The Hayabusa2 SPICE Data Archive
=======================================================================

  Last update: March 11, 2025


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

   This document describes the Hayabusa2 SPICE archive, containing
   observation geometry and other ancillary data in the form of SPICE
   System kernel files for the Hayabusa2 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
      DSK Files
      MK Files
   File Formats
   Reference
   Contact


Overview
========

   This archive includes the complete set of Hayabusa2 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 Hayabusa2 launch, 2014-12-03,
   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. 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. No Medium-Gain Antenna (MGA) CK is included. MGA CK may be added in a future release. 3. No Ion Engine System (IES) CK is included. IES CK may be added in a future release. 4. No Hayabusa2 spacecraft orientation kernels and trajectory kernels containing data during the six degrees of freedom control mode are included. 5. When loaded together, predicted, "hkattrpt" and "aocsc" spacecraft CKs provide continuous coverage except for three small gaps in 2018 and 2019 corresponding to the periods of the six degrees of freedom control mode: 2018-10-25T02:33:19.988 2018-10-25T02:47:24.008 2019-02-21T22:10:52.994 2019-02-21T22:26:30.013 2019-07-11T00:48:28.012 2019-07-11T01:03:55.003 6. Hayabusa2 ephemerides determined as by-product of shape model have many know gaps in SPK coverage because the trajectories were obtained from images. Intervals of taking the images are the source of the gaps. 7. Hayabusa2 NIRS3 MK File hyb2_nirs3_v01.tm has known gaps in SPK coverage. This file is provided to reproduce past computations done by the NIRS3 team. 8. Some Ryugu Shape models (DSKs) have duplicate vertices leading to non-zero Euler criterion value. 9. Hayabusa2 spacecraft orientation kernels, hyb2_aocsc_????_v02.bc, hyb2_hk_????_v02.bc, and hyb2_hkattrpt_????_v02.bc were generated with 1 day interpolation interval which are kept in the archive for historical purpose. They provide grossly incorrect interpolated results for many preriods due to their large interpolation interval. Their later version (v04) are recommended to users. 10. Hayabusa2 spacecraft orientation kernels obtained as a by-product of the production of shape models created with the SPC (Stereophotoclinometry) method or the SfM (Structure from Motion) method, hyb2_spc_20180619_20191119_v20200323.bc and hyb2_sfm_20180627_20191109_v20200815.bc, were generated with complete interpolation which are kept in the archive for historical purpose. They provide correct attitude only at the times of images used in shape production and produce grossly incorrect results at other times due to complete interpolation. The later version v03 is recommended to users, where SPC CK v03 is included in the archive and SfM CK v03 will be available in the archive in a future release. 11. Hayabusa2 "hkattrpt" spacecraft orientation kernels version v04, hyb2_hkattrpt_????_v04.bc, have ~1024 second interpolation interval which is occasionally incorrect orientation. 12. Hayabusa2 spacecraft trajectory kernels obtained as a by-product of the production of shape models created with the SPC (Stereophotoclinometry) method or the SfM (Structure from Motion) method, hyb2_spc_pos_20180619_20191119_v20200323.bsp and hyb2_sfm_pos_20180627_20191109_v20200815.bsp were generated with complete interpolation for each day which are kept in the archive for historical purpose. They provide correct trajectory only at the times of images used in shape production and produce grossly incorrect results at other times due to very long interpolation period. It is recommended to users that using these SPKs to compute data only at exact times of the images used in the SPC processing or the SfM processing. The later version of the SPK, v02 or later, is provided in this release for SPC and will be provided in a future release for SfM. 13. There are two SPKs for the asteroid proximity phase with many known gaps from 2018-06-03 07:08 to 2019-09-12 00:00, and there are no SPKs with better coverages. These many gaps severely reduce usability with SPICE APIs, such as the SPICE Geometry Finder subsystem routines. Hayabusa2 ephemeris to keep home position for the Asteroid Proximity phase, hyb2_hpk_20180627_20191119_v01.bsp, has many known gaps in SPK coverage because it doesn't contain the decent operations. Hayabusa2 ephemeris determined by LIDAR team, lidar_derived_trj_20191114_no6dofc_v03.bsp, has many known gaps because the trajectories were obtained from LIDAR data which have many gaps in SPK coverage.

