1. GLAST LAT Project ISOC Peer Review - March 2, 2004 Document: LAT-PR-03213-01 Section 3 LOF Operations Concept 1 Gamma-ray Large Area Space Telescope GLAST Large Area Telescope ISOC Peer Review 3.0 LOF Operations Concept Lori Bator ISOC Chief Engineer

2. GLAST LAT Project ISOC Peer Review - March 2, 2004 Document: LAT-PR-03213-01 Section 3 LOF Operations Concept 2 Topics 3.1 Instrument Operation 3.2 Command and Telemetry Operations –Housekeeping Telemetry –Thermal Control System –Commanding –Flight Software Maintenance 3.3 Operations Products

3. GLAST LAT Project ISOC Peer Review - March 2, 2004 Document: LAT-PR-03213-01 Section 3 LOF Operations Concept 3 Gamma-ray Large Area Space Telescope GLAST Large Area Telescope ISOC Peer Review 3.1 Instrument Operations Lori Bator ISOC Chief Engineer

4. GLAST LAT Project ISOC Peer Review - March 2, 2004 Document: LAT-PR-03213-01 Section 3 LOF Operations Concept 4 LAT Operation Phases Ref: LAT Mission Phases (LAT-TD-00501) Launch and Early Orbit (Phase 0) –Instrument test teams will augment the Flight Operations Team (FOT) Staffed around the clock for the initial checkout, transition to prime shift only operation by end of phase –Instrument state turn-on occurs after solar array deployment –Instrument activation and functional checkout – 20 days Test various trigger modes of the instruments Perform initial instrument alignments Verify all observatory observation modes Characterize data volumes –Science commissioning period – 30 days Characterize initial science performance using pointed observation mode and known targets Verify sky survey (scanning) mode and a multiple target mode involving scan-pointing

5. GLAST LAT Project ISOC Peer Review - March 2, 2004 Document: LAT-PR-03213-01 Section 3 LOF Operations Concept 5 LAT Operation Phases, cont’d Verification and Sky Survey (Phase 1) –One year –Fully characterize, validate, and verify science instruments –Primarily operate in sky survey mode –Science calibration Science Observation (Phases 2-5) –Guest observation period for remaining mission life End of life

6. GLAST LAT Project ISOC Peer Review - March 2, 2004 Document: LAT-PR-03213-01 Section 3 LOF Operations Concept 6 LAT Modes

7. GLAST LAT Project ISOC Peer Review - March 2, 2004 Document: LAT-PR-03213-01 Section 3 LOF Operations Concept 7 LAT Modes, cont’d

8. GLAST LAT Project ISOC Peer Review - March 2, 2004 Document: LAT-PR-03213-01 Section 3 LOF Operations Concept 8 LAT Modes, cont’d Launch Mode and Early Orbit Modes Standby/Engineering Mode –Engineering Sub-Mode Used for troubleshooting and diagnostics, initiating the use of new software loads, and raw data downlinks –Calibration Sub-Mode LAT performs Charge Injection (CI) for on-board calibration and support raw data collection –South Atlantic Anomaly (SAA) Safe Mode

9. GLAST LAT Project ISOC Peer Review - March 2, 2004 Document: LAT-PR-03213-01 Section 3 LOF Operations Concept 9 LAT Modes, cont’d Observation Modes –Sky Survey Sub-Mode Zenith Pointing (Pointed Observation) Rocking –Pointed Observation Sub-Mode Z-axis of the observatory is pointed to a commanded celestial target –Repoint Sub-Mode Target of Opportunity (TOO) Repointed Observation Autonomous repoint for a gamma-ray burst Safe Modes –Hardware –Survival (LAT powered off)

10. GLAST LAT Project ISOC Peer Review - March 2, 2004 Document: LAT-PR-03213-01 Section 3 LOF Operations Concept 10 Gamma-ray Large Area Space Telescope GLAST Large Area Telescope ISOC Peer Review 3.2 Command and Telemetry Operations Lori Bator ISOC Chief Engineer

11. GLAST LAT Project ISOC Peer Review - March 2, 2004 Document: LAT-PR-03213-01 Section 3 LOF Operations Concept 11 Housekeeping Telemetry Housekeeping data consists of –Environmental monitors Temperature, voltage, current –Low rate science Counters, deadtime, error messages, status, event statistics –Communications Statistics Command response, traffic counters –CPU Metrics SIU and EPU monitoring

12. GLAST LAT Project ISOC Peer Review - March 2, 2004 Document: LAT-PR-03213-01 Section 3 LOF Operations Concept 12 Housekeeping Telemetry, cont’d HK data is collected according to a schedule loaded in flight software –Collection of telemetry depends on configuration tables and FSW operational modes Boot mode provides small amount of status and error reporting during SIU boot Operational mode provides full set of HK data collecting at nominal rates Science acquisition mode utilizes the operational parameters plus increased low-rate science counter collection rates Safe mode configuration collects only critical data necessary for health assessment and failure diagnostics –Schedule identifies the order and type of packets Autonomous and commanded collection schedules

