LAT ISOC
Gamma-ray Large Area
Space Telescope
ISOC Review, 15 February 2006
GLAST Large Area Telescope
Instrument Science Operations Center
Introduction to GLAST and the LAT ISOC
Rob Cameron
Stanford Linear Accelerator Center
ISOC Manager
rac@slac.stanford.edu
650-926-2989
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LAT ISOC
ISOC Review, 15 February 2006
Outline
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Organization of Review Presentations
Overview of GLAST
Overview of the Large Area Telescope
Overview of the ISOC
– ISOC and the LAT Collaboration
Pre-launch ISOC Activities
– LAT I&T Support Activities
Post-launch ISOC Activities
ISOC Operations Facility and office areas at SLAC
Summary
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LAT ISOC
ISOC Review, 15 February 2006
Organization of Presentations
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Introduction to GLAST and the LAT ISOC
Flight Software Systems
Commanding, Health and Safety
Science Operations I
Science Operations II
Science Analysis Systems
Calibration Unit Beam Test
ISOC Budget and Staffing
Rob Cameron
Jana Thayer
Rob Cameron
Eduardo do Couto e Silva
Seth Digel
Richard Dubois
Eduardo do Couto e Silva
Rob Cameron
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LAT ISOC
ISOC Review, 15 February 2006
Gamma Ray Large Area Telescope

Next observatory to be
launched by NASA
– Fall of 2007

Extends the scientific reach
in the gamma-ray spectrum
– Higher energy
– Greater sensitivity
– Better resolution

Next in a series of space-based observatories that cover the EM
spectrum from microwaves through gamma rays
– WMAP, Spitzer, Hubble, Chandra, SWIFT, GLAST

Windows on the Universe
– Improved capability to study the time evolution of the energy
spectra of transient phenomena
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LAT ISOC
ISOC Review, 15 February 2006
GLAST Mission Summary
Larger field of view (FOV), higher sensitivity, and broader energy detection range than any
previously flown gamma-ray mission


Science Exploration
– AGNs
– SNRs as particle accelerators
– Pulsars
– Starlight emission history of the Universe
– Highest-energy gamma-ray bursts
– Our Sun as a particle accelerator
– The new energy window: Particle Dark Matter; other Big Bang relics? New physics?
Mission Duration: 5 years (10 year Goal)
 Orbit:
565 km Circular, 28.5° Inclination
 Launch Date:
Fall 2007
 Launch Vehicle:
Delta 2920H-10
 Launch Site:
Kennedy Space Center

Sky survey + pointed observing programs
 Autonomous targeted re-pointing capability, with fast slew speed
– 75° in <10 minutes (5 minutes goal)

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LAT ISOC
ISOC Review, 15 February 2006
GLAST Science Instruments
Large Area
Telescope
(LAT)
Two GLAST instruments:
LAT: 20 MeV – >300 GeV
GBM: 10 keV – 25 MeV
LAT
pair conversion telescope

Tracker
GLAST Burst Monitor (GBM)
GBM
ACD
[surrounds 4x4
+
array of TKR e
towers]
e–
Grid
Calorimeter
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LAT ISOC
ISOC Review, 15 February 2006
Observatory Layout
+Z (Yaw)
Launch Config.
LAT
+Y
(Pitch)
+X
(Roll)
LAT Radiator
Optical Bench
and Skirt
Assembly
3 Star Trackers
and SIRU
Hydrazine Propellant Tank
GBM NaI Detectors (x12)
GBM Power
Supply Box
3 Panel Solar Array
GBM Data
Processing Unit
GBM BGO Detector (x2)
Single Axis S/A Drive
S-Band Antennas
125 Ahr Battery
Ku-Band Antenna
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LAT ISOC
ISOC Review, 15 February 2006
LAT Master Schedule

LAT complete and tested
March 2006
– To Naval Research Laboratory for
environmental testing

Delivery to Observatory Integration
June 2006
– Mate with spacecraft and GBM and test

