[ck] Directory containing CK files. | | | | | |-- *.bc Binary CK files. | | +-- *.xml PDS4 labels for CK files. | | | |-[fk] Directory containing FK files. | | | | | |-- *.tf Text FK files. | | +-- *.xml PDS4 labels for FK files. | | | |-[ik] Directory containing IK files. | | | | | |-- *.ti Text IK files. | | +-- *.xml PDS4 labels for IK files. | | | |-[lsk] Directory containing LSK files. | | | | | |-- *.tls Text LSK files. | | +-- *.xml PDS4 labels for LSK files. | | | |--[mk] Directory containing MK files. | | | | | |-- *.tm Text Meta-kernel files. | | +-- *.xml PDS4 labels for MK files. | | | |-[pck] Directory containing PCK files. | | | | | |-- *.tpc Text PCK files. | | +-- *.xml PDS4 labels for PCK files. | | | |-[sclk] Directory containing SCLK files. | | | | | |-- *.tsc Text SCLK files. | | +-- *.xml PDS4 labels for SCLK files. | | | +-[spk] Directory containing SPK files. | | | |-- *.bsp Binary SPK files. | +-- *.xml PDS4 labels for SPK files. | |-+-[miscellaneous] Directory miscellaneous files. | | | |- collection_miscellaneous_v*.xml PDS4 labels for miscellaneous collections. | |- collection_miscellaneous_inventory_v*.tab | | Miscellaneous collections' inventories. | | | +-[checksum] Directory containing checksum files. | | | |-- *.tab Text checksum files. | +-- *.xml PDS4 labels for checksum files. | +-[document] Directory containing documents. | |- collection_document_v*.xml PDS4 labels for document collections. |- collection_document_inventory_v*.tab | Document collections' inventories. | |- spiceds_v*.html This file and its earlier versions. +- spiceds_v*.xml PDS4 labels for this file and its earlier versions.

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Kernel Types ============ Different SPICE kernel types are used to store different kinds of ancillary data. SPK (Spacecraft Planet Kernel) files contain ephemerides (position and velocity) for spacecraft, planets, satellites, comets and asteroids as well as for moving or fixed spacecraft and instrument structures. SPK files are located under the spice_kernels/spk directory of this archive. PCK (Planetary Constants Kernel) files contain certain physical, dynamical and cartographic constants for target bodies, such as size and shape specifications, and orientation of the spin axis and prime meridian. PCK files are located under the spice_kernels/pck directory of this archive. IK (Instrument Kernel) files contain instrument parameters relevant for computing an instrument's geometry such as field-of-view definitions, CCD and optical distortion characteristics, and internal timing parameters. IK files are located under the spice_kernels/ik directory of this archive. CK (C-matrix Kernel) files contain time varying orientations for spacecraft, spacecraft structures, and articulating science instruments. CK files are located under the spice_kernels/ck directory of this archive. LSK (Leapseconds Kernel) files contain the leapseconds and the values of other constants required to perform a transformation between Universal Time Coordinated (UTC) and Ephemeris time (ET), which is also known as Barycentric Dynamical Time (TDB). LSK files are located under the spice_kernels/lsk directory of this archive. SCLK (Spacecraft Clock Kernel) files contain on-board clock calibration data required to perform a transformation between Ephemeris time (ET) and spacecraft on-board time (SCLK). SCLK files are located under the spice_kernels/sclk directory of this archive. FK (Frame definitions Kernel) files contain information required to define reference frames, sources of frame orientation data and connections between these frames and other frames supported within the SPICE system. The science instrument frame definitions provided in the FK files include mounting alignment information for the instruments. FK files are located under the spice_kernels/fk directory of this archive. MK (Meta-Kernel) files list sets of related SPICE kernels that should be used together, providing an easy way to make data from these kernel sets available to a SPICE-based application by loading meta-kernels into the program using the high level SPICE data loader routine FURNSH. MK files are located the spice_kernels/mk directory of this archive. Archived Kernel Details ======================= The subsections below provide details, such as file naming conventions and specific details, for each of the kernel types included in this archive.

