GLAST LAT Project
Gamma-ray Large
Area Space
Telescope
GSFC Monthly, 15 Dec 2003
GLAST Large Area Telescope:
LAT System Engineering
Pat Hascall
SLAC
System Engineering
LAT System Engineering
1
GLAST LAT Project
GSFC Monthly, 15 Dec 2003
Topics
•
•
•
•
•
•
•
Action Item Status
Technical Baseline Management
Requirements Management and Verification Planning
Interface Control Documentation
RFA Closure
Key Metrics
Risk Management
LAT System Engineering
2
GLAST LAT Project
GSFC Monthly, 15 Dec 2003
Monthly Action Item Status
GSFC Monthly Review Notes/Actions
Action Item ID
7-30-03-006
7-30-03-008
7-30-03-009
Actionee
Description
Status
Haller
For TEM/TEM PS to be provided to CAL
Qual/Accept program; provides a
OPEN: ECD 27 August; ECD 29
specific list of differences from flight
October - Further definition required,
(hardware/software/performance),
plan in work.
include any constraints for use (T/V,
EMC…..)
Jerry Clinton
Define and maintain the production
readiness/execution plan to include
vendor selection and associated
schedule to ensure unit availability dates
are met
OPEN: Draft production plan
completed & provided to GSFC.
Refinement required as vendors are
selected. Update provided early
December. Next update ECD:mid
January.
Dick Horn
Establish subsystem metrics to ensure
critical design elements are closing (e.g.
drawings) and fabrication issues are
monitored for closure and adverse
trends (e.g. NCRs), phase in as possible
Closed: Initial drawings and process
status in place. Power & mass
updates complete, NCR status and
plans for future metrics presented by
D. Marsh
LAT System Engineering
3
GLAST LAT Project
GSFC Monthly, 15 Dec 2003
Drawing Release Status
•
•
•
Drawing preparations at SLAC matched needs for November (still need
a few status updates to be sure)
Drawing release did not keep pace
– Tracker team put in 30 drawings in November that are still not
released
• Due in part to vib test results – have broken free drawings
unaffected by that test
• Have instituted a better tracking system to provide better
visibility into where drawings are in the release cycle
– Mechanical, Cal and Electrical on track
– ACD report is incomplete but progress is apparently 46 drawings
behind release plan
Additional drawings identified
– Four Tracker drawings
– 14 Outline drawings needed by Integration
• Intermediate link between subsystem models and LAT model
– Three harness drawings
LAT System Engineering
4
GLAST LAT Project
GSFC Monthly, 15 Dec 2003
Planned Drawing Release
Planned Drawing Release
Actuals
Planned Total
Subsystem Released Drawing Count
600
500
400
300
200
100
0
Oct-03
Nov-03
LAT System Engineering
Jan-04
Mar-04
Apr-04
Jun-04
5
GLAST LAT Project
GSFC Monthly, 15 Dec 2003
Issues
No.
2
Title/Description
X-lat to electronics
thermal interface not
complete
3
Technical baseline
4
Tracker/TEM/TEMPS
flex cable layouts
5
EMI/EMC design
8/9
GTRC TOT timeouts,
GTRC extra clock
delay
LAT System Engineering
Description/Status
Design nearly complete, still a few
issues to work out. Peer review
expected by end of October (Nov
5)
Drawing Tree completion by end
of Oct. All drawings under CM
prior to flight build
Conceptual redesign is complete,
need to update drawings. Peer
review on 28 Oct.
Following items will be
implemented to mitigate
EMI/EMC issues:
E Ni plating on metal to metal
surfaces,
Cal to implement presented design
mods
EMI gaskets per discussions with
Fred,
Venting unchanged
Design mods in place,
implementation audit to follow
Cause understood. Fix would
require GTRC redesign or correct
in TEM. Plan presented at 29 Oct
03 Monthly Review. Revisit when
chip is complete
Due Date
Closed, Peer
review held 5
Nov
Actionee
M. Nordby
19 Dec 03
P. Hascall
Closed, Peer
review held
M. Nordby
Closed
F. Blanchette
January
R. Johnson
6
GLAST LAT Project
GSFC Monthly, 15 Dec 2003
Issues (Continued)
No.
