GLAST LAT Project CDR/CD-3 Review May 12-16, 2003 Document: LAT-PR-01967 Section 5 IOC Subsystem 1 GLAST Large Area GLAST Large Area Telescope: Telescope: IOC Subsystems WBS: 4.1.B David Lung Stanford Linear Accelerator Center IOC Subsystem Manager [email protected]Gamma-ray Large Gamma-ray Large Area Space Area Space Telescope Telescope
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GLAST Large Area Telescope: IOC Subsystems WBS: 4.1.B David Lung
Gamma-ray Large Area Space Telescope. GLAST Large Area Telescope: IOC Subsystems WBS: 4.1.B David Lung Stanford Linear Accelerator Center IOC Subsystem Manager [email protected]. Topics. IOC Overview Key Events Interfaces Requirement flow Data path Commanding path - PowerPoint PPT Presentation
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GLAST LAT Project CDR/CD-3 Review May 12-16, 2003
Document: LAT-PR-01967 Section 5 IOC Subsystem 1
GLAST Large Area Telescope:GLAST Large Area Telescope:
IOC SubsystemsWBS: 4.1.B
David LungStanford Linear Accelerator CenterIOC Subsystem Manager
• The command and telemetry database is being developed by Flight Software (FSW) for engineering model testing– The schema describing commands and telemetry will
written in a standard meta language (XML or MySQL)– The choice of meta language will be influenced by the ease
of creating/changing/maintaining the data base. – Schema design will be driven by the details of the ITOS and
AstroRT data bases - We must have the ability to translate to either
• Close coordination between FSW, I&T and IOC • IOC will build upon and maintain the software and
LAT OperationsGamma-ray Large Gamma-ray Large Area Space Area Space TelescopeTelescope
GLAST LAT Project CDR/CD-3 Review May 12-16, 2003
Document: LAT-PR-01967 Section 5 IOC Subsystem 12
Launch ConditionsLaunch Conditions
• LAT instrument is OFF from pre-launch through spacecraft solar array deployment and thermal stabilization
• 96 telemetry points will be used for LAT monitoring via the spacecraft bus prior to LAT turned-on– Temperature– Voltages
• S/C unregulated survival feeds enabled the following LAT heaters
– Radiator Antifreeze– Grid Make-up
• Post S/A deployment and first contact, the S/C PRU will enable the regulated VCHP feed
– VCHP reservoir heaters
GLAST LAT Project CDR/CD-3 Review May 12-16, 2003
Document: LAT-PR-01967 Section 5 IOC Subsystem 13
LAT Analog TelemetryLAT Analog Telemetry
LAT-SS-00890 Draft LAT Instrumentation Plan
PRELIMINARY - NOT YET APPROVED Rev Date: 03-Mar-02Print Date: 09-Apr-03
Description of Instrumentation Source of InstrumentationResistance Side of Spacecraft PDU
Description Group Type Part No. Min/Max Resolution Accuracy Range SS Location Shield SC-Pri SC-Sec
ACD Tiles Thermal RTD -100/100 1.0 C 0-5000 ACD Top/Sides of ACD on tiles Out 5 5Radiators Thermal RTD -100/100 1.0 C 0-5000 Mech On Radiator panels/VCHP's Out 8 8VCHP's Reservoir Htr Thermal RTD -100/100 1.0 C 0-5000 Mech VCHP reservoir htr's Out 12 12ACD TSA Shell (inside) Thermal Thermistor YSI-44909 -40/60 0.25 C +/- 1.0 % R 7599 -884.6K ACD Insides of ACD Shell facing TKR In 5 5ACD PMT Rail Thermal Thermistor YSI-44909 -40/60 0.25 C +/- 1.0 % R 7599 -884.6K ACD ACD PMT Rail structure in BEA Out 4 4SIU Thermal Thermistor YSI-44909 -40/60 0.25 C +/- 1.0 % R 7599 -884.6K Elec SIU box at interface to X-LAT Pl In 2 2PDU Thermal Thermistor YSI-44909 -40/60 0.25 C +/- 1.0 % R 7599 -884.6K Elec PDU box at interface