BepiColombo MK files =========================================================================== This ``aareadme.txt'' file describes the contents of the kernels/mk directory of the BepiColombo SPICE Kernel Dataset. It was last modified on November 26, 2019 by Marc Costa Sitja, ESAC/ESA. Brief Summary -------------------------------------------------------- This directory contains the SPICE Meta-Kernel files for the BepiColombo mission. Meta-kernels (also known as ``FURNSH kernel'') are used to name a collection of kernels that are to be loaded into a user's application at run-time. Meta-kernels are appropriate to group kernels that correspond to a certain study group, phase or kernel state of the mission. File naming conventions -------------------------------------------------------- Naming Scheme for BepiColombo mission MKs: The naming scheme for the BepiColombo spacecraft MKs is: bc[_DESC][_vXXX][_TAG][_NNN].tm where DESC a brief description of the scope of study of the scenario (optional); vXXX version number that corresponds to the version of the meta-kernel or the SPICE Kernel Dataset release number (optional; e.g. v121 for Release 1.2.1) TAG a time tag of the MK generation time (optional; e.g. 20160928); NNN a count of the MK version generated for a given TAG (mandatory if TAG is included; e.g 001) Other directory contents -------------------------------------------------------- aareadme.txt This file. former_versions Directory where versions no longer valid are stored for archive purposes. Particulars -------------------------------------------------------- Meta-Kernel file management is a critical element of any SPICE dataset. For ESA Planetary Missions the Meta-Kernels of the operational SPICE repositories are also used to control the version of the SPICE dataset. In general missions in operations will have an ``operational'' meta-kernel (OPS) and a ``planning'' meta-kernel (PLAN). In general, for BepiColombo the OPS MK includes as-flown information and short-term attitude and trajectory files from Flight Dynamics whereas the PLAN MK includes predicted and test trajectory and orientation. More in detail: The OPS meta-kernel will contain: - Trajectory: Predicted and reconstructed from Flight Dynamics (FDy); the data is in the same file, typically includes reconstruction and a predicted segment) - Attitude: As-flown orientation data from the Housekeeping (HK_TM) Telemetry and predicted/commanded attitude from FDy. The FDy prediction will be overwritten by the HK_TM - Structures/Payload: As-flown orientation without a default default profile (there might be data gaps) The PLAN meta-kernel will contain: - Trajectory: Predicted and reconstructed from FDy plus the MOI and Science Phase trajectories from Mission Analysis and a test extended mission trajectory. - Attitude: Predicted/commanded attitude from FDy and test attitude for the Cruise phase, MOI and science phase generated by the ESA SPICE Service. - Structures/Payload: Default profile (usage is not recommended). Since the periodicity of this updates ranges from hours to weeks, the MK in the Meta-Kernel directory does not have a version number and is regularly overwritten. Nevertheless in order to keep traceability and backwards compatibility with former MKs, a duplicate of every generated operational MK is stored. This duplicated MK filename is appended with a time tag and a version; if the original MK looks like: ftp/data/SPICE/BEPICOLOMBO/kernels/mk/bc_ops.tm the following duplicate is generated: ftp/data/SPICE/BEPICOLOMBO/kernels/mk/bc_ops_v230_20191128_001.tm Kernel File Details -------------------------------------------------------- Name Comments --------------------------------------------------------------------- bc_ops.tm Contains the latest available operational kernels generated by the SPICE operational pipeline. bc_ops_vXXX_YYYYMMDD_NNN.tm Is a duplicate of the operational MK that derived from release vXXX. If multiple operational MK files are generated on the same date the version NNN is increased starting from 001. Read the ``Particulars'' section for more information. bc_plan.tm Contains the long, mid and short term operational kernels generated by the SPICE operational pipeline. bc_plan_vXXX_YYYYMMDD_NNN.tm Is a duplicate of the planning MK that derived from release vXXX. If multiple operational MK files are generated on the same date the version NNN is increased starting from 001. Read the ``Particulars'' section for more information. Contact Information -------------------------------------------------------- If you have any questions regarding this file contact the ESA SPICE Service (ESS) at ESAC: Alfredo Escalante Lopez (+34) 91-8131-429 spice@sciops.esa.int References and required readings -------------------------------------------------------- 1. ``Kernel Required Reading'', NAIF Document End of aareadme file.