10
Title/Description
Tracker EM program
completion
11
ACD TDA flexure / fiber
interference
12
ACD – LAT interface
definition not complete
(blanket attachment,
grounding, cable tie downs,
optical survey mounts)
LAT System Engineering
Description/Status
Mid Nov Vib test results
under evaluation (loss of
torque in bolts holding
flexures to grid
simulator) TV test
planning in work.
Rerouted fibers, tapered
flexures and moved some
flexures. Performing final
analysis, dawings in
review. –Presented in
Engineering review in
November
Cable tie downs to be
addressed by the LAT.
Remainder in work at low
priority. (Will be broken
into several issues as
Martin plans effort) Have
new engr assigned to
task
Due Date
19 Dec 03
Actionee
R. Johnson
Closed
D. Thompson
19 Dec for M. Nordby
plan
7
GLAST LAT Project
GSFC Monthly, 15 Dec 2003
Issues (Continued)
No.
13
Title/Description
Tracker MCM attachment and
wire bonding
15
Radiator integration
clearances not sufficient
Fly away instrumentation not
finalized
16
17
New coupled loads results
may create negative margins
LAT System Engineering
Description/Status
Test boards from
preproduction group sent
to Italy for inspection to
verify solution
Radiator integration
approach in process
Locations in the
instrumentation plan must
be finalized to be able to
assess impacts to Tracker
Grid and DAQ.
Thermistors have been
defined, internal accel
counts bounded, strain
guages are only on qual
grid. Positions in work.
Analysis complete.
Results positive – critical
loads went down. LAT
Structural Analysis
Report in work.
Environmental Spec to
be updated
Due Date
Jan 04
Actionee
R. Johnson
19 Dec
M. Nordby
16 Jan 04
Hascall
30 Jan 04
J. Ku
8
GLAST LAT Project
GSFC Monthly, 15 Dec 2003
Issues (Continued)
No.
18
Title/Description
EMI/EMC requirements
and test
19
ACD channelization (+X
and –X faces)
20
PMT exposure to
helium
LAT System Engineering
Description/Status
System analysis tool under
development, requires
subsystems help. Will result in
test requirements documented in
the environmental spec
ACD right FREE card (on the
+X and –X) channel numbers are
not consistent with the ICD.
Change proposed, reviewed in
weekly engineering meeting on
Nov 4 04. CR in work, work
authorized as an emergency
change
The heat pipe pinch off tubes
are close to the BEA, with the
resulting potential for PMT
helium exposure. Have leak
rates from vendor, reviewing
Due Date
9 Jan 04
Actionee
F. Blanchette
Closed
pending
CR sign off
Hascall
16 Jan 03
Nordby
9
GLAST LAT Project
GSFC Monthly, 15 Dec 2003
Requirements & Performance Verification
Progress
Test Data Requirements
– New direction to add appendix to LAT-MD-00408 for each
subsystem defining End item data packages (12/10 F to F)
Test Planning
– Post CDR LAT-MD-00408 out for signatures
• Highlights include:
–
–
–
–
Changes TKR & CAL to Proto Flight Programs
Updated EMI section
New Assy & Test Flow
Added strength Testing
LAT System Engineering
10
GLAST LAT Project
GSFC Monthly, 15 Dec 2003
Updated LAT Performance Verification Plan
•
•
•
Additions
– Added section on plan for the test plans
– Updated and re-formatted reference documents
– Added section on Strength Testing
Deletions
– Removed reference to an ESD compatibility test
– Removed Appendix-A, example Test procedures
Changes
– Updated LAT Assembly and Test Flow
– Updated EMI/EMC Section to reflect latest post CDR requirements
– Updated document release matrix
– Updated section on Test Data Packages
– Changed Tracker to a Proto Flight Program
– Changed Calorimeter to a Proto Flight Program
– Provided details on alignment and Survey
– Updated LAT Thermal Vacuum cycle plot (from CDR)
LAT System Engineering
11
GLAST LAT Project
GSFC Monthly, 15 Dec 2003
Test Plan Schedules
•
•
•
•
•
•
•
•
•
LAT I&T - Assembly Plan – 12/19/03
LAT Comprehensive Performance Plan- 6/04
LAT Limited Performance Plan - 6/04
LAT Operational Performance Tests - 3/04
LAT Instrumentation Plan - Update 1/16/04
LAT Survey Plan – 1/16/04
LAT Dynamics Test Plan – First Release 12/19/03, Final 3/04
LAT Thermal Test Plan - First Release 1/16/04, Final 3/04
LAT EMI/EMC Test Plan - First Release 3/04
LAT System Engineering
12
GLAST LAT Project
GSFC Monthly, 15 Dec 2003
Interface Management
LAT System Engineering
13
GLAST LAT Project
GSFC Monthly, 15 Dec 2003
LAT-SC Interface – Open Issues
System
Subject
Data
Digital signal grounding
Mech
LAT Radiator I/F pad size
Closure Path
Need Date
Promise Date
Comments
Spectrum performing
observatory
grounding analysis.