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SPK Files SPK (Spacecraft Planet Kernel) files contain ephemerides (position and velocity) for spacecraft, planets, satellites, comets and asteroids as well as for moving or fixed spacecraft and instrument structures. This archive includes binary SPK files containing the following kinds of ephemeris data: - planetary ephemeris SPKs These SPKs contain ephemeris data for the Solar System planet barycenters, and Sun, Mercury, Venus, Earth, and Moon, determined by the JPL Solar System Dynamics group and are named DEXXX, e.g. DE430. - Martian satellite ephemeris SPKs These SPKs contain ephemeris data for Mars, Phobos, Deimos, Sun, Earth barycenter, and Earth, determined by the JPL Solar System Dynamics group and are named MARXXX, e.g. MAR097. - reconstructed spacecraft cruise trajectory SPKs These SPKs contain the reconstructed Mars 2020 spacecraft trajectory for cruise determined by the Mars 2020 Navigation (NAV) team, JPL. - reconstructed spacecraft EDL trajectory SPKs These SPKs contain the reconstructed Mars 2020 spacecraft trajectory during Entry Descent Landing (EDL) determined by the Mars 2020 EDL Team, JPL. - actual landing site position SPKs These SPKs contain the actual location of the Mars 2020 landing site in the Mars body-fixed frame (IAU_MARS, based on IAU 2000 Mars rotation constants), determined by the Mars 2020 EDL Team, JPL. - rover at landing site position SPKs These SPKs contain the position of the Mars 2020 rover fixed at the landing site. These files were used during operations by CHRONOS and other applications that were not sensitive to the local rover movements. - structures SPKs These SPKs contain fixed locations of of selected rover structures and instruments such as Remote Sensing Mast (RSM), Robotic Arm (RA), and cameras. The data included in the file are based of dimensions from the spacecraft engineering drawings. - localized rover path and site locations SPKs These SPKs contain the locations of the sites along the path relative to the center of Mars and the location of the rover relative to the center of Mars, created by the NAIF, JPL. These SPKs were created using localized data available in the PLACES server developed and maintained by the Mars 2020 Operations Product Generation Subsystem (OPGS) Team. The set of localized data in the PLACES server included rover and site location data for a limited set of localization points determined by tracing the rover traverse on high resolution maps, combined a subset of telemetry products to create a more complete set of location points. Because the telemetry products used in this process included only image headers and mobility summaries, containing rover location during non-motion periods, and did not include data from the high-rate mobility history products containing rover location during motion periods, these SPKs do not provide real data during motion but instead provide interpolated values. In global context the data provided in these SPKs is significantly more accurate than telemetered rover position estimated on-board. Because of this these SPKs should be preferred to the telemetry-based rover path SPKs. - telemetry-tased rover path and site locations SPKs These SPKs contain the locations of the sites along the path relative to the landing site and location of the rover relative to these sites. These SPKs were created using telemetry data available in the PLACES server developed and maintained by the Mars 2020 Operations Product Generation Subsystem (OPGS) Team. The set of telemetry data in the PLACES server included rover and site location data from only a subset of telemetry products containing such information. Specifically, it included data from the product and image headers and mobility summaries, containing rover location during non-motion periods, and did not include data from the high-rate mobility history products containing rover location during motion periods. For this reason, these SPKs do not provide real data during motion but instead provide interpolated values. Because data provided in these SPKs is based on telemetered rover position estimated on-board, these SPKs are only as accurate as that estimate, which, depending on the traverse distances, slippage and sliding, can off by meters. The SPK files are provided under the spice_kernels/spk directory and are named according to the following schemes: - planetary ephemeris SPKs deVVVs.bsp where VVV is the ephemeris version. s (optional) indicates that the original file coverage was shortened to reduce the file size. - Martian satellite ephemeris SPKs marVVVs.bsp where VVV is the ephemeris version. s (optional) indicates that the original file coverage was shortened to reduce the file size. - reconstructed spacecraft cruise trajectory SPKs m2020_cruise_odSSS_vV.bsp where SSS is the orbit determination solution number. V is the version; the file with the latest version supersedes all similarly named files with earlier versions. - reconstructed spacecraft EDL trajectory SPKs m2020_edl_vVV.bsp where VV is the version; the file with the latest version supersedes all similarly named files with earlier versions. - actual landing site position SPKs m2020_ls_opsYYMMDD_iauYYYY_vV.bsp where YYMMDD is the date when the landing site location stored in the file was determined or released. YYYY is the publication year of the IAU Mars rotation model, with which this SPK should be used. V is the version; the file with the latest version supersedes all similarly named files with earlier versions. - rover at landing site position SPKs m2020_atls_opsYYMMDD_vV.bsp where YYMMDD is the date consistent with the corresponding landing site position SPK. V is the version; the file with the latest version supersedes all similarly named files with earlier versions. - structures SPKs m2020_struct_vVV.bsp where VV is the version; the file with the latest version supersedes all similarly named files with earlier versions. - localized rover path and site locations SPKs m2020_surf_rover_loc_SSSS_ssss_vV.bsp where SSSS is the file coverage start SOL. ssss is the file coverage end SOL. V is the version; the file with the latest version supersedes all similarly named files with earlier versions. - telemetry-tased rover path and site locations SPKs m2020_surf_rover_tlm_SSSS_ssss_vV.bsp where SSSS is the file coverage start SOL. ssss is the file coverage end SOL. V is the version; the file with the latest version supersedes all similarly named files with earlier versions. 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 the utility program COMMNT included in the NAIF Toolkit.