to X-LAT Pl In 2 2GASU Thermal Thermistor YSI-44909 -40/60 0.25 C +/- 1.0 % R 7599 -884.6K Elec GASU box at interface to X-LAT Pl In 2 2Grid-Radiator interface Thermal Thermistor YSI-44909 -40/60 0.25 C +/- 1.0 % R 7599 -884.6K Mech Rad Mnt Bkt end, base, Grid corner Out 4 4Grid Make-up Heaters Thermal Thermistor YSI-44909 -40/60 0.25 C +/- 1.0 % R 7599 -884.6K Mech Corners of Grid at thermostat location Out 4 4VCHP-XLHP interface Thermal Thermistor YSI-44909 -40/60 0.25 C +/- 1.0 % R 7599 -884.6K Mech VCHP-XLHP at bolted joint Out 4 4X-LAT Plate Thermal Thermistor YSI-44909 -40/60 0.25 C +/- 1.0 % R 7599 -884.6K Mech Top side of X-LAT Plate on heat pipes Out 4 4SIU Pri/Sec 3.3/5V V Voltage Elec SIU Pri/Sec 3.3/5V V In 2 2PDU Pri/Sec 3.3V V Voltage Elec PDU Pri/Sec 3.3V V In 2 2GASU Pri/Sec 3.3/28V/3.3VA VVoltage Elec GASU Pri/Sec 3.3/28V/3.3VA V In 2 2VCHP Reservoir Htr Pri/Sec Voltage Mech VCHP Reservoir Htr Out 4 4LAT SIU Bus V Pri/Sec Voltage Elec SC Output to SIU Bus Out 2 2LAT VCHP Bus V Pri/Sec Voltage Elec SC Output to VCHP Bus Out 2 2Spare Voltage Channels Voltage 18 18Spare Temp. Channels Thermal Thermistor 8 8Total 96 96For Thermistors, zero power resistance @25 C is 30000 ohmsTest Plug is for fly-away instrumentation (used only for ground test but not removed for flight)Light green shading indicates LAT-relevent monitoring performed internally by the spacecraft.All voltages are 0-5V or 0-x V, wait til SA suggests what is convenient for them.
GLAST LAT Project CDR/CD-3 Review May 12-16, 2003
Document: LAT-PR-01967 Section 5 IOC Subsystem 14
LAT Turn On State DiagramLAT Turn On State Diagram
Off Pre-deployLAT
SurvivalLAT Hardware Safe T&DF On Detectors On Standby Observing
• Once the spacecraft has establish power positive, thermal stabilization, and out-gassing - the LAT instrument shall be turned-on
• The LAT turn-on is a set of ground command with verification sequences
– Verify telemetry prior to the next operation
• Temperatures• Voltages/Currents• Turn-on profiles• State
• Additional monitoring telemetry are available as the PDU, GASU, and TEMs are turned-on
– PDU: 157– GASU: 57– TEM: 640
HEATERSRadiator Antifreeze
Grid M ake-upVCHP
SIU A On
PDU A On
GASU A On
EPU A/B On
TEM (s) On
ACD On
Tracker Tower 1 On
Tracker Tower 16 On
CAL M odule 1 On
CAL M odule 16 On
TLM CheckVerify Turn-On Profile
TLM CheckVerify Turn-On Profile
TLM CheckVerify Turn-On Profile
TLM CheckVerify Turn-On Profile
Turn-On SequenceSee Turn On Sequence Note
Turn-On SequenceBEA On
ACD FEE Individual Turn-On
Turn-On SequenceSee Turn-On Sequence Note
Turn-On SequenceSee Turn On Sequence Note
Spacecraft PowerFeed 5, 7 & 8
Enabled
Spacecraft PowerFeed 1 & 2
Enabled
Spacecraft PowerFeed 3 & 4
Enabled
Spacecraft LAT
Group 1
Group 2
Group 3
Note:Turn On Sequence (Proposed)
Turn On group A (the center fourTEMs/Trackers/CAL Modules)
Turn On group B (the +Y face) Turn On group C (-Y face) Turn On group D (+X face) Turn On group E (-X face)
A A
A A
B B B
CCC
D
D
D
E
E
E
GLAST LAT Project CDR/CD-3 Review May 12-16, 2003
Document: LAT-PR-01967 Section 5 IOC Subsystem 16
• Data acquisition– Rocking– Pointed observation– Repoint
• Prior to entering the pre-defined South Atlantic Anomaly (SAA) event, the spacecraft sends LAT a signal safing the high-voltage power supplies within the ACD PMT
• Return to data acquisition upon exiting SAA
• Approximately 6 contacts per day, less than 10 minutes per pass