6/1/2004
Done
GSFC preparing
CCR.
10/15/2003
In Closure
Is in 00040 (LAT document). Need a CCR to
put this into the IRD. CCR 207 in review.
ICN-37 signed.
Mech
LAT Connector Locations
LAT Provide
10/15/2003
11/30/2003
Need X, Y and Z locations with connector
orientations. In process - New EMI bulkheads
installed on LAT mock-up. Checking cable
routing and mechanical interfernces. Related
to next two actions.
Mech
Harness Routing on LAT
LAT Provide
10/15/2003
11/30/2003
Need pictures for ICD. Same as above.
Mech
Harness Support on LAT
LAT Provide
10/15/2003
11/30/2003
Need definition of support hardware. Same as
above.
Therm
LAT Thermal Model Size
GPO Agree on
Model, update IRD
10/15/2003
In Closure
Update IRD to clean up compliance. Delivery to
GSFC finished. Still checking model at GSFC.
Elec
LAT current transients
LAT Provide
10/15/2003
2/1/2004
Elec
LAT Impedence
LAT Provide
10/15/2003
2/1/2004
Elec
42 V Input Voltage
GSFC to Respond
ASAP
Waiting
Elec
LAT startup plan (??)
LAT Provide
10/15/2003
Waiting
LAT System Engineering
Spectrum delivered PRU measuremnts 12-1-03.
LAT to perform measurments on EM units.
Plan to sign up to measured values and close
then.
Spectrum delivered PRU measuremnts 12-1-03.
LAT to perform measurments on EM units.
Plan to sign up to measured values and close
then.
LAT submitted request to change IRD.
Awaiting GSFC response.
GSFC/SAI to define this.
14
GLAST LAT Project
GSFC Monthly, 15 Dec 2003
ICN’s
• LAT signed this month
–
–
–
–
–
ICN-9 Reduce the High Speed Serial Science Data Rate (11-11-03)
ICN-17 LAT Orientation during TVAC Testing (11-11-03)
ICN-25 Add SC RT to 1553 Protocol Document (11-11-03)
ICN-37 Add Digital Grounds to Connector Pin-outs (11-21-03)
ICN-36 LAT-SC Mechanical Interface (11-25-03)
• Currently under signature review
– ICN-39 PRU Over-Voltage Limit
• Currently in draft or revision
– ICN-33 LAT Analog RTD Part Type
LAT System Engineering
15
GLAST LAT Project
GSFC Monthly, 15 Dec 2003
Interface Documentation Status
Document
LAT-SC Interface Control Document (Spectrum Astro Managed Document)
1196 EI-Y46311-000
1553 Bus Potocol Document
1196 EI-S46310-000
GBM-LAT Interface Control Document
433-ICD-0001
Calorimeter
LAT-DS-00233-6: CAL-LAT Interface Definition Drawing
LAT-SS-00238-4: CAL-LAT Mech, Therm, Elec Interface Control Document
ACD
LAT-DS-00309-3: ACD-LAT Interface Definition Drawing
LAT-SS-00363-5: ACD-LAT Mech, Therm, Elec Interface Control Document
Tracker
LAT-DS-00851-1: TKR-LAT Interface Definition Drawing
LAT-SS-00138-5: TKR-LAT Mech, Therm Interface Control Document
LAT-SS-00176-2: TKR-LAT Elec Interface Control Document
Electronics
LAT-DS-01630-1: Electronics-LAT Interface Definition Drawing
LAT-SS-01794-1: Elec-LAT Mech, Therm, Elec Interface Control Document
SAS
LAT-SS-02365-1: SAS-LAT Interface Control Document
LAT System Engineering
Status
Rev B in sign-off
Released 25 Apr 03
In sign-off
Released 6 May 03
Released 13 Mar 03
Released 22 Apr 03
Rev 6 update in-process
Second draft in-process
Released 14 Apr 03
Released 27 Jan 03
First draft review complete
Second draft in-process
First draft in-process
16
GLAST LAT Project
GSFC Monthly, 15 Dec 2003
Working CDRL Delivery List
NO.