Launch
– Kennedy Space Center
Fall 2007
Spitzer Launch on a
Delta II
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LAT ISOC
ISOC Review, 15 February 2006
Large Area Telescope Structure
Anti Coincidence Detector -- GSFC
16 Tracker Modules – UCSC, Italy &
Japan
Grid -- SLAC
16 Calorimeter Modules – NRL &
France and Sweden
Electronics Modules -- SLAC
Radiators -- SLAC
Integration and Test -- SLAC
Mass
Power
3000 Kg
650 Watts
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LAT ISOC
ISOC Review, 15 February 2006
LAT Overview: Design

Si Tracker
ACD
pitch = 228 µm
8.8 x105 channels
12 layers × 3% X0
+ 4 layers × 18% X0
+ 2 layers
89 Segmented
scintillator tiles
0.9997 efficiency
 minimize self-veto
e+
Grid & Thermal
Radiators
e–
CsI Calorimeter
3000 kg, 650 W (allocation)
1.8 m  1.8 m  1.0 m
1.2 Mb/s telemetry data rate
1536 CsI(Tl) bars
Hodoscopic array
8.4 X0 8 × 12 bars
2.0 × 2.7 × 33.6 cm
 cosmic-ray rejection
 shower leakage
correction
Data
acquisition
Flexible hardware
Trigger +
Software filters
The largest area silicon detector in the world!
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LAT ISOC
ISOC Review, 15 February 2006
LAT Prior to Installing the
Anti Coincidence Detector
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LAT ISOC
ISOC Review, 15 February 2006
LAT Data Acquisition System
SIU
SIU
[EPU]
GASU
GASU
[EPU]
PDU
PDU
[EPU]
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LAT ISOC
ISOC Review, 15 February 2006
16 Towers with ACD
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LAT ISOC
ISOC Review, 15 February 2006
GLAST Operations Phases

After the initial on-orbit checkout, verification, and calibrations,
the first year of science operations will be an all-sky survey.
– all parts of the sky observed for ~30 minutes every 3 hours.
– first year data used for detailed instrument characterization,
refinement of the alignment, and key projects (source catalog,
diffuse background models, etc.) needed by the community
– data on transients will be released, with caveats
– repoints for bright bursts and burst alerts enabled
– extraordinary ToO’s supported
– limited first-year guest observer program
– workshops for guest observers on science tools and mission
characteristics for proposal preparation

Observing plan in subsequent years driven by guest observer
proposal selections by peer review. Public data released
through the GLAST Science Support Center (GSSC).
– Currently expect most science to be done in sky survey, but there
will be substantial periods of pointed observations.
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LAT ISOC
ISOC Review, 15 February 2006
The GLAST Sky
GLAST is the next great step beyond EGRET, providing a huge leap in capabilities:
Very large FOV (~20% of sky), factor 4 greater than EGRET
Broadband (4 decades in energy, including unexplored region E > 10 GeV)
Unprecedented PSF for gamma rays (factor > 3 better than EGRET for E>1 GeV)
Large effective area (factor > 5 better than EGRET)
Results in factor > 30-100 improvement in sensitivity
EGRET 3rd Catalog: 271 sources
LAT 1st Catalog: >9000 sources possible
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LAT ISOC
ISOC Review, 15 February 2006
GLAST Gamma-Ray Burst Handling

Upon detection of a GRB, GLAST Observatory can take two levels
of action:
– alerts to the ground
• GBM and LAT issue alerts independently
• Alerts are used by other facilities to provide additional
measurements that help give meaning to the GLAST data (e.g.,
redshifts)
– autonomous repoint to follow burst
• both GBM and LAT can generate a repoint request
• GBM expected to detect more bursts than LAT. However, if LAT
detects a burst, it will probably provide a better localization of the
burst position;
• therefore, GBM repoint request routed through LAT, which either
passes on the GBM request or sends LAT’s position.
– alerts will happen more frequently than repoint requests
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LAT ISOC
ISOC Review, 15 February 2006
LAT Instrument Science Operations Center (ISOC)