13. GLAST LAT Project ISOC Peer Review - March 2, 2004 Document: LAT-PR-03213-01 Section 3 LOF Operations Concept 13 Housekeeping Telemetry, cont’d HK data is monitored according to limit tables Configuration files can be uploaded to modify the collection table, schedule table, and limit table Commands can be sent to enable or disable threshold checking, alarming, and alarm response actions Commands are sent to request specific telemetry packets (demand telemetry)

14. GLAST LAT Project ISOC Peer Review - March 2, 2004 Document: LAT-PR-03213-01 Section 3 LOF Operations Concept 14 Thermal Control System Thermal Control System (TCS) is implemented by LAT flight software to fine-tune the thermal profile of the LAT with the goal of minimizing distortions of the mechanical structure –Design of TCS is described in LAT-SS-02896 Two temperature sensors and one heater controller on each of 12 heat pipes on each of two radiators –TCS turns heaters on or off for a fixed period of time –Watchdog timer activates if TCS does not get any input after one minute

15. GLAST LAT Project ISOC Peer Review - March 2, 2004 Document: LAT-PR-03213-01 Section 3 LOF Operations Concept 15 Telemetry Control System (TCS) Modified through uploads to tables –Mapping Table identifies sensors electronically –Parameter Table identifies which sensors are used by TCS and the limits for each TCS monitoring data included in housekeeping telemetry –Active sensor and heater status –TCS state information –Temperature values

16. GLAST LAT Project ISOC Peer Review - March 2, 2004 Document: LAT-PR-03213-01 Section 3 LOF Operations Concept 16 Commanding Structure File uploads –Primary method of getting instructions into the LAT Configuration changes Calibrations –Generate file uploads using data from SOG –Files are validated on test bed –Human-readable information sent with data file when transmitted to the GSSC File name Description of what it does Size of file Time conditions Criticality

17. GLAST LAT Project ISOC Peer Review - March 2, 2004 Document: LAT-PR-03213-01 Section 3 LOF Operations Concept 17 Commanding Structure, cont’d Single command or group of single commands –Used for specific tasks File upload (start, cancel, delete, copy, commit) Memory dump Boot commands Diagnostic and test commands –Often involve parameters to identify memory location, units, names of files, etc. –Commands are identified by file mnemonics in a procedure provided to GSSC Procedure identifies activity, command parameters, time conditions, and criticality Procedure is validated on test bed Commands generated by FOT using LAT database information

18. GLAST LAT Project ISOC Peer Review - March 2, 2004 Document: LAT-PR-03213-01 Section 3 LOF Operations Concept 18 Command Planning Instrument plan and the associated operations procedures are provided to GSSC –Format of this communication is being developed and will be documented in the Operations Data Products ICD GSSC generates the integrated observatory schedule and must have knowledge of whether the instrument activity affects pointed observations or impacts the TDRS schedule

19. GLAST LAT Project ISOC Peer Review - March 2, 2004 Document: LAT-PR-03213-01 Section 3 LOF Operations Concept 19 Command Scheduling Concept

20. GLAST LAT Project ISOC Peer Review - March 2, 2004 Document: LAT-PR-03213-01 Section 3 LOF Operations Concept 20 Command Timeline Concept

21. GLAST LAT Project ISOC Peer Review - March 2, 2004 Document: LAT-PR-03213-01 Section 3 LOF Operations Concept 21 Database LOF is responsible for the command and telemetry database during operations Database is initially being developed by the Flight Software group for use in FSW development –Developed an XML-based representation of the command and telemetry database –Includes an editor tool to manipulate the XML files –Includes extraction tools to produce ITOS database interchange records (format documented in Database Format Control Document (DFCD)) Database documentation Source code for inclusion in FSW applications Command and telemetry database will be further developed for I&T and ISOC use by I&T, ISOC, and system engineering

22. GLAST LAT Project ISOC Peer Review - March 2, 2004 Document: LAT-PR-03213-01 Section 3 LOF Operations Concept 22 Database, cont’d LAT delivers database to Spectrum Astro in format identified by DFCD prior to spacecraft integration and provides updates prior to launch ISOC delivers post-launch updates to MOC in format identified by DFCD and Operation Data Products ICD Database will be under configuration control –On-orbit changes must be approved by Operations CCB Initial validation occurs during I&T –After I&T and during on-orbit operations, changes will be validated on the test bed