ITEM
PURPOSE
FROM
TO
MATURITY
Promise
DATE
Feb. ‘04
Nov. ‘05
Dec. ‘05
Prelim. MCDR- 2
months
Dec. ‘05
Items 2 & 3
previously combined
1.
LAT Safety Input to Launch Vehicle
Documentation
Meet Range Safety Requirements
LAT
SAI
Preliminary
FINAL
2.
Spacecraft I & T Support
Obs. Development
LAT
SAI
N/A
3.
Launch Vehicle I & T Support
LAT
SAI/LV
N/A
4.
Support Development of S/C
I & T Procedures
Obs. Testing
LAT
SAI
N/A
5.
LAT Delivery
Obs. I & T
LAT
SAI
FM
Dec ‘05
6.
LAT GSE (Mechanical and Electrical)
Obs. I & T
LAT
SAI
FM
Dec ‘05
7.
Flight Connectors
Obs. I & T
SAI
LAT
Test
FM
8.
LAT Thermal Model
- Full TMM
- Launch Vehicle Model
(200Nodes)
- TMM FEM Mapping
STOP & Observatory TA
Obs. Case Studies & LV Delivery
LAT
LAT
LAT
SAI
SAI
SAI
CDR
CDR
Oct ‘03
Mar ‘06
Support LAT T/M Distortion/STOP
Obs. Strength (10.03)
CLA
LAT
LAT
LAT
GSFC
SAI
SAI
CDR
CDR
CDR+
Dec ‘03
Oct. 30
Dec ‘03
LAT
SAI
CDR
Dec ‘03
LAT
SAI
CDR
Dec ‘03
CDR
Dec ‘05
9.
LAT FEM (Full)
Nov. ‘05
Oct ‘03
11. LAT Mass Properties Information
ICD Documentation (harness routing,
connectors, etc)
SAI to build mass simulators for S/C
structural qualification
12
Identify sources of radiation for range
LAT
SAI
13. LAT Instrument/Spacecraft Simulator
Obs. Development
LAT
SAI
FINAL
Apr ‘04
14. Spacecraft/LAT Instrument Simulator
LAT Development DIIS
SIIS
SAI
LAT
Preliminary
FINAL
Jul ‘03
Dec ‘03
15. LAT Input to ICD
ICD Development
LAT
SAI
Updates
16. S/C Flexures (Flight Like)
LAT Testing Model
Hardware
SAI
LAT
Test
17. Drill Template
LAT
SAI
LAT
18. S/C Acoustic Simulator
LAT Model (FEM)
Hardware
SAI
LAT
LAT Testing
LAT
SAI
10. LAT STEP
LAT Radiation Source Survey
Ground Ops Plan (Hazardous &
19. Safety Critical Operations)
LAT System Engineering
STATUS/NOTES
Received first
delivery. Awaiting
second delivery.
Oct ’03 – Done
Dec ’03 delivery on
track
Oct ’03 - Done
Dec ’03 delivery on
track
Work in process
November mass
report released.