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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] | |- readme.txt Bundle top-level readme file. | |-[spice_kernels] Directory containing SPICE kernels. | | | |-[ck] Directory containing CK files. | | | | | |-- *.bc Binary CK files. | | |-- *.xml PDS4 labels for CK files. | | | |-[dsk] Directory containing DSK files. | | | | | |-- *.bds Binary DSK files. | | |-- *.xml PDS4 labels for DSK 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 document collection. | |- 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 leap seconds 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. DSK (Digital Shape Kernel) files contain detailed shape models for extended objects such as planets, natural satellites, asteroids, and comet nuclei. DSK files are located under the spice_kernels/dsk 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.

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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 originally named DEXXX, JUPXXX, or MARXXX, e.g. DE430, JUP329, or MAR097. The original file coverages were shortened to reduce the file size and the original file names were renamed. - asteroid (162173) Ryugu ephemeris SPKs These SPKs contain ephemeris data for the asteroid (162173) Ryugu. Two files are produced by JPL and were retrieved from JPL Horizons On-Line Ephemeris System. The others are produced by ISAS/JAXA. - reconstructed spacecraft trajectory SPKs These SPKs contain final ephemeris data for the Hayabusa2 spacecraft based on the precise after-the-fact orbit determination solutions. - Hayabusa2 ephemeris for the Transfer phase and the Return phase These SPKs contain intermediate version of ephemeris data for the Hayabusa2 spacecraft. - Hayabusa2 ephemeris for the Approach phase These SPKs contain ephemeris data for the Hayabusa2 spacecraft based on the precise after-the-fact orbit determination solutions. - Hayabusa2 ephemeris to keep home position for the Asteroid Proximity phase These SPKs contain the predicted ephemeris for Hayabusa2 spacecraft for the asteroid proximity phase. This is the output of estimation tool: HPNAV to perform home position keeping operations. - Hayabusa2 ephemeris generated by OP-NAV These SPKs include the reconstructed ephemeris for Hayabusa2 determined by the JAXA/ISAS orbit group using OP-NAV for the TM-ORB operation period and the MNV-ORB operation period. - Hayabusa2 ephemeris determined by LIDAR team These SPKs contain ephemeris data for the Hayabusa2 spacecraft determined by the Hayabusa2 LIDAR team. - Hayabusa2 ephemeris determined as by-product of shape model These SPKs contain ephemeris data for the Hayabusa2 spacecraft determined as by-product of shape model by the Hayabusa2 Shape model team. - Hayabusa2 spacecraft structures positions This SPK includes the Hayabusa2 spacecraft structures positions relative to the origin of the spacecraft frame. - Hayabusa2 MASCOT instrument positions This SPK includes the instrument positions of the Hayabusa2 MASCOT lander relative to the center of mass of the MASCOT lander. - Hayabusa2 MASCOT landing site position This SPK includes the landing site positions of the Hayabusa2 MASCOT lander. - Hayabusa2 MASCOT ephemeris These SPKs contain ephemeris data for the MASCOT lander based on the after-the-fact trajectory determination. This archive includes binary SPK files under the spice_kernels/spk directory and are named according to the following scheme: - planetary ephemeris SPKs hyb2_NAMEVVV.bsp