Pysche Gamma Ray Spectrometer Release Notes 

This document, psyche_grs_release_notes.txt, contains release notes and 
errata concerning the Psyche Gamma Ray Spectrometer bundle. It is updated with 
each release of Psyche Gamma Ray Spectrometer data.

This document contains an entry for each Psyche Gamma Ray 
Spectrometer PDS Release with additional information about the contents of the release, 
in order from newest to oldest. Updates to previously released files are 
reported in these entries, along with any known errata.

******** RELEASE-SPECIFIC INFORMATION ********
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Release Number: 2
Delivery Date: 2025-08-15
New Data Coverage: 2025-04-01 through 2025-06-30
Updated Data Coverage: 2023-10-13 through 2025-03-31

New products added to these collections:
        urn:nasa:pds:psyche.grs:data_raw
        urn:nasa:pds:psyche.grs:document

Products revised in these collections:
	urn:nasa:pds:psyche.grs:data_raw
        Updated Product Observational labels (v1.1) for 2023-10-13 through 2025-03-31. 
        (see below)

        urn:nasa:pds:psyche.grs:document
        Updated SIS documentation (see below)

Purpose of delivery:
        Second data delivery from 2025 day of year 091 through 2025 day of year 181, and 
        redelivery of labels from Release 1. It was discovered that the subseconds values
        reported by the instrument were in subsecond ticks different from units expected 
        by the Psyche SPICE SCLK kernel. This required changes to the following:

        1. Updates to the SIS, Section 5.7.2, explaining the difference between the
        instrument subseconds ticks and that of the SPICE SCLK kernel. Also added a step
        to the conversion from SCLK to UTC times that involves converting the instrument
        subsecond values to units expected by SPICE. 

        2. Updates to the SIS for each of the data products under Section 6.2, 
        to explicitly state the subsecond ticks units for each subseconds field. 

        3. Updates to the GRS PDS labels, clarifying the subsecond ticks units for each
        subseconds field, and updating the start_date_time, stop_date_time values 
        using the updated SCLK to UTC conversion.

        4. Updates to the <version_id>, <Modification_History>, and <software_version_id>
        to reflect the updates in the data product labels and SIS documentation. 

        Note that the binary data files themselves are not regenerated as they only
        contain the raw data values reported by the instrument. There are no derived
        SPICE values in the data. 
        

Spacecraft activities during data coverage period:
        None  

Anomalies:
        Beginning on 2025-04-02 at 13:38:44 UTC, the Psyche spacecraft's Safe Mode was 
        triggered due to a thruster crossing the low pressure threshold. The spacecraft 
        remained in Safe Mode for 53.9 hours. Instrument activity was not affected by this
        safe mode event.  

Additional Comments:
        None 

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Release Number: 1
Delivery Date: 2025-05-28
Data Coverage 2023-10-13 through 2025-03-31

New products added to these collections:
        urn:nasa:pds:psyche.grs:data_raw
        urn:nasa:pds:psyche.grs:document

Products revised in these collections:
        None 

Purpose of delivery: 
        Initial data release from Launch on 2023-10-13 through 2025 day of year 090.

Spacecraft activities during data coverage period:
        Launch: 2023-10-13
        Instrument powered on: 2023-11-06
        Initial Checkout: 2023-10-13 through 2024-01-21 
        Periodic Maintenance and Calibration Roll 1: 2024-07-18 
        Periodic Maintenance and Calibration Roll 2: 2025-01-26 

Anomalies:
        During Periodic Maintenance & Calibration (PMC) #1, which ran from 
        July 15 - 18 2024, we performed a simulation of Psyche Orbital operations 
        (on July 17) which included disabling the raw HPGe spectra. During this time, 
        only the Anti-Coincidence (AC) HPGe spectra were produced. This accounts for the 
        lack of Ch0_Raw_Spec events reported by the GRS Raw Counters data product during
        this time. This is noted in the recently published Psyche GRNS calibration paper. 
        Note that the PMCs will frequently include activities that may result in 
        undocumented changes in the science products, as the team continues to perform 
        activities like that detailed here, as well as updates to pulse processing 
        parameters to optimize science performance prior to arrival at asteroid 16 Psyche.

Additional Comments:
        None 

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Users are encouraged to provide comments to the PDS Small Bodies Node
if errors are found either in data or in documentation in this archive.
Please send comments by e-mail to:

     PDS Small Bodies Node, Asteroid Subnode
     Planetary Science Institute
     Phone: (520) 622-6300
     Web:  https://sbn.psi.edu/pds/
     Email:  sbn@psi.edu