When To Use The Non-Load Event Tracking GUI

Intoduction

The Non-Load Event Tracking System allows the ACIS Ops team to track and record thermally consequential events that occur which are not found in the load. This includes SCS-107's (both Autonomous and Manual), "Full Stops" such as Normal Sun Modes, Bright Star Holds, and CAPs using CLD files we might run (both Long Term CTI runs as well as others). TOO load transitions are included too for human consumption. These entries are not used in the assembly of backstop histories. The major reason for recording these events in a tracking file is to allow thermal models to take thermally relevant events into account.

TOO's and SCS 107's of any kind (manual or autonomous, radiation, BSH, NSM etc.) are recorded automatically by history-files.pl when you run it. So you needn't worry about recording those events in the system.

The same is true for when you run history-files.pl -go. That's recorded in the Non Load Event Tracking file. So you don't have to worry about that

Tasks You MUST Perform

Events which are not automatically recorded are:

LTCTI and other CAPs which use CLD files.
A thermally consequential maneuver such as a pitch change during a shutdown.

Scenarios

Scenario #1: Long Term CTI Measurements During a Shutdown

Chandra was shut down due to either a radiation SCS-107, or BSH or NSM. When you run history-files.pl that event is automatically recorded in the NonLoadTrackedEvents.txt tracking file.

If you do not run a LTCTI run during the shutdown, and if the OCC does not command a pitch change maneuver - you do nothing more. If you execute a LTCTI, you should prep the CAP, get it reviewed, execute the CAP,
write and email your shift report
Immediately after emailing your shift report, you need to run the NLET tool:

How To Operate the Non-Load Event Tracking GUI

You want to do that ASAP so that any and all users of the Tracking file
including you, have the most up to date status of events. Thermal models
rely on having the latest available status and they will use the tracking file to get that.

Scenario #2: OCC-Commanded Maneuver Changing Spacecraft Pitch

Chandra was shut down due to either a radiation SCS-107, or BSH or NSM. When you run history-files.pl that event is automatically recorded in the NonLoadTrackedEvents.txt tracking file. Occasionally the spacecraft will be maneuvered away from a non-optimal pitch to a better one. You MUST record this event in the Official Non Load Event Tracking file.

Scenario #3: What-if Testing To Determine The Best LTCTI CLD File To Use

You are in the middle of a shutdown and you think a LTCTI is possible.
But you need to select the number of chips to use (4,5, or 6)
and sometimes even the length of the LTCTI run to be sure that
the measurement doesn't violate any thermal limits.

Copy the OPERATIONAL NonLoadTrackedEvents.txt file into some
other directory in order to have the latest version. Then use
the NLET.py tool to add on LTCTI entries into your test tracking file.

To do this you use the TEST button on the LTCTI GUI page.

Feed the test tracking file into one or more thermal models of
your choice using the --nlet_file switch. (The default for this switch is the OFFICIAL NLET file).