23. GLAST LAT Project ISOC Peer Review - March 2, 2004 Document: LAT-PR-03213-01 Section 3 LOF Operations Concept 23 Flight Software LOF is responsible for maintaining the Instrument Flight Software on-orbit –Status of on-board software –Verification and validation of uploads –Development of software patches Section 4.2 will describe the tools that will be used by LOF

24. GLAST LAT Project ISOC Peer Review - March 2, 2004 Document: LAT-PR-03213-01 Section 3 LOF Operations Concept 24 Gamma-ray Large Area Space Telescope GLAST Large Area Telescope ISOC Peer Review 3.3 Operations Products Lori Bator ISOC Chief Engineer

25. GLAST LAT Project ISOC Peer Review - March 2, 2004 Document: LAT-PR-03213-01 Section 3 LOF Operations Concept 25 Operations Products Operations Products from MOC Operations Products from ISOC

26. GLAST LAT Project ISOC Peer Review - March 2, 2004 Document: LAT-PR-03213-01 Section 3 LOF Operations Concept 26 Operations Products from MOC Level 0 Data –After each pass, MOC processes virtual channel telemetry frames received via White Sands or ground network stations to create individual Level 0 packet files –MOC notifies ISOC of availability of Level 0 data within four hours Real-time (RT) Housekeeping Data –Provided by MOC through a separate Internet socket –Need for RT data at ISOC is under review Remote access to RT and archived data at MOC –View RT telemetry during a contact using ITOS Java display pages over the Internet –Use of Data Trending and Analysis System to view plots and tables of HK and trend data

27. GLAST LAT Project ISOC Peer Review - March 2, 2004 Document: LAT-PR-03213-01 Section 3 LOF Operations Concept 27 Operations Products from MOC, cont’d Integrated Observatory Timeline –Text listing of commands contained in the ATS loads along with predicted orbital events As-Flown Timeline –Actual observation times and attitude data from the spacecraft Solid State Recorder (SSR) Observatory Telemetry and Command Database Updates –Updates to the project database, which includes spacecraft and GBM parameters –Database changes are approved by Operations CCB –Updates are made available on MOC file server in format documented in DFCD

28. GLAST LAT Project ISOC Peer Review - March 2, 2004 Document: LAT-PR-03213-01 Section 3 LOF Operations Concept 28 Operations Products from MOC, cont’d LAT Memory Dumps –LOF is notified when and where to retrieve memory dump data from MOC web server MOC Command Logs –ASCII text files of all commands sent to the spacecraft Flight Dynamics Orbital Products –TDRSS and GLAST ephemerides Anomaly Reports –MOC notifies the LOF of any spacecraft or instrument anomaly

29. GLAST LAT Project ISOC Peer Review - March 2, 2004 Document: LAT-PR-03213-01 Section 3 LOF Operations Concept 29 Operations Products from ISOC Data Retransmission Requests –Text notification to MOC to request a retransmission of Level 0 data LAT Telemetry and Command Database Updates –Approved by Operations CCB –Validated on test bed –Format as defined in DFCD LAT Anomaly Incident Reports –LOF notifies MOC of instrument anomalies –Text files of LAT anomalies made available to MOC

30. GLAST LAT Project ISOC Peer Review - March 2, 2004 Document: LAT-PR-03213-01 Section 3 LOF Operations Concept 30 Operations Products from ISOC, cont’d LAT Operations Procedures –Provided to GSSC during on-orbit operations and provided to MOC during early-orbit testing and during contingencies if necessary –Used to identify instrument activities Involve instrument commands, but could also be used to identify special monitoring situations Handle routine, one-time use, test, and contingency situations Where possible, procedures derive from I&T tests –Configuration controlled by LOF –Validated on test bed, or during I&T when applicable

31. GLAST LAT Project ISOC Peer Review - March 2, 2004 Document: LAT-PR-03213-01 Section 3 LOF Operations Concept 31 Operations Products from ISOC, cont’d –LAT Operations Procedures are in human readable format as defined in GSFC Doc #492-MOC-004 GLAST Project Procedure/PROC Style Guide Purpose and description of activity References Initial and final conditions Cautions and constraints Identification of child/parent procedures Step by step list of actions with command –Individual command mnemonics with parameters –Names of command upload data files –Expected response for each step –Comments including relevant contingency procedures, reference material, etc.

32. GLAST LAT Project ISOC Peer Review - March 2, 2004 Document: LAT-PR-03213-01 Section 3 LOF Operations Concept 32 Conclusions Flight software definitions for command and telemetry are in place Have concepts for managing and scheduling instrument commanding –LAT Operations Plan (LAT-SS-01378) in draft –Operations Data Products ICD (492-MOC-0009) in draft ISOC will be hiring a software engineer to help develop the database with I&T Interfaces have been identified in the Operations Data Products ICD – continue to update the plan and work out the details