The MAVEN SPICE Data Archive

The MAVEN SPICE Data Archive ======================================================================== Last update: May 12, 2021 Introduction ============ This document describes the MAVEN SPICE archive, containing observation geometry and other ancillary data in the form of SPICE System kernel files for the MAVEN spacecraft and its instruments and targets. 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 File Formats SPICE Software and Documentation Contact Information Cognizant Persons Overview ======== This archive includes the complete set of MAVEN SPICE 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 MAVEN launch, 2013-11-18, through the end time of the latest spacecraft orientation 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. No IK file for the STATIC instrument was available at the time of the initial archive release. It was added to the archive in the release 2 (August 2015). 2. All XML labels in the releases 1 (May 2015) and 2 (August 2015) referred to the PDS4 information model version 1.4.0.0 while setting the Primary_Result_Summary purpose attribute to the "Observation Geometry" value, which was added to the model only in version 1.5.0.0. This made these labels non-compliant. During preparation of the release 3 (November 2015) the information model version and references to the model schema and schematron files in the offending labels were changed from 1.4.0.0 to 1.5.0.0 to make them compliant. 3. 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 the document was compliant at the time when its first version was released, it will continue to exist in the archive as an HTML document. 4. Some of the daily IUVS CK files used as input in generating the "v01" merged IUVS CKs covering years 2014-2016 were incomplete, missing 10-20% of data. When this was discovered in May 2017, all merged IUVS CKs for these years were regenerated using the complete daily CKs, and were added to the archive as "v02" files, fully superseding "v01" files. 5. Some of the daily IUVS CK files used as input in generating the "v01" merged IUVS CKs covering from January to March 2021 were incomplete, missing data on 2021-01-22 and 2021-01-24. 6. Some of the reconstructed CK spacecraft and post-deploy Articulating Payload Platform (APP) files present data gaps. When these gaps are significant (when they have a duration of several hours), these data gaps are covered by the corresponding predicted CK files. In the current release these gaps are present on 2014-12-08, 2014-12-26, 2015-03-03, 2015-06-30, 2021-01-14 and 2021-01-15.

