ACIS Instrument Support - Monthly Progress Report for May 2020

1.  ACIS Characterization

1.3 Monitor scientific on-orbit performance of ACIS

  ...  Following Chandra entry into safe mode on May 24, verified ACIS was safe, monitored housekeeping data during recovery, and support safe mode recovery.  Ran two CAPs to collect an additional 100 ksec of ACIS calibration source data during the shutdown including a substantial fraction at a cold focal plane temperature.  All ACIS team members successfully supported safe mode recovery remotely.

  ...  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).

  ...  Received and set up new laptop and associated equipment to replace failing laptop used to support ACIS operations and instrument monitoring.

  ...  Submitted request for more raw mode ECS data.

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 MAY0420A load.   Will continue to run monthly.  MIT telemetry processing will automatically check the results and send out an alert if the checksum is unexpected.

  ...  The ACIS Engineering Unit remains powered off, which is the safest long-term unsupervised state.  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.

  ...  Updating documentation of ACIS data flow through the FEPs, the BEP, and various on-board telemetry buffers.

2.3 Instrument science performance

  ...  Participated in monthly ACIS operations meetings.  Discussed ACIS response to the recent safe mode, and proposed changes to the default ACIS safing configuration.

  ...  Participated in SOT radiation working group telecon.

  ...  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 inputs to discussions between observers and user support.

  ...  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

  ...  Participated in CXC Cal/Ops ACIS response discussion group.  Discussed ECS statistics,  allowing higher focal plane temperatures for some classes of observations, and contamination.

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


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.  Improvement to remote operation configuration which automatically logs in and starts the VNC server after log off.

  ...  Reported on ACIS telemetry logs and telemetry gaps at the OCC to ground operations team.

4.2 Generation of commands for ACIS observations

  ...  Reviewed high count rate Chandra cycle 22 proposals for potential health and safety issues.

  ...  Updating and improving a database of ACIS command load files.

  ...  Continued working on contingency plans for how to update the ACIS ruleset and ACIS tables in the event of a FEP failure.

  ...  Reviewed an internal ACIS summary of safe mode indicators and response.

  ...  Reviewed MAY1820A command load.  Reviewed MAY2420 and JUN0120 LTS OR lists, MAY2520 preliminary schedule, and MAY1820 final OR list.

  ...  Assigned 10 SI modes. Dropped chips from 3 ObsIDs.

  ...  Checking on automated processes associated with SACGS.