LAT Operations Scenario Subsystem Meetings

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LAT Operations Scenario Subsystem Meetings
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Agenda

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

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LAT Operations Phases

• IT
• Pre-FSW
• Post-FSW
• Spectrum
• LEO
• LAT turn-on
• Initial checkout
• First year
• Survey mode
• Second and subsequent years
• Pointed observation
• Survey mode

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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

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How the ISOC Commands the LAT
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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

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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?

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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