ACIS Instrument Support - Monthly Progress Report for March 2020

Commencing on March 13, MIT instituted mandatory work from home due to COVID-19.  Team is experienced with remotely supporting normal operations, instrument monitoring, and anomaly response.

1.  ACIS Characterization

1.3 Monitor scientific on-orbit performance of ACIS

  ...  Continued monitoring of ACIS CTI, gain, trailing pixel pulseheight, detector efficiency, corner pixel distribution, spectral line centroid and width, and focal plane temperature.  Updated monitoring web pages.  (http://space.mit.edu/~cgrant/monitor.html).

  ...  Making plans for creating additional ECS diagnostic SI modes that use fewer CCDs and could be desirable thermally.

  ...  Discussing alternate uses for format 1 time during HRC observations, including measuring board temperatures or raw pixel data from small regions.  Currently taking event histogram data during this time.

  ...  Began preparing materials for April Chandra Quarterly review.

2.  Engineering

2.1 Instrument hardware engineering performance

  ...  Continue to monitor long term ACIS instrument performance.  Reviewed trends in engineering data for the past 60 days; no unexpected trends were seen.

  ...  The EEPROM checksum was verified in the MAR0920A load.   Will continue to run monthly.  MIT telemetry processing will automatically check the results and send out an alert if the checksum is unexpected.

  ...  Executed a focal plane cooling test Mar 28.  Cooling curve looks unchanged.

  ...  After substantial discussion, determined the safest long-term unsupervised state for the ACIS Engineering Unit is to be powered off.  This imposes a moratorium on new SI modes for observers, testing new FSW patches, and testing anomaly scenarios until campus access is restored.   

2.2 Flight software maintenance

  ...  ACIS flight software patch G-H-I (improved buscrash and new deahktrip) uploaded on January 24, 2020.  First new patch set since June 2014.  No issues to date.

  ...  We continue to monitor threshold crossing rates.  The current TXINGS parameters were last updated on July 28, 2016.  Threshold crossing rates may have flattened out and started decreasing recently, potentially indicating the end of solar minimum.

  ...  Continued work on a major update to the ACIS FSW User's Guide review to edit/augment with clearer text and fill in missing sections, information, and caveats. Initial reviews from the project engineer.

  ...  Updating documentation of ACIS data flow through various on-board telemetry buffers.

  ...  Experimenting with what would be required to get the ACIS binaries to run under the QEMU processor emulator.

2.3 Instrument science performance

  ...  Participated in monthly ACIS operations meetings.  Discussed plan for potential COVID-19 work from home order, updates to EGSE at Wayside, checked that Zoom and Google Meet work for everybody.  Substantial discussion of anomaly response while working at home.

  ...  Continued daily quick-look processing of ACIS telemetry and maintained Web interface to ACIS real-time data.  

  ...  Continued to publish the "annotated DOT" timeline reports.


3.  CXC Support

3.1 Provide user support

  ...  Provided input and comments on ACIS article for upcoming Chandra newsletter.

  ...  ACIS memo listing calibration ObsIDs and observation characteristics (ACIS Memo #165) will no longer be updated.  Functionality is replaced by new web page (http://acis.mit.edu/asc/evt-page.html), which provides the same information but is more automated.

3.2 Provide data analysis support

  ...  Discussed with CXC Cal scientist how to diagnose problems with CTI-temperature correction.

  ...  Continued to maintain ACIS calibration database of ground and flight data products.

  ...  Participated in discussion of planned April IACHEC meeting, which was postponed to September. 


4.  OCC Support

4.1 Use of MIT/ACIS EGSE at OCC

  ...  Continued support and maintenance of ACIS EGSE software and hardware at the Wayside OCC. Improved access to the ACIS EGSE in the control room through VNC and screen sharing means anomaly response should not require in-person support at the OCC.

  ...  Completed the process of getting a Jira account at the OCC which allows more access to OCC displays and resources from home.

4.2 Generation of commands for ACIS observations

  ...  Supported discussion of contingency plans in case of extended DSN outages.  Reviewed CAP for "deadman" load which is now continually running and will safe the instruments if there is no commication after 48 hours.  Supported planning for a "lights out load", an extended command load which would balance thermal and momentum needs if there were a planned long-lasting DSN outage.

  ...  Reviewed CLD files for a grid of focal plane temperature set points and for the current optimal txings parameter file.  Approved by FDB for flight-use.

  ...  Continue working to assign SI modes for remaining observations in cycle 21.  Interacting with USINT to finalize configurations and correct chip drop order errors.  All planned observations in cycle 21 now have SI mode assignments.  Two untriggered TOOs have problematic chip drop configurations.

  ...  Answered USINT question on choice of aimpoint for maximum spectral resolution.

  ...  Worked with USINT on bad optional chip drop order.

  ...  Worked with proposer interested in previous ACIS configurations for observing the Crab.

  ...  Reviewed MAR1220A and MAR1620A command loads.  Reviewed MAR3020 LTS OR list, MAR1220 and MAR2320 preliminary schedules, and MAR1220 final OR list.

  ...  Dropped chips from 9 ObsIDs.

  ...  Checking on automated processes associated with SACGS.