ACIS Instrument Support - Monthly Progress Report for February 2023

1.  ACIS Characterization

1.3 Monitor scientific on-orbit performance of ACIS

  ...  Following Chandra safe mode on Februrary 13, verified ACIS was safe, monitoring housekeeping data during recovery.  Ran CAP1698 to collect ECS data during recovery.  Resolved issue with SAO clock fencepost files after OBC switches during safing and recovery.

  ...  Due to high radiation environment, the ACIS team recommended a shutdown of science observing on February 27. 

  ...  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).

  ... Continued study of ACIS quiescent particle background time variability by expanding the dataset to include not just stowed ECS data, but also all science data taken with standard ACIS configurations.  

2.  Engineering

2.1 Instrument hardware engineering performance

  ...  Continue to monitor long term ACIS instrument performance.  Engineering trending over the past 60 days is nominal.

  ...  The EEPROM checksum was verified in the FEB0623A loads. Will continue to run monthly.  MIT telemetry processing will automatically check the results and send out an alert if the checksum is unexpected.

  ...  Continued weekly physical audit of the ACIS Engineering Unit lab.  Updates to instructions for command testing on the EU, in response to MKI network changes, are underway.

2.2 Flight software maintenance

  ...  Final version of the patch H-J-K ECO was reviewed, revalidated, and released and the patch load is ready for procedure development. This patch load includes three new standard patches and an update to an existing patch, which fix bugs and improves the ACIS response to unexpected shutdowns and BEP crashes. 

  ...  ACIS flight software patch G-I-J (improved TXings) uploaded on August 11, 2022.  First new patch set since January 2020.  No issues to date.

  ...  We continue to monitor threshold crossing rates. Threshold crossing rates are dropping and a new set of TXing parameters were uploaded on Feb 10, 2023. The previous parameter update was September 12, 2022.  Reviewed SAR for TXing parameter update.


2.3 Instrument science performance

  ...  Participated in monthly ACIS operations meeting.  Discussed recent safe mode, the new HEAD background check requirement, and Engineering Unit/MKI network status.

  ...  As required by new SAO rules, MIT ACIS team submitted fingerprints and forms for background checks.

  ...  Continued daily quick-look processing of ACIS telemetry and maintained Web interface to ACIS real-time data.  Created new documentation for previously undocumented EGSE scripts.

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


3.  CXC Support

3.1 Provide 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

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

  ...  Participated in CXC Cal/Ops response discussion group.  Discussed status of time-dependent gain correction, updates to the calibration of the CTI correction algorithm, and potential astronomical targets for high energy gain calibration.


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.  Restarted both EGSE machines routinely.


4.2 Generation of commands for ACIS observations

  ...  Continued training of MIT ACIS team member on ACIS ops on-duty tasks. Reviewed SI mode creation, specifically custom ECS modes, reviewed instructions for long ECS observations CAP creation, rehearsed load reviews, OR list reviews, and SI mode assignments.  Rehearsed real-time telemetry monitoring..

  ...  Updates to command generation procedures are underway, in response to changes to the MKI network and the interface to the ACIS EU.  Successful first test run.

  ...  Corresponded with CXC USINT about remaining problematic ACIS configurations in cycle 24.

  ...  Tested condensed version of OR list against or2simodes.  Test successful.

  ...  Checking on automated processes associated with SACGS.