hyb2_NAMEVV1_NAME_VV2.bsp where NAME is type of file, de for JPL Development Ephemeris, jup for jupiter system, and mar for mars system VVV is the ephemeris version VV1 is the ephemeris version for the first part of the combined SPK VV2 is the ephemeris version for the second part of the combined SPK - asteroid (162173) Ryugu ephemeris SPKs by JPL 2162173_ryugu_vVV.bsp where VV is the version; the file with the latest version supersedes all similarly named files with earlier versions. - asteroid (162173) Ryugu ephemeris SPKs by ISAS/JAXA 2162173_ryugu_YYYYMMDD-yyyymmdd_NNNN_VVVVVVVV.bsp where YYYYMMDD is the file coverage start date yyyymmdd is the file coverage stop date NNNN is 0060 V is the version; the file with the latest version supersedes all similarly named files with earlier versions. - asteroid (162173) Ryugu ephemeris SPKs for the Approach phase by ISAS/JAXA 2162173_ryugu_approach_od_vVV.bsp where VV is the version; the file with the latest version supersedes all similarly named files with earlier versions. - asteroid (162173) Ryugu ephemeris SPKs for the Asteroid Proximity phase by ISAS/JAXA 2162173_ryugu_hpk_proximity_vVV.bsp where VV is the version; the file with the latest version supersedes all similarly named files with earlier versions. - reconstructed spacecraft trajectory SPKs hyb2_YYYYMMDD-yyyymmdd_IIIII_final_verV.bsp where YYYYMMDD is the file coverage start date yyyymmdd is the file coverage stop date IIIII is the time interval 0001m ... 1-minute interval 0001h ... 1-hour interval V is the version; the file with the latest version supersedes all similarly named files with earlier versions. - Hayabusa2 ephemeris for the Approach phase hyb2_approach_od_vyyyymmddhhmmss.bsp where yyyymmddhhmmss is the creation datetime. - Hayabusa2 ephemeris for the Transfer phase or the Return phase hyb2_asteroid_to_earth_YYYYMMDD_vVV.bsp hyb2_earth_to_asteroid_YYYYMMDD.bsp where YYYYMMDD is the creation datetime. VV is the version; the file with the latest version supersedes all similarly named files with earlier versions. - Hayabusa2 ephemeris to keep home position for the Asteroid Proximity phase hyb2_hpk_YYYYMMDD_yyyymmdd_vVV.bsp where YYYYMMDD is the file coverage start date yyyymmdd is the file coverage stop date VV is the version; the file with the latest version supersedes all similarly named files with earlier versions. - Hayabusa2 ephemeris generated by OP-NAV hyb2_opnav_YYYYMMDD_yyyymmdd_vVV.bsp where YYYYMMDD is the file coverage start date yyyymmdd is the file coverage stop date VV is the version; the file with the latest version supersedes all similarly named files with earlier versions. - Hayabusa2 ephemeris determined by LIDAR team lidar_derived_trj_XXXXXXXX_no6dofc_vVV.bsp where XXXXXXXX is the file creation date - Hayabusa2 ephemeris determined as by-product of shape model hyb2_TTT_pos_YYYYMMDD_yyyymmdd_vVVVVVVVV.bsp hyb2_TTT_pos_YYYYMMDD_yyyymmdd_vVVVVVVVV_vVV.bsp where TTT is the name of the method; spc or sfm YYYYMMDD is the file coverage start date yyyymmdd is the file coverage stop date VVVVVVVV is the version of the shape model which is the release date to the Hayabusa2 team in the YYYYMMDD format. VV is the version; the file with the latest version supersedes all similarly named files with earlier versions. ``_vVV'' can be omitted for the version 1. - Hayabusa2 spacecraft structures positions hyb2_struct_vVV.bsp where VV is the version; the file with the latest version supersedes all similarly named files with earlier versions. - Hayabusa2 