The LAT ISOC is organized to:
– Support operation of the Large Area Telescope
– Produce LAT Level 1 and selected Level 2 science data products
 Main Functions:
– LAT command planning and construction
– LAT Instrument health and safety monitoring
– Maintain and modify LAT flight software and the LAT Testbed
– LAT performance verification and optimization
– Process and archive LAT Level 1 and Level 2 data
– Maintain and optimize the software that produces LAT science
data products
– Support the LAT collaboration
 DOE supports the ISOC through SLAC operating funds
– ISOC Operations costs capped by OMB at $5M per year
– Support for GLAST related SLAC scientists at approximately
$2.5M per year
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LAT ISOC
ISOC Review, 15 February 2006
LAT ISOC in the GLAST GDS
Analysis Software
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LAT ISOC
ISOC Review, 15 February 2006
ISOC and the LAT Collaboration
ISOC works closely with the LAT collaboration
ISOC provides data to collaboration during first
year of mission, and beyond
Collaboration scientists provide support to
ISOC for instrument analysis
Joint oversight by LAT Operations Steering
Committee
Steering committee functions
 Guides coordination between ISOC and LAT
Collaboration Science Groups
Sets and reviews high-level policy and
priorities
 Resolves issues as needed
 Membership:
P.F. Michelson
S. Ritz
W.N. Johnson
W.B. Atwood
R. Cameron
Analysis Coordinator (rotating)
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LAT ISOC
ISOC Review, 15 February 2006
ISOC Organization
ISOC
Manager: R. Cameron
Deputy: E. do Couto e Silva
Deputy: R. Dubois
Commanding,
Health and Safety
R. Cameron / J. Thayer
Science Analysis
Systems
R. Dubois
Flight Software
Science Operations
J. Thayer
E. do Couto e Silva / S. Digel
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LAT ISOC
ISOC Review, 15 February 2006
ISOC Team Activities and Responsibilities
Commanding, Health and Safety
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LAT mission planning support
Generate and validate LAT commands
Pass LAT commands to the GSSC
Verify correct commands execution
Receive Level 0 data from the MOC
Log and archive commands and Level 0
data
Monitor LAT health and safety
continuous knowledge of the configuration
of the LAT
Support LAT I&T
– Data transport, archiving, trending
Science Operations
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Characterize, monitor and optimize LAT
Performance at all levels
– individual LAT detectors
– LAT as an integrated particle physics
instrument
– LAT as a high energy gamma ray detector
Coordinate investigation of instrument
anomalies
Coordinate LAT operations scientist program
Coordinate Science data processing
Quick look science/alerts
Standard product generation/delivery
Flight Software Systems
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Develop, test, and maintain LAT flight
software
Develop and maintain software tools for the
development, testing, and documentation of
the operational LAT flight software
Maintain the tools that track LAT
Configuration
Maintain the Dataflow lab and LAT testbed
Maintain and develop documentation
Interface with other ISOC groups to
troubleshoot issues on orbit
Science Analysis Systems
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Moving towards providing all software
development for the LAT ground work
Supports ISOC and LAT collaboration
Support software development environment
and tools
Instrument data processing: reconstruction,
calibration and simulation
High level science tools & Quicklook
Automated processing pipeline machinery
Acquire and coordinate most LAT compute
resources at SLAC: bulk CPU and disk usage
Database and web development
– System tests, Data Monitoring
– Tools used in ISOC day-to-day handling
of downlinks
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LAT ISOC
ISOC Review, 15 February 2006
ISOC Teams in Practice
CHS
SAS
SO
FSW
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LAT ISOC
ISOC Review, 15 February 2006
Pre-launch ISOC Activities
In addition to ISOC development and activities outlined above, the ISOC
budget supports several areas of LAT Integration and Test activity:

