Hera SPK files
===========================================================================

   This ``aareadme.txt'' file describes the contents of the kernels/spk
   directory of the Hera SPICE Kernel Dataset.

   It was last modified on April 26, 2024 by Alfredo Escalante, ESAC/ESA.


Brief Summary
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   This directory contains the SPICE SP-Kernel files for the Hera
   mission, including mission analysis, nominal and operational spacecraft
   trajectory SPKs, generic planetary and satellite ephemeris SPKs.


File naming conventions
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   Naming Scheme for Hera mission SPKs:

     The naming scheme for the Hera spacecraft and its cubesats SPKs is:

           hera_SC_TYPE[_ID][_DESC]_YYYYMMDD_YYYYMMDD_vNN.bsp

     where

           SC        acronym of the spacecraft:

                          hera:     for Hera;
                          milani:   for Milani cubesat;
                          juventas: for Juventas cubesat

           TYPE      Data type, where a reference to the originator of the
                     data, the type of data and the and the reference period
                     is provided. This is a three letter acronym. The first
                     letter defines the file originator:

                          s: Science Operations Center;
                          m: Mission Analysis;
                          f: Flight Dynamics;

                     the second letter defines the reference period of the
                     data:

                          c: Cruise phase;
                          l: Science phase Long term;
                          m: Science phase Medium term;
                          s: Science phase Short term;
                          o: Undefined;

                     the third letter indicates the type of data

                          p: Predicted data;
                          r: Reconstructed data;
                          t: Test data;

           ID        mapping to the original file product IDs as defined
                     per an ICD document (optional);

           DESC      description of the original reference file of any
                     particular of the original file (optional);

           YYYYMMDD  coverage start and stop times in TDB (required);

           NN        version number, starting from 01 (required; e.g. 01);


Current SPK Kernels Set
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   hera_sc_crema_2_0_DESCR.bsp

      SPICE SPK file that contains Hera spacecraft CReMA 2.0 trajectories
      covering from launch to arrival to Didymos for the following scenario.
      Where DESCR:

      LPO: Launch Period Open.

      LPC: Launch Period Close.

      ECP: Early Characterization Phase.

      PDP: Payload Deployment Phase.


   hera_sc_PO_DESCR.bsp

      SPICE SPK file that contains Hera spacecraft trajectory covering from
      launch to arrival to Didymos for the following scenario. Where DESCR:

      LPC_EMA_2024c:   LPO and LPC of 2024 Earth-Mars-Didymos transfer with
                       constraints on departure Vinf <= 5.1 km/s and arrival
                       no later than 2026/12/28. Launch period has been
                       shortened to 18 days in order to keep total
                       Delta-V < 1100 m/s.

      LPC_EEA_2025a64: LPO and LPC of 2025 Earth-Earth-Didymos transfer with
                       constraints on departure Vinf <= 6.0 km/s, departure
                       declination fixed to 18 deg and arrival no later than
                       2031/01/31. a64 stands for Arianne 64.

      LPO_EA_2026a64:  LPO and LPC of 2026 Earth-Didymos transfer with
                       constraints on departure Vinf <= 6.0 km/s and
                       arrival no later than 2031/01/31. a64 stands for
                       Arianne 64.

      PO:              Proximity Operations based on the trajectories reported
                       on RD27.

      Created by the GMV.


   de432s.bsp

      SPICE SPK file containing JPL planetary ephemerides version DE432,
      created by NAIF, JPL.


   mar097_YYYYMMDD_YYYYMMDD.bsp

      SPICE SPK file containing JPL Martian satellite ephemerides version
      MAR097. Created by NAIF, JPL.


   estrack_vNN.bsp

      SPICE SPK file that defines the position for each of the ESA ESTRACK
      ground stations, as seen from the center of the Earth, in the
      topocentric frame defined in the corresponding ESTRACK FK. Created by
      the ESA SPICE Service (ESS).


   hera_sci_vNN.bsp

      SPICE SPK file that defines the position of some relevant points
      for science purposes. Created by the ESA SPICE Service (ESS).


   hera_dart_impact_site_vNN.bsp

      SPICE SPK file that defines the position of the DART impact site
      from last DART reconstructed trajectory. Created by the ESA SPICE
      Service (ESS).


   hera_struct_vNN.bsp

      SPICE SPK file that contains Hera spacecraft structures positions that
      apply during all the mission. Created by the ESA SPICE Service (ESS).


Other directory contents
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   aareadme.txt         This file.

   coverage.txt         File that contains a summary of the coverage
                        of all the SPK files present in the directory.


Particulars
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   Trajectory data is consistent with planetary ephemeris DE-432 and with
   the leapseconds kernel naif0010.tls

   The detailed manoeuvre sequence for arrival to Didymos is not modelled
   in the provided orbit files. An operationally robust arrival sequence
   implies a delay of about 1-2 months of the arrival date.


Kernel File Details
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     The most detailed description of the data in a binary SPK file is
     provided in metadata included inside the comment area of the file.
     This information can be viewed using the utility programs COMMNT and
     SPACIT included in the NAIF Toolkit.


Contact Information
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     If you have any questions regarding this directory or its
     contents, please contact SPICE support at ESAC:

             Alfredo Escalante Lopez
             (+34) 91-8131-429
             spice@sciops.esa.int

     or NAIF at JPL:

             Boris Semenov
             (818) 354-8136
             Boris.Semenov@jpl.nasa.gov


References and required readings
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     1. ``SPK Required Reading'', NAIF Document


End of aareadme file.