MASCOT instrument positions hyb2_mascot_instruments_vVV.bsp where VV is the version; the file with the latest version supersedes all similarly named files with earlier versions. - Hayabusa2 MASCOT landing site position hyb2_mascot_ls_vVV.bsp where VV is the version; the file with the latest version supersedes all similarly named files with earlier versions. - Hayabusa2 MASCOT ephemeris hyb2_mascot_lander_vVV.bsp where VV is the version; the file with the latest version supersedes all similarly named files with earlier versions. Hayabusa2 spacecraft trajectory kernels obtained as a by-product of the production of shape models created with the SPC (Stereophotoclinometry) method or the SfM (Structure from Motion) method, hyb2_spc_pos_20180619_20191119_v20200323.bsp and hyb2_sfm_pos_20180627_20191109_v20200815.bsp were generated with complete interpolation for each day which are kept in the archive for historical purpose. They provide correct trajectory only at the times of images used in shape production and produce grossly incorrect results at other times due to very long interpolation period. It is recommended to users that using these SPKs to compute data only at exact times of the images used in the SPC processing or the SfM processing. The later version of the SPK, v02 is provided in this release for SPC and will be provided in a future release for SfM. There are many kinds of Ryugu SPKs. The most high quality trajectory during the asteroid proximity phase is provided by the Ryugu ephemeris SPKs, 2162173_ryugu_YYYYMMDD-yyyymmdd_NNNN_VVVVVVVV.bsp. For the approach phase, Ryugu ephemeris SPKs for the Approach phase, 2162173_ryugu_approach_od_vVV.bsp will provide the best trajectory. For the other period, use the SPK by JPL Horizons, 2162173_ryugu_vVV.bsp. These SPKs have overlaps, so it's recommended to users for a priority from highest to the lowest order, the asteroid proximity phase SPK, the approach phase SPK, and then the JPL Horizons SPK. There are many kinds of Hayabusa2 spacecraft SPKs. For any time, if there is reconstructed spacecraft trajectory SPK, hyb2_YYYYMMDD-yyyymmdd_IIIII_final_verV.bsp, it provides best quality trajectory. If there are both of 1-minute interval data with 0001m for IIIII in the filename and 1-hour interval data with 0001h for IIIII in the filename, 1-minute interval data is better. Note that these SPKs mask Hayabusa2 ephemeris for the Approach phase, hyb2_approach_od_vyyyymmddhhmmss.bsp for most of the time. For the asteroid proximity phase, Hayabusa2 ephemeris determined by LIDAR team which was derived from LIDAR data and HPK (Home Position Keeping) trajectory, lidar_derived_trj_XXXXXXXX_no6dofc_vVV.bsp, will provide higher quality trajectory than others. If one wants to compute data at exact times of the images used in the SPC processing or the SfM processing, Hayabusa2 ephemeris determined as by-product of shape model, hyb2_TTT_pos_YYYYMMDD_yyyymmdd_vVVVVVVVV_vVV.bsp, might give best trajectory than others including trajectory using LIDAR data. From 2019-09-12 to 2019-09-21 and from 2019-10-01 to 2019-10-07, Hayabusa2 ephemeris generated by OP-NAV (Optical Navigation), hyb2_opnav_YYYYMMDD_yyyymmdd_vVV.bsp, are available and will give better trajectory. For the other periods during the asteroid proximity phase, Hayabusa2 ephemeris to keep home position for the Asteroid Proximity phase, also called as HPK trajectory, hyb2_hpk_YYYYMMDD_yyyymmdd_vVV.bsp, gives Hayabusa2 trajectory obtained as a result of Home Position Keeping operation.