Rev B in review
10/30/03
3/04
Flight Flexures
remain at SAI
1/04
Preliminary
Final
12/04
4/05
7/03
2/04
17
GLAST LAT Project
GSFC Monthly, 15 Dec 2003
RFA Closure
• Coordinated plan of attack in place –Horn/Graf/Hascall/Melton
– 37 CDR RFAs total, submitted 21 answers, have 5 draft
answers
• Preparations for MRRs are driving RFA closure priorities
• Current status of all RFA’s on SE website
LAT System Engineering
18
GLAST LAT Project
GSFC Monthly, 15 Dec 2003
Key Design Metrics
LAT System Engineering
19
GLAST LAT Project
GSFC Monthly, 15 Dec 2003
LAT Mass Status
LAT System Engineering
20
GLAST LAT Project
GSFC Monthly, 15 Dec 2003
November 03 LAT Power Status (Proposed)
• Operational Power
Item
10-Nov-03 Estimate
(Watts)
ACD
9.4
2.3
3.9
3.2
10.5
152.4
1.5
0.0
150.9
153.0
64.9
0.0
0.0
64.9
65.0
318.6
44.5
87.3
186.8
327.5
20.4
20.4
0.0
0.0
35.0
Instrument Total
565.7
68.7
91.1
405.8
591.0
Instrument Allocation
650.0
% Reserve
14.9%
Calorimeter
Trigger & Data Flow
Grid/thermal
CALC
(Watts)
MEAS
(Watts)
ALLOC.
(Watts)
PARA - Best Estimate based on
conceptual design parameters
CALC - Estimate based on
Calculated power from detailed
design documentation
MEAS - Actual power
measurements of components
Goals estimated using guidelines
given in ANSI/AIAA G-020-1992
"Estimating and Budgeting Weight
and Power Contingencies for Space
Craft Systems"
LAT System Engineering
PDR Reserve Was 15.2%
CDR Reserve Was 13.4%
Goal for PSRR Reserve > 5%
LAT Power
700
650
Power - Watts
Tracker
PARA
(Watts)
600
550
PDR
7/30/02
I
500
450
CDR
5/1/03
I
PSRR
9/05
I
400
Jan-99
Jan-00
Jan-01
Jan-02
Jan-03
Jan-04
Jan-05
Jan-06
21
GLAST LAT Project
GSFC Monthly, 15 Dec 2003
November 03 LAT Power Status (Continued)
• Survival Power
Component
On-Orbit Average Power Total1
Regulated VCHP Power Total
Unregulated Passive Survival Power
Current
Alloc.
278.00
58.00
220.00
PARA
0.00
0.00
0.00
Subsystem Power Estimates (W)
CALC
MEAS
Total
230.40
0.00
230.40
48.40
0.00
48.40
182.00
0.00
182.00
Margin
20.7%
19.8%
20.9%
1
Power estimates reflect the LAT steady state orbit average. Numbers do not reflect transition into or out of survival mode, i.e. early
orbit operations.