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PCK Files PCK (Planetary Constants Kernel) files contain certain physical, dynamical, and cartographic constants for target bodies, such as size and shape specifications, and orientation of the spin axis and prime meridian. This archive includes generic text PCK files produced by NAIF, containing data from the reports of the IAU Working Group on Cartographic Coordinates and Rotational Elements. The generic text PCK version 00010 contains data from the 2009 report. The PCK files are provided under the spice_kernels/pck directory and are named according to the following scheme: - generic text PCKs pckVVVVV.tpc where VVVVV is the version; the file with the largest number is the latest, but the user of PCK data must decide if the latest version, or an earlier version, is appropriate for his/her analysis task. 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.

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IK Files IK (Instrument Kernel) files contain instrument parameters relevant for computing an instrument's observation geometry such field-of-view definitions, CCD and optical distortion characteristics, and internal timing parameters. This archive includes text IK files for Mars 2020 instruments, for which common instrument geometric parameters normally stored in IKs are applicable, such as the rover cameras, a few other rover-mounted instruments and rover mounted antennas. The IK files are provided under the spice_kernels/ik directory and are named according to the following scheme: - instruments and antennae IK files m2020_NAME_vVV.ti where NAME is the instrument acronym: struct (for miscellaneous structures, e.g. antennae) VV is the version; the file with the latest version supersedes all similarly named files with earlier versions. The most detailed description of the data in a text IK file is provided in metadata included inside the description area of the file. This information can be viewed using any text editor program.