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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, and asteroid Ryugu text PCK files produced by the Hayabusa2 shape model team and the Hayabusa2 data archive team. The generic text PCK version 00010 contains data from the 2009 report, and the generic text PCK version 00011 contains data from the 2015 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 their analysis task. - asteroid Ryugu text PCK files ryugu_vVV.tpc where VV 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 their 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 (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 Hayabusa2 scientific instruments. These IKs were created by Hayabusa2 instrument teams. The IK files are provided under the spice_kernels/ik directory and are named according to the following scheme: - instrument IK files hyb2_NAME_vVV.ti where NAME is the instrument abbreviation lidar nirs3 onc tir mascot_cam mascot_mag mascot_mara 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 their 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: - Hayabusa2 spacecraft yearly CKs based on House Keeping telemetry These CKs created by ISAS/JAXA contain the Hayabusa2 spacecraft attitude determined on-board and downlinked in spacecraft house keeping telemetry. There are no CKs for 2018 or later because the Hayabusa2 spacecraft yearly CKs based on House Keeping telemetry and attitude report packet are provided. - Hayabusa2 spacecraft yearly CKs based on House Keeping telemetry and attitude report packet These CKs created by ISAS/JAXA contain the Hayabusa2 spacecraft attitude determined on-board and downlinked in spacecraft house keeping telemetry and attitude report packet. The attitude report packet is used when the downlink rate is not enough to send house keeping packets. The attitude precision is the same as that in house keeping telemetry. These CKs are less accurate than the AOCSC CKs in terms of not just less precision in source data but also in terms of less reliable interpolation. - Hayabusa2 spacecraft yearly CKs based on AOCSC telemetry These CKs created by ISAS/JAXA contain the Hayabusa2 spacecraft attitude determined on-board and downlinked in spacecraft AOCSC telemetry. The AOCSC telemetry contains larger number of digits than HK telemetry for the spacecraft orientation, while the time coverage of the AOCSC is limited due to the bandwidth. - Hayabusa2 spacecraft CKs determined as by-product of shape model These CKs contain orientation data for the Hayabusa2 spacecraft determined as by-product of shape model by the Hayabusa2 Shape model team. - Hayabusa2 spacecraft yearly predicted CKs These CKs created by ISAS/JAXA contain the Hayabusa2 spacecraft attitude created from the command history to fill gaps of the time coverage in the other CKs. - Hayabusa2 spacecraft nominal orientation CK This CK created by ISAS/JAXA contain the nominal attitude of the Hayabusa2 spacecraft for the asteroid proximity phase. - Hayabusa2 MASCOT lander CKs These CKs created by DLR contain the MASCOT lander attitude determined by analyzing images from the camera onboard Mascot. This archive includes binary CK files under the spice_kernels/ck directory and are named according to the following scheme: - Hayabusa2 spacecraft yearly CKs based on House Keeping telemetry hyb2_hk_YYYY_vVV.bc where YYYY is the year covered by the CK kernel VV is the version; the file with the latest version supersedes all similarly named files with earlier versions. - Hayabusa2 spacecraft yearly "hkattrpt" CKs based on House Keeping telemetry and attitude report packet hyb2_hkattrpt_YYYY_vVV.bc where YYYY is the year covered by the CK kernel VV is the version; the file with the latest version supersedes all similarly named files with earlier versions. - Hayabusa2 spacecraft yearly "aocsc" CKs based on AOCSC telemetry hyb2_aocsc_YYYY_vVV.bc where YYYY is the year covered by the CK kernel VV is the version; the file with the latest version supersedes all similarly named files with earlier versions. - Hayabusa2 spacecraft yearly predicted CKs hyb2_YYYY_pred_vVV.bc where YYYY is the year covered by the CK kernel VV is the version; the file with the latest version supersedes all similarly named files with earlier versions. - Hayabusa2 spacecraft CKs determined as by-product of shape model hyb2_TTT_YYYYMMDD_yyyymmdd_vVVVVVVVV.bsp hyb2_TTT_YYYYMMDD_yyyymmdd_vVVVVVVVV_vVV.bsp where TTT is the name of the method; spc or sfm YYYYMMDD is the file coverage start date yyyymmdd is the file coverage stop date VVVVVVVV is the version of the shape model VV is the version; the file with the latest version supersedes all similarly named files with earlier versions. If no version variable VV in the filename, it means that VV is 01. - Hayabusa2 MASCOT lander CKs hyb2_mascot_lander_vVV.bc where VV is the version; the file with the latest version supersedes all similarly named files with earlier versions.