LAT I&T at SLAC
– FSW development
– LAT EGSE software (LATTE/LICOS) development
– Science Validation and Calibration (SVAC)
– SAS/Offline processing
 LAT I&T at NRL
– Continued FSW support
– Continued EGSE s/w and h/w support
– Continued SVAC support
– SAS/Offline processing support
 Observatory I&T at GD/Spectrum Astro Space Systems
– ISOC provides some EGSE h/w and s/w
 Pre-launch activity at Titusville/KSC
– TBD, probably similar to ISOC-provided EGSE support at
GD/SASS
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LAT ISOC
ISOC Review, 15 February 2006
Post-launch ISOC Operations Concept
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Manual and automated activities at ISOC
– Manual: mission planning support, command load preparation
– Automated: Health and safety monitoring
– Automated: Receipt, ingest, processing, archiving of Level 0 data
products
ISOC supports the MOC’s weekday, day-time operations
– Operator 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
• Operations Lead and Operations Scientist for anomalies
• Operators for real-time commanding or anomaly support
Duty scientists from collaboration will provide 24 hour support
Weekly mission planning cycle during normal mission
Simple anomaly response requirements for GLAST Flight Ops Team
– Notify the ISOC
– Follow defined contingency procedures
Close cooperation of LAT collaboration needed in first year of mission
(and beyond) to augment ISOC teams
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LAT ISOC
ISOC Review, 15 February 2006
ISOC Data Flows
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LAT ISOC
ISOC Review, 15 February 2006
Expected Instrument Operations
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Data taking
– Continuous, outside SAA
– Few commands needed
Calibration
– Weekly, biweekly and monthly
– A few commands to initiate
Load changes to tables and FSW
– Infrequent
– A few commands and/or file uploads which may be large
Load new tables and files
– Infrequent
– A few commands and/or file uploads which may be large
Perform Diagnostics
– Infrequent
– A few commands and/or file uploads which may be large
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LAT ISOC
ISOC Review, 15 February 2006
Initial Turn-On and Checkout of LAT
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Launch and Early Orbit (L&EO) phase is scheduled for first 60
days after launch
Instrument turn-on will not be executed automatically
– Humans required to check environmental conditions prior
to significant steps
– Must establish correct LAT configuration at each step
Functional checkout of DAQ, ACD, CAL and TKR
Initial calibrations
ISOC will have staff at GLAST Mission Operations Center at
NASA/GSFC during L&EO, but data will also flow to west coast
ISOC for processing
– Processing and analysis of LAT science and calibration
data at SLAC is essential to bring LAT to operational state
– LAT collaboration will work with LAT data via ISOC
resources
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LAT ISOC
ISOC Review, 15 February 2006
LAT Operations Facility at SLAC

LAT Operations Facility
– Funded as SLAC infrastructure project
– Located in the Building 84, Central Lab Annex
– Elements
• Operations Control Room. Being built and configured in
2006, to support pre-launch operations testing.
• Dataflow Lab
– Existing Dataflow Lab houses LAT testbed
– New Dataflow Lab extension in 2007. Provides additional
space for spare detectors and other additional equipment.

ISOC operations staff offices adjacent to Operations Facility in
Central Lab Annex.
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LAT ISOC
ISOC Review, 15 February 2006
LAT Operations Facility at SLAC
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LAT ISOC
ISOC Review, 15 February 2006
ISOC Operations Facility Schedule