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CK Files CK (C-matrix Kernel) files contain time varying orientations for spacecraft, articulating spacecraft structures, and articulating science instruments. This archive includes binary CK files containing the following kinds of orientation data: - reconstructed spacecraft cruise orientation CKs These CKs contain the reconstructed Mars 2020 spacecraft cruise attitude determined on-board and downlinked in spacecraft telemetry, determined by the Mars 2020 Attitude Control System (ACS) Team, JPL. The set of CKs provided by the Mars 2020 ACS Team includes a CK with complete cruise orientation based on H-vector direction without modeling spin, a CK with fully reconstructed orientation based on real-time quaternions covering only communication periods, a CK with high-rate high-accuracy orientation covering only a few very short periods during certain events sugh as: attitude maneuvers, ACS calibration activities, or thruster firing events. - reconstructed spacecraft EDL orientation CKs These CKs contain the reconstructed Mars 2020 spacecraft EDL attitude, from the EDL entry point to landing, determined by Mars 2020 EDL team, JPL. - reconstructed rover surface orientation CKs These CKs contain the orientation of the rover relative to the local level frame, created by NAIF, JPL. These CKs were created using telemetry data available in the PLACES server developed and maintained by the Mars 2020 OPGS Team. The set of telemetry data in the PLACES server included rover orientation data only from a subset of telemetry products containing such information. Specifically, it included data from the product and image headers and mobility summaries, containing rover orientation during non-motion periods, and did not include data from the high-rate mobility history products, containing rover orientation during motion periods. For this reason, these CKs do not provide real data during motion but instead provide interpolated values. Due to incomplete source data these CKs have gaps in coverage, which can be closed, if needed, using the CKSPANIT utility program. - reconstructed articulating structures orientation CKs These CKs contain the orientation of the Remote Sensing Mast (RSM), Robotic Arm (RA), and High Gain Antenna (HGA) relative to the rover frame, created by NAIF, JPL. These CKs were created using telemetry data available in the PLACES server developed and maintained by the Mars 2020 OPGS Team. The set of telemetry data in the PLACES server included structure articulation angle data from only a subset of telemetry products containing such information. Specifically, it included data from the product and image headers and articulation summaries, containing structure articulation angles during non-articulation periods, and did not include data from the high-rate articulation history products, containing structure articulation angles during articulation periods. For this reason, these CKs do not provide real data during articulation but instead provide interpolated values. The sets of CKs for RSM and RA include CKs based on encoder angles (less accurate but more complete) and CKs based on resolver angles (more accurate but less complete). While RSM and HGA CKs based on resolver angles provide accurate orientation matching that computed in the flight software, the RA CKs do not because the simple forward kinematics approach implemented using these CKs and corresponding frame chains does not model flexing of the RA which can lead to end point orientation errors of a degree or more for some RA configurations. Due to incomplete source data these CKs have gaps in coverage, which can be closed, if needed, using the CKSPANIT utility program. The CK files are provided under the spice_kernels/ck directory and are named according to the following scheme: - reconstructed spacecraft cruise orientation CKs m2020_cruise_recon_TYPE_vV.bc where TYPE specifies the basis of the orientation nospin (for H-vector direction without spin) rawrt (for real-time quaternions during comms) raweng (for high-rate quaternions during events) VV is the version; the file with the latest version supersedes all similarly named files with earlier versions. - reconstructed spacecraft EDL orientation CKs m2020_edl_rec_vVV.bc where V is the version; the file with the latest version supersedes all similarly named files with earlier versions. - reconstructed rover surface orientation CKs m2020_surf_rover_tlm_SSSS_ssss_vV.bc where SSSS is the file coverage start SOL. ssss is the file coverage end SOL. V is the version; the file with the latest version supersedes all similarly named files with earlier versions. - reconstructed articulating structures orientation CKs m2020_surf_STRUC_TYPE_SSSS_ssss_vV.bc where STRUC is the articulating structure hga (for High Gain Antenna) ra (for Robotic Arm) rsm (for Remote Sensing Mast) TYPE specifies the basis of the orientation tlmenc (for encoder-based orientation) tlmres (for resolver-based orientation) SSSS is the file coverage start SOL. ssss is the file coverage end SOL. V is the version; the file with the latest version supersedes all similarly named files with earlier versions. The most detailed description of the data in each CK file is provided in metadata included inside the comment area of the file. This information can be viewed using the utility program COMMNT included in the NAIF Toolkit.

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LSK Files LSK (Leapseconds Kernel) files contain the leapseconds and the values of other constants required to perform a transformation between Universal Time Coordinated (UTC) and Ephemeris time (ET), also known as Barycentric Dynamical Time (TDB). This archive includes generic text LSK files produced by NAIF, containing leapsecond information based on the IERS announcements. The generic text LSK version 0012 contains leap second data up to and including the January 1, 2017 leapsecond. The LSK files are provided under the spice_kernels/lsk directory and are named according to the following scheme: - generic text LSKs naifVVVV.tls where VVVV is the version; the file with the latest version supersedes all similarly named files with earlier versions. The most detailed description of the data in a text LSK file is provided in metadata included inside the description area of the file. This information can be viewed using any text editor program.

