1. LAT Operations Scenario Subsystem Meetings

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

3. 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

4. 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

5. How the ISOC Commands the LAT

6. 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

7. 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?

8. 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