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Control room ready at end of 2006
Facility complete in early 2007
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LAT ISOC
ISOC Review, 15 February 2006
GLAST Ground System Schedule
Ken Lehtonen & Howard Dew Code 581
& Ross Cox ASRC Aero
GLAST Ground System / Mission Operations Schedule Version (1/4/06)
Light blue areas indicate modifications.
Yellow indicates changed row headings.
2003
2004
2005
2006
2007
J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D
S/C
PDR
Project ReviewsUNOFFICIAL
S/C CDR
Dry Run
5/5-7
MPDR/NAR
6/3
S/C CDR
5/24-27
MOR
3/15-16
MCDR
9/21-22
PSR
4/12
PER
8/4
8/13
FRR
8/29
4/18
5/1
Observatory I&T
Observatory Milestones
UNOFFICIAL
5/3
.
.
(Estimated at 6 month
Ground System Deliveries
MOC
ICD's GSRD Final Project Plan
intervals)
12/17 2/15
(Draft)
Dev Plan
12/17
GCM = GLAST Contingency MOC
LAT Instrument Science Operations
Center (LISOC)
GLAST Burst Monitor IOC (GIOC)
GLAST Front-End Processor (GFEP)
Rel 1 DPF
9/15
SRD
3/17
H/W Phase 1Peer
3/1 Review
3/2
Data Challenge
#1
2/11
WSC/GFEP
ICD 2/18
MOC Rel 1
3/30
Design Spec
7/30
CDR
5/26
H/W Phase
GSSC
2 1/15
Rel 1
11/15
GBM Rel 1
2/9
GFEP PSR 10/17/05
Draft - 12/5
Ground System Testing
IOC Plan
1/14
Prototyping
F&PS
Test Plan
HW Rqmts Spec
10/1
Dev GFEP
6 OPS GFEP
Rel 1
Procur
Procur. & Integ.
10/1
Final - 9/15
MOC Rel 2
9/30
MOC Rel 3
5/26
GCM
Install
7/31
Rel
GSSC
1.1 H/W Phase
Rel
GSSC
1.2
3 3/1Rel 2 RelGSSC
3
9/29
Rel 3
11/16
Rel 4
3/2
5/4 Rel 5
6/14
10/12
11/16
Data Challenge
#2
3/1
5/11
GSSC
Rel 1
Rel 2
5/31
4/28
CDR
10/30
SW PDR, SRD,
Dev Plan
5/2
GBM Rel 2
9/15
GBM Rel 2.1
11/1
OPS
WSC
11/ 10
GFEP Test
Mini-MOC at
I&T
MOC Rel 4
8/31
11/17
GSSC RelGSSC
GSSC
GSSC
4
Rel 6
Rel 7
Rel 8
Rel 9
10/30
8/16
11/21
11/15
Data Challenge 5/15
1/15
#3
2/19
CTV 3/TBD (7 days)
USN 3/TBD (5 days)
RF COMPAT #1
Ops Concept
Rev 1 Update
12/17
Ops Agrmnt
Draft - 2/1
Ops Agrmnts
Final - 11/21
GRT#4
11/17
GRT#5 GRT#6
7/5
9/6
ETE #2
11/15
Ops Product (e.g. PROC) Dev/Validation
RF COMPAT #2
GRT#7
12/13
MORP F inal
4/15
ETE #1
8/1-2
10/18
Ops Readiness Tests
GRT#3
12/14
MORP Prelim
2/28
End-to-End Tests
MOC Rel 5
11/30
GSSC
Rel 10
5/9/08
OPS
I&T
2/13
CTV 9/7-14 (7 days)
USN 9/15-20 (5 days)
GRT#1 GRT#2
4/13
6/27
Msn Ops
Read. Plan
(MORP)
Draft - 11/1
Ground
System Freeze
H/W Phase 2 1/15
Test Rqmts DB
10/1
Ground Readiness Tests
On-orbit
Accept
LAUNCH Review
8/31/07 10/31
BAP Delivery GBM Rel 3
2/22
5/14
RF Compatibility Tests
Mission Operations
FOR
6/30
PSSSDR
#1
PSS #2
8/18-19
SRR
7/22
Ground System Reviews
Ship to
KSC
4/19
5/10
Bus I&T
ETE #5
3/28
ETE #3 ETE #4
1/15
3/15
ETE #6
5/15
11/1
M S #1 M S #2
4/12
3/30
Mission Simulations
Launch Rehearsals
S/C CDR - 1 Month
4/24
CDRL
J Prelim
A S
O 23NSN-ICD
D JInputs
F M A
J F M A M J
2003
12/24
M J J A S O N D
2004
S/C CDR + 7 Months
J Final
F MCDRL
A 23
MSN-ICD
J J Inputs
A S
2005
LRR
8/30
LSRR
8/21
LR #1
8/3
M S #3
7/30
LR #2
8/24
O N D J F M A M J J A S O N D J F M A M J J A S O N D
2006
2007
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LAT ISOC
ISOC Review, 15 February 2006
Backup Slides
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LAT ISOC
ISOC Review, 15 February 2006
Observatory Science Requirements (I)
33
LAT ISOC
ISOC Review, 15 February 2006
Observatory Science Requirements (II)
34
LAT ISOC
ISOC Review, 15 February 2006
Observatory Science Requirements (III)
35