LAT Operations Scenario Subsystem Meetings

Agenda Define LAT operation phases Overview of LAT commanding Describe subsystem operations Identify potential contingencies and actions Identify MOC monitoring and activities

LAT Operations Phases I&T Pre-FSW Post-FSW Spectrum L&EO LAT turn-on Initial checkout First year Survey mode Second and subsequent years Pointed observation

LAT Commanding during On-orbit Operations ISOC identifies one or more command mnemonics and any associated parameters and upload files to accomplish the desired function Command and files are validated on testbed Command mnemonics and files are transmitted to GLAST Science Support Center (GSSC) Integrate guest investigator requests and instrument commands into observatory timeline Send command information to MOC MOC schedules TDRS link for commanding (or use a pass routinely scheduled for SSR dump) MOC uses ITOS and LAT database to create LAT commands from the command mnemonics Commands are loaded into an Absolute Time Sequence (ATS) that is transmitted to spacecraft Spacecraft sends ATS commands to LAT at the assigned times Files are uploaded in real time and may be committed at that time or later via an ATS command

How the ISOC Commands the LAT

Subsystem Operations What subsystem-related commanding occurs during: Initial checkout Survey mode Pointed observation Scope of commanding How many commands per day, week or month? Size of files Real-time or ATS Are there any special requirements? Pointing dependency (attitude dependency impacts TDRS scheduling) Criticality of commanding

Contingency Plans What are some possible anomalous conditions? Symptoms of a problem What data is being monitored by LAT? What data is being monitored by spacecraft? What needs to be monitored by MOC/ISOC?

MOC Responsibilities What housekeeping data would MOC look at? What diagnostic data would be meaningful for MOC? What response does MOC take for alert data? Notify ISOC and perform contingency procedure Notification only