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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_maven_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. | +-[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. They are produced 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. They are produced by the JPL Solar System Dynamics group and are named MARXXX, e.g. MAR097. - reconstructed spacecraft trajectory SPKs. These SPKs contain the reconstructed MAVEN spacecraft trajectory determined by the MAVEN Navigation (NAV) team, JPL. - structures SPKs These SPKs contain fixed locations of selected spacecraft structures and science instruments. They are produced by NAIF based on the MAVEN engineering documentation. The SPK files are provided under the spice_kernels/spk directory and are named according to the following schemas: - 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 trajectory SPKs maven_PHASE_rec_YYMMDD_yymmdd_vV.bsp where PHASE is the mission phase: cru for cruise and MOI orb for all orbital phases YYMMDD is the file coverage start date yymmdd is the file coverage stop date V is the version; the file with the latest version supersedes all similarly named files with earlier versions. - structures SPKs maven_struct_vVV.bsp 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 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 all MAVEN instruments except MAG and LPW, for which common instrument geometric parameters normally stored in IKs are not applicable, and for the MAVEN antennae. These IKs were created by MAVEN instrument teams with help from NAIF. The IK files are provided under the spice_kernels/ik directory and are named according to the following scheme: - instrument and antennae IK files maven_NAME_vVV.ti where NAME is the instrument acronym ant (for antennae) euv iuvs ngims sep static swea swia VV is the version; the file with the latest version supersedes all similarly named files with earlier versions, but the SPICE user 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 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 orientation CKs These CKs created by NAIF contain the reconstructed MAVEN spacecraft attitude determined on-board and downlinked in spacecraft telemetry. - predicted spacecraft orientation CKs These CKs created by NAIF contain the predicted MAVEN spacecraft attitude and angular velocities from the Attitude Articulation Prediction/Simulation (AtArPS) Data Return Files (DRF) produced by the Spacecraft Team, LMCO. - reconstructed post-deploy Articulating Payload Platform (APP) orientation CKs These CKs created by NAIF contain the reconstructed MAVEN APP attitude computed from APP gimbal angles measured on-board and downlinked in spacecraft telemetry. - predicted post-deploy Articulating Payload Platform (APP) orientation CKs These CKs created by NAIF contain the predicted MAVEN APP gimbal rotations and rates from the AtArPS DRF files produced by the Spacecraft Team, LMCO. - reconstructed pre-deploy APP orientation CKs These CKs created by NAIF contain the reconstructed MAVEN APP attitude computed from pre APP deployment IUVS alignment calibration performed during cruise by the IUVS team, CU/LASP. - reconstructed IUVS mirror orientation CKs These CKs created by the IUVS team, CU/LASP contain the reconstructed MAVEN IUVS mirror orientation computed from from IUVS mirror angles measured on-board and downlinked in the IUVS housekeeping telemetry. - nominal SWEA orientation CK These CKs created by NAIF contain the nominal fixed SWEA orientation for pre- and post- SWEA boom deploy periods. The CK files are provided under the spice_kernels/ck directory and are named according to the following scheme: - all CKs mvn_NAME_TYPE_YYMMDD_yymmdd_vVV.bc where NAME is the structure acronym sc for spacecraft app for APP iuvs for IUVS swea for SWEA TYPE is the data type rel for reconstructed rem for reconstructed, merged pred for predicted prm for predicted, merged nom for nominal YYMMDD is the file coverage start date yymmdd is the file coverage stop date 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 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 0011 contains leap second data up to and including the July 1, 2015 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 correlation data for the main MAVEN on-board clock, created by NAIF from the SCLK_SCET files generated by the Spacecraft Team, LMCO. The SCLK files are provided under the spice_kernels/sclk directory and are named according to the following scheme: - main MAVEN spacecraft clock SCLK files mvn_sclkscet_VVVVV.tsc where VVVVV 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 MAVEN spacecraft, 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: - MAVEN mission FK files maven_vVV.tf where VV is the version; the file with the latest version supersedes all similarly named files with earlier versions, although a SPICE user might decide decide to use an earlier version if trying to be consistent with some earlier computed results. 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. The text MK files are provided under the spice_kernels/mk directory and are named according to the following scheme: - MAVEN yearly MK files maven_YYYY_vVV.tm when YYYY is the year covered by the kernels listed in the MK VV is the version; the file with the latest version supersedes all similarly named files with earlier versions. Multiple versions of a meta-kernel for the same year may exist if new kernels were added to the archive in a later release and the meta-kernel for that year had to be updated to incorporate them. The reasons for adding new kernels include (but are not limited to) adding new kinds of kernels, adding new versions of existing kernels containing more complete or more accurate data, and adding new versions of existing kernels superseding the existing kernels that had errors. If more than one meta-kernel file for the same year is present, then the file with the latest version number supersedes all earlier versions. The latest yearly meta-kernels can be loaded together sorted by year to provide coverage for more than one year. (Note that on some environments loading too many kernels at once may slow down data access.) 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, SCLK, IK, FK, generic SPKs, fixed offset SPKs, and fixed orientation CKs were included - the latest reconstructed MAVEN NAV SPKs were included - the adequate latest predicted CKs were included - the latest reconstructed CKs were 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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File Formats ============ All text documents 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, and FKs -- are UNIX text files, with a line feed character (ASCII 10) at the end of the line, and binary kernels 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: http://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: http://naif.jpl.nasa.gov specifically: Toolkit: http://naif.jpl.nasa.gov/naif/toolkit.html Utilities: http://naif.jpl.nasa.gov/naif/utilities.html Tutorials: http://naif.jpl.nasa.gov/naif/tutorials.html Lessons: http://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: http://naif.jpl.nasa.gov

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

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