GLAST LAT Project
ISOC CDR, 4 August 2004
GLAST Large Area Telescope:
Gamma-ray Large
Area Space
Telescope
Instrument Science Operations Center
CDR
Section 3.1
Command, Health and Safety Design
Lori Bator
ONE-SLAC
ISOC Lead Engineer
lbator@slac.stanford.edu
(650) 926-5352
Document: LAT-PR-04500
Section 3.1
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GLAST LAT Project
ISOC CDR, 4 August 2004
Topics
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Overview of CHS
CHS System
ISOC S/W Architecture
CHS Team
Internal Coordination
External Interfaces
Documents
Status
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GLAST LAT Project
ISOC CDR, 4 August 2004
Overview of CHS
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Commanding
– Generation and validation of commands and command
sequences
– Passing commands on to the GSSC (and to MOC for early
orbit operations and contingency commanding)
– Verifying these commands were executed
– Logging and archiving of all commands
– Configuration and control of command plans, procedures
and command database
Health and Safety
– Receive and archive Level 0 data from the MOC
– Monitor data to ascertain and track the health and safety of
the instrument
– Continuous knowledge of the configuration of the LAT
– Configuration and control of telemetry database
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GLAST LAT Project
ISOC CDR, 4 August 2004
CHS System
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ITOS used for command, health and safety functions
– HK data limit checking
– Telemetry and command definition file validation
– Command load verification and validation
Other tools (discussed in section 5)
– Level 0 receipt and archiving
– HK trending
– Data transmission
– Mission planning and generation of file uploads
– Anomaly tracking and notification
– Relational database queries for trending and analysis
– Configuration management tools
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GLAST LAT Project
ISOC CDR, 4 August 2004
Architecture Drivers
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Drivers
– Minimize V&V burden and total cost
– Maintain all science capabilities
– Simplify interfaces and allow early testing
Recognized that neither of the previously considered options
were particularly attractive
– ITOS/Commercial packages don’t accommodate
complexities of science data
– Homegrown system doesn’t have heritage
• Most of additional code needed duplicates that in
existing packages
– Studied hybrid solutions
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GLAST LAT Project
ISOC CDR, 4 August 2004
ITAR Issues Using ITOS
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Workstations running ITOS
– Password protected
– File access controlled through permissions
User access to ITOS data display and analysis is through a
non-ITAR controlled web interface
No impact on collaboration
SLAC has developed an official policy on ITAR issues that
specifically addresses the use of ITOS within the ISOC.
Availability of non-ITAR web interfaces to the data address all
concerns based on Stanford and SLAC openness policies and
the use of ITOS within the ISOC is approved.
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GLAST LAT Project
ISOC CDR, 4 August 2004
CHS Team (1/3)
CHS
Team Lead
Instrument
Physicist
(part time PVO)
Document: LAT-PR-04500
Software
Engineer
Operator #1
Section 3.1
Operator #2
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GLAST LAT Project
ISOC CDR, 4 August 2004
CHS Team (2/3)
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Weekday, day-time operations
– Operator shift coverage
• 5 am to 2 pm to cover MOC shift times on East Coast
• 9 am to 6 pm to cover ISOC internal coordination needs
– On-call support
• Operators for real-time commanding or anomaly support
• Software engineer for emergency software support
• Team Lead and Instrument Physicist for anomalies
Instrument Physicist
– Monitor HK data for impact on science
– Monitor and maintain configuration of instrument
– Schedule instrument commanding
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GLAST LAT Project
ISOC CDR, 4 August 2004
CHS Team (3/3)
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Software Engineer Responsibilities
– Maintain ITOS configuration and other CHS tools
– Maintain configuration control of command and telemetry
database
Operator Responsibilities
– Generate command plans
– Interface with MOC and GSSC
– Monitor CHS system processes
– Monitor real-time contacts during the shift
– Monitor automated report generation
– Respond to notification of alerts and anomalies
– Serve as backup for Software Engineer to address system
problems
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GLAST LAT Project
ISOC CDR, 4 August 2004
Internal Team Coordination
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With PVO
– Health and status of LAT
– Calibration requirements and scheduling
– Weekly schedule of command activities
– LAT commanding history
– Interpretation of diagnostic data
 With FSW
– Verification and validation of command plans
– Configuration control of state of instrument
– Configuration control of FSW
– Configuration control of telemetry and command database
– Interpretation of diagnostic data
 With Science Products
– Health and status of LAT
– “Quick look” data
– Retransmission requests
– Interface with GSSC and MOC
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GLAST LAT Project
ISOC CDR, 4 August 2004
External Interfaces
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Defined by
– Operational Data Products ICD (492-MOC-009)
– Mission Operations Agreement for Roles and Responsibilities
Element level Operation Agreements
 GSSC
– Science planning (phase 2)
– Commanding (phase 1 and 2)
 MOC
– Level 0 data
– Real-time HK downlink
– Mission planning products
• As-flown timeline
• Planned TDRSS schedule
• Orbit elements
– Database updates
– Commanding (phase 0 and contingency)
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GLAST LAT Project
ISOC CDR, 4 August 2004
Ops Data Products: ISOC – MOC
Level 0 Data
ISOC
RT HK Telemetry
MOC
Flight Dynamics Products
Integrated Observatory Timeline
As-flown Timeline
PDB Updates
LAT Alerts
LAT Instrument Commands
LAT Instrument Loads
LAT Instrument Procedures
Anomaly Reports
LAT Incident Reports
Data Retransmission Request
LAT T&C Database Updates
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GLAST LAT Project
ISOC CDR, 4 August 2004
Ops Data Products: ISOC – GSSC
ISOC
GSSC
LAT Timelines
LAT Instrument Commands
LAT Instrument Loads
Science Plan
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GLAST LAT Project
ISOC CDR, 4 August 2004
Documents
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Instrument Operations Handbook (ECD: Oct 2005)
– First iteration is for use with I&T – in work
On-orbit Operations Procedures (ECD: L – 6 months)
Launch and Early Orbit Operations (ECD: L – 3 months)
LAT Telemetry and Command Handbook (ECD: Jan 2005)
– Document created using FSW development tools
All documents will have intermediate drafts
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GLAST LAT Project
ISOC CDR, 4 August 2004
Current Status
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ITOS installed on one workstation
– Demo in section 5
Other CHS tools exist or are in development
– Described in section 5
Technical writer hired to produce ISOC documentation,
including CHS documents
Software engineer hired to implement ISOC databases
– Telemetry and command descriptions have been defined by
FSW
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GLAST LAT Project
ISOC CDR, 4 August 2004
Backup Slides
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GLAST LAT Project
ISOC CDR, 4 August 2004
ITOS/Astro RT Trade
PRO
Either • Provide basic instrument
health and safety functions
• Telemetry display
• EU conversion
• Limit checking and
monitoring
• Command and telemetry
database access
CON
• ITAR issues
• Requires use of ITOS- or
AstroRT- specific interfaces
and scripting languages
• Limitations on ability to
work with science and
instrument diagnostic data
• Have learnable interfaces and
scripting
• AstroRT uses LabView for
display and Perl scripts for
automation
• ITOS displays are reportedly
easy to create, uses STOL for
input
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GLAST LAT Project
ISOC CDR, 4 August 2004
ITOS/Astro RT Trade
PRO
AstroRT
•
ITOS
•
LAT is using AstroRT for
LAT flight software
testing
MOC and GBM using
ITOS
• Able to have ITOS
changes made for us
Document: LAT-PR-04500
CON
•
Commercial product costing
$$$ upfront and for support
throughout program life
•
None that don’t also exist for
AstroRT
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