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SCLK Files SCLK (Spacecraft Clock Kernel) files contain on-board clock calibration data required to perform a mapping between Ephemeris time (ET) and spacecraft on-board time (SCLK). This archive includes text SCLK files containing the following kinds of data: - official Mars 2020 on-board clock correlation SCLKs These SCLKs contain a tabulation of data needed for converting time measurements between ephemeris time (ET) and Mars 2020 spacecraft clock time (SCLK). They are made from similar files -- SCLK/SCET file, or SCLKvSCET file -- produced by mission Time Correlation Subsystem (TCS) team. The official on-board correlation SCLK files used in operations and included in this data set provide correlation that is incorrect in an absolute sense by as much as 3 seconds during surface operations. The main reason for this error is the loose time correlation requirement for surface operations intended to keep backward compatibility between correlation versions and minimize the impact of deployment of the new correlation across the ground data system. - improved Mars 2020 on-board clock correlation SCLKs These improved SCLK files contain on-board clock correlation accurate to a few tens of milliseconds or better, made specifically for archiving to fix large correlation errors present in the official SCLKs. - Local Mean Solar Time (LMST) SCLKs These SCLK files provide a way of converting between the Local Mean Solar Time (LMST) time system used during surface operations and other time systems. LMST was introduced as a replacement of the Local True Solar Time (LTST) because a time system with a constant duration of a second was needed for use in the planning and sequencing processes. The LMST is essentially a linear approximation of the local true solar time with the rate set equal to the mean Mars local second duration and the initial reference point set to LMST midnight of the landing SOL. Due to ellipticity of the Mars orbit this approximation is periodic and deviates from the LTST by as much as 50 minutes during Martian year. The SCLK files are provided under the spice_kernels/sclk directory and are named according to the following scheme: - official Mars 2020 on-board clock correlation SCLKs m2020_168_sclkscet_VVVVV.tsc where VVVVV is the version; the file with the latest version supersedes all similarly named files with earlier versions. - improved Mars 2020 on-board clock correlation SCLKs m2020_168_sclkscet_refit_vVV.tsc where VV is the version; the file with the latest version supersedes all similarly named files with earlier versions. - Local Mean Solar Time (LMST) SCLKs m2020_lmst_opsYYMMDD_vV.tsc where YYMMDD is the date consistent with the corresponding landing site position SPK. V is the version; the file with the latest version supersedes all similarly named files with earlier versions. The most detailed description of the data in a text SCLK file is provided in metadata included inside the description area of the file. This information can be viewed using any text editor program.

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FK Files FK (Frame definitions Kernel) files contain information required to define reference frames, sources of frame orientation data and connections between these frames and other frames supported within the SPICE system. The science instrument frame definitions provided in the FK files include mounting alignment information for the instruments. This archive includes text FK files defining reference frames for the Mars 2020 rover, its structures, and science instruments. These FKs were produced by NAIF using the spacecraft and instrument design documentation as well as actual instrument alignment values determined pre-launch and as the result of in-flight calibrations. The FK files are provided under the spice_kernels/fk directory and are named according to the following scheme: - Mars 2020 mission FK files m2020_vVV.tf where VV is the version; the file with the latest version supersedes all similarly named files with earlier versions. The most detailed description of the data in a text FK file is provided in metadata included inside the description area of the file. This information can be viewed using any text editor program.