• Changes to power budget
– Updated Trigger and Data Flow
• Included design presented during Power Supply Peer
Review (removed linear regulators)
• Incorporated measurements in power supply
efficiencies
– Survival power updated to reflect selected heaters
LAT System Engineering
22
GLAST LAT Project
GSFC Monthly, 15 Dec 2003
FSW Resource Usage Current Estimates
Resource
Total Available
Anticipated
Usage
Margin
Factor
EPU Boot PROM
256 kB
128 kB
2
SIU Boot PROM
256 kB
128 kB
2
EPU EEPROM
6 MB
1.5 MB
4
SIU EEPROM
6 MB
1.5-2.5 MB
3
EPU CPU cycles
200% in 2 EPUs
30%
>6
SIU CPU cycles
100% in 1 SIU
25%
4
EPU memory
128 MB
16-32 MB
4-8
SIU memory
128 MB
< 16 MB
8
Bandwidth – instrument to EPU
45 MB/sec
10 MB/sec
4.5
Bandwidth – EBM to CPU
20 MB/sec
5 MB/sec
4
Bandwidth – CPU to EBM
2.5 MB/sec
20 kB/sec
125
Bandwidth – EBM to SSR
5 MB/sec
40 kB/sec
125
LAT System Engineering
23
GLAST LAT Project
GSFC Monthly, 15 Dec 2003
Key Science Performance Metrics
LAT System Engineering
24
GLAST LAT Project
GSFC Monthly, 15 Dec 2003
Risk Management
LAT System Engineering
25
GLAST LAT Project
GSFC Monthly, 15 Dec 2003
Risk Management Activity
• No new issues
LAT System Engineering
26
GLAST LAT Project
GSFC Monthly, 15 Dec 2003
Top risks to cost
ID #
Proj
Mgt 005
Proj
Mgt 006
Risk
Rank
Moderate
Moderate
Risk Description
Parts and vendor orders have
not been completed therefore
flight production cost may
exceed projection
Critical skilled positions (senior
personnel) required to execute
project remain open, potential
impact to cost and schedule if
not closed in short term
Risk Mitigation
Status
•Manufacturing engineer added
to expedite minimum cost
closure
•Clarification and purchase
package review to ensure
accurate bids
• Processes in place
•Management team has
identified critical skill needs
• Identify skilled personnel
within Collaboration
environment
• Added SLAC Site Rep in
Italy
•Remaining vendor
selections by 11/03
• Added Scientist to
Tracker Team & Proj Eng
•Continuing to expand
FSW support
•Identified additional QA
support requirements
•Added additional
Structural analyst support
•Added Design Eng
Support
LAT System Engineering
27
GLAST LAT Project
GSFC Monthly, 15 Dec 2003
Top risks to schedule
ID #
Proj
Mgt 003
Risk
Rank
Risk Description
Completion of Tracker subsystem
qualification program delayed due
to EM closure or MCM electronics
Moderate
ASIC’s fail to meet requirements;
results in schedule impact
Proj
Mgt 002
Moderate
Risk Mitigation
Status
• Manufacturing Eng assigned to close
MCM issues
• Increased team integration with
Italian partners
• GSFC audit/support to Tracker EM
closure
• 50 Unit Pre-production
run established with
Teledyne, ECD: Jan 04
•Focused review & test. Margin for reruns protected where possible
•Individual risks Identified by
subsystem
• DAQ ASIC’s flight
ready, continued testing
•Engineer (Dave Rich)
added to drive closure
•Added Design Eng
• Tracker GTRC error
found, plan in place
• Cal/ACD ASIC’s
continued testing
Proj
Mgt 004
SE-007
Moderate
TEM Power supply final design is
delayed, final implementation may
exceed current schedule
•Key focus item identified for DAQ
• Design peer review 9/03
• Basing approach on flight proven
designs where possible
• Peer review completed
9/22/03
Critical component failure post LAT
integration requiring de-integration
impacting cost & schedule
•Extensive use of EM test bed to
support flight H/W & S/W
development
•Thorough qualification and
acceptance tests
•Pre planned I&T actions for deintegration
•LAT Assembly plan
under update to
incorporate EM1
lessons learned,ECD:
Jan 04
Moderate
LAT System Engineering
• Re-baselined, tight
schedule for EGSE
28
GLAST LAT Project
GSFC Monthly, 15 Dec 2003
3-Month Milestones
• Update the LAT-MD-00408 LATPVP – Released for review 12 Dec
• Complete FMEA – GSFC picking up task, bottleneck is transfer of
work in process
• Complete Spacecraft ICD Rev 2 release review – 19 Dec
• Close remaining Internal ICD TBX’s - Complete
• Update System Metrics – Electrical updated this month, next mass
update in Feb
• Complete X-LAT Review –Completed
• Complete CIDL update – Draft by 19 Dec
• Close all open RFAs – October->December->???
• LAT I&T Assembly Sequence – 19 December
• Draft Dynamics Plan – 19 December
• LAT Survey Plan – 16 Jan 04
• LAT Instrumentation Plan – 16 Jan 04
LAT System Engineering
29