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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 correlation data for the main Hayabusa2 on-board clock, created by the Hayabusa2 Data Archive team from the time calibration table generated by C-SODA, ISAS/JAXA. The SCLK files are provided under the spice_kernels/sclk directory and are named according to the following scheme: - main Hayabusa2 spacecraft clock SCLK files hyb_yyyymmdd_vVV.tsc where yyyymmdd 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 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 Hayabusa2 spacecraft, its structures, and science instruments. These FKs were produced by the Hayabusa2 Data Archive team 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: - Hayabusa2 mission FK files hyb2_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 to use an earlier version if trying to be consistent with some earlier computed results. - Hayabusa2 additional mission FK files hyb2_hp_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 to use an earlier version if trying to be consistent with some earlier computed results. - Ryugu FK files hyb2_ryugu_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 to use an earlier version if trying to be consistent with some earlier computed results. - Hayabusa2 DSK surface name/ID mapping FK files hyb2_shape_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 to use an earlier version if trying to be consistent with some earlier computed results. - Hayabusa2 MASCOT FK files hyb2_mascot_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 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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DSK Files DSK (Digital Shape Kernel) files contain detailed shape models for extended objects such as planets, natural satellites, asteroids, and comet nuclei. This archive includes binary DSK files containing digital shape data for the Hayabusa2 mission target asteroid (162173) Ryugu. These DSKs were produced by the Hayabusa2 Shape Model team. The DSK files are provided under the spice_kernels/dsk directory and are named according to the following scheme: - asteroid (162173) Ryugu DSK files ryugu_shape_SSS_RRRR_vVVVVVVVV.bds where SSS is the shape model source: spc Stereo-photoclinometry sfm Structure-from-Motion RRRR is the number of plates; 49k, 50k, 200k, 800k, or 3m VVVVVVVV is the version number The most detailed description of the data in each DSK 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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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. This archive includes following types of MK files: - Hayabusa2 yearly MK files These MKs contain the data for year specified in the filename. - Hayabusa2 NIRS3 MK Files These MKs contain the data for calculating geometry for NIRS3 data which was used for creating data in the NIRS3 bundle. These MKs doesn't contain any CK files and are intended for calculation of distance between target and the spacecraft. - Hayabusa2 ONC MK Files There are two types of MK file, one is the Hayabusa2 ONC LIDAR MK File, and the other is the Hayabusa2 ONC SPC MK File. The Hayabusa2 ONC LIDAR MK File contains the kernels for calculating geometry for ONC data using LIDAR SPK. The Hayabusa2 ONC SPC MK File contains the kernels for calculating geometry for ONC data using SPC-derived SPK and CK. For some cases, SPC-derived SPK and LIDAR derived SPK significantly differ, so there are two types of MK to switch the other MK to easily examine which MK is better. These MKs were used for creating data in the ONC bundle. - Hayabusa2 LIDAR MK Files These MKs contain the kernels for the processing of LIDAR Level 3 and Level 4 data products for Ryugu. The text MK files are provided under the spice_kernels/mk directory and are named according to the following scheme: - Hayabusa2 yearly MK files hyb2_YYYY_vVV.tm when YYYY is the year covered by MK VV is the version; the file with the latest version supersedes all similarly named files with earlier versions. - Hayabusa2 NIRS3 MK files hyb2_nirs3_vVV.tm when VV is the version; the file with the latest version supersedes all similarly named files with earlier versions. - Hayabusa2 ONC MK files hyb2_onc_TTT_vVV.tm when TTT is the kind of kernel set; lidar or spc. VV is the version; the file with the latest version supersedes all similarly named files with earlier versions. - Hayabusa2 LIDAR MK files hyb2_lidar_vVV.tm when VV is the version; the file with the latest version supersedes all similarly named files with earlier versions. Multiple versions of a meta-kernel may exist if new kernels were added to the archive in a later release and the meta-kernel 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 is present, then the file with the latest version number supersedes all earlier versions. (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 Ryugu SPKs were included - the latest reconstructed Hayabusa2 NAV SPKs were included - the latest predicted CKs were included - the latest reconstructed "hkattrpt" CKs were included - the latest reconstructed "aocsc" CKs were included - latest global DSK with 800K plates was included Note that the hkattrpt CKs are less accurate than aocsc in terms of not just less precision in source data but also in terms of less reliable interpolation. 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. Following MKs are included in the archive for the record: - Hayabusa2 yearly MK files - hyb2_2014_v01.tm - hyb2_2015_v01.tm - hyb2_2016_v01.tm - hyb2_2017_v01.tm - hyb2_2018_v01.tm - hyb2_2019_v01.tm - hyb2_2020_v01.tm - Hayabusa2 NIRS3 MK file - hyb2_nirs3_v01.tm - Hayabusa2 ONC MK files - hyb2_onc_lidar_v01.tm - hyb2_onc_spc_v01.tm The users are recommended to not use these MKs, and use their later versions if provided, except for reproducing past results made with these MKs.

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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: - Hayabusa2 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 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 -- and the checksum files are UNIX text files, with a line feed character (ASCII 10) at the end of each line. Binary kernels files -- SPKs, CKs, and DSKs -- 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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Reference ========= For more information about the SPICE system, see documentation and tutorials available at the NAIF Node of the PDS: https://naif.jpl.nasa.gov

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Contact ======= Hayabusa2 Data Archive Team Japan Aerospace Exploration Agency Institute of Space and Astronautical Science 3-1-1 Yoshinodai, Chuo, Sagamihara, Kanagawa, 252-5210 JAPAN email: darts-admin@ML.isas.jaxa.jp

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