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MK Files Meta-kernel (MK) files (a.k.a 'furnsh' files) provide lists of the archived kernels included in this archive suitable for loading into a SPICE-based application via the high level SPICE data loader routine FURNSH. Using meta-kernels makes it easy to load with one call a comprehensive SPICE data collection for a given period. This archive includes the following kinds of MK files: - whole mission MK files These MKs with provide the complete sets of best available kernels. - CHRONOS MK files These MKs provide only kernels needed for the SPICE CHRONOS time-conversion program and include the CHRONOS configuration parameters (spacecraft ID, planet ID, landing UTC, landing SOL index, and Sun GM). These MKs provide the same sets of kernels as they provided during OPS except for the cruise and EDL SPKs. The text MK files are provided under the spice_kernels/mk directory and are named according to the following scheme: - whole mission MK files m2020_vVV.tm when VV is the version; the file with the latest version supersedes all similarly named files with earlier versions. - CHRONOS MK files m2020_chronos_vVV.tm when VV is the version; the file with the latest version supersedes all similarly named files with earlier versions. Although the meta-kernels were created such that on a UNIX workstation they can be loaded into a SPICE-based application directly from the directory in which they reside -- because the PATH_VALUES keyword is set to '..' and '/' is used as the path delimiter -- it is recommended that users make local copies of these files and update the PATH_VALUES keyword in each of them to point to the actual location of the archive's 'spice_kernels' directory on their system. Additional changes including replacing '/' and '\' in all path specifications and converting UNIX line terminators to terminators native to the user's system may be required to use these meta-kernels on non-UNIX workstation. The following guidelines were followed to pick and set priority -- determined by the order in which the kernel files are listed, with the latest one taking precedence -- for the kernel files included in these meta-kernels: - the latest archived versions of LSK, PCK, on-board clock and LMST SCLKs, IKs, FK, planetary ephemeris SPK, satellite ephemeris SPK, cruise SPK, EDL SPK and CK, landing site SPK, localized rover surface path SPK, and rover, RSM, RA, and HGA CKs were included - only the reconstructed cruise CK based on real-time telemetry during communication periods was included. Additional description of the kernels sets listed in a text MK file is provided in metadata included inside the description area of the file. This information can be viewed using any text editor program.

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Miscellaneous Files =================== Miscellaneous files provide value added elements that are outside the scope of the PDS archive requirements. Miscellaneous files included in this archive are currently limited to checksum files. The subsection below provides details for these files.

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Checksum Files A checksum file provides a table of MD5 checksums for all files in the archive as of a particular archive (bundle) version, including checksums for all previous checksums files and their labels but excluding the checksum for the checksum file itself and its label. The checksum files are provided under the miscellaneous/checksum directory and are named according to the following scheme: - Mars 2020 checksum files checksum_vVVV.tab where VVV is the version; the file with the latest version supersedes all similarly named files with earlier versions and can be used to validate the archive in its entirety.

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File Formats ============ All text documents, checksum files, and other meta information files such as descriptions, detached PDS4 labels, and inventory tables, are stream format files, with a carriage return (ASCII 13) and a line feed character (ASCII 10) at the end of the records. This allows the files to be read by most operating systems. The text kernel files in this archive -- LSKs, PCKs, SCLKs, IKs, FKs, and MKs -- are UNIX text files, with a line feed character (ASCII 10) at the end of the line, and binary kernel files -- SPKs and CKs -- are IEEE LSB binary files. While data files in this archive can be used 'as is' with SPICE toolkits for the majority of supported environments, converting the files to the binary or text format native to the user's computer may be required for use of the data with FORTRAN toolkits on incompatible environments. Refer to the documentation provided with the SPICE Toolkit to find out whether conversion is needed in each specific case. NAIF provides a tool (BINGO) that can convert either binary or text kernels from one format to another. This means that text files can have their line terminator changed and binary files can be converted to the native format of the platform of interest. BINGO is available from the utilities page at the NAIF Node of the PDS: https://naif.jpl.nasa.gov/naif/utilities.html

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SPICE Software and Documentation ================================ The latest SPICE Toolkit for a variety of computer platforms, additional utility programs, documentation, tutorials, and hands-on lessons are available at the NAIF Node of the PDS: https://naif.jpl.nasa.gov specifically: Toolkit: https://naif.jpl.nasa.gov/naif/toolkit.html Utilities: https://naif.jpl.nasa.gov/naif/utilities.html Tutorials: https://naif.jpl.nasa.gov/naif/tutorials.html Lessons: https://naif.jpl.nasa.gov/naif/lessons.html

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Contact Information =============================== PDS Navigation and Ancillary Information Facility (NAIF), MAIL STOP 301-121 Jet Propulsion Laboratory California Institute of Technology 4800 Oak Grove Drive Pasadena, CA, 91109-8099 818-354-8136 WWW Site: https://naif.jpl.nasa.gov

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Cognizant Persons ================= This archive was produced by Marc Costa Sitja, Boris Semenov, and Matthew Barnes, Planetary Data System Navigation and Ancillary Information Facility Node, Jet Propulsion Laboratory, Pasadena, California. End of Mars 2020 SPICE archive description.

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