glast lat project – cost and schedule reviewnovember 3, 2004 anticoincidence detector 1 glast...

GLAST LAT Project – Cost and Schedule Review November 3, 2004

AntiCoincidence Detector 1

GLAST Large Area Telescope:GLAST Large Area Telescope:Cost/Schedule ReviewNovember 3, 2004AntiCoincidence Detector (ACD) Subsystem WBS: 4.1.6

David J. ThompsonThomas E. JohnsonNASA Goddard Space Flight CenterSubsystem Manager/Instrument Manager

[email protected]@nasa.gov

Gamma-ray Large Gamma-ray Large Area Space Area Space TelescopeTelescope



Significant AccomplishmentsSignificant Accomplishments

• Started flight PMT assembly. 16 units are completed, 10 are being coated, 20 additional units beginning assembly.

• Completed vibration testing of the Spare/Qual Electronics Chassis.

• Installed fiber ribbons on the flight structure.• Successfully completed all mechanical qualification testing of

the new PMT mounting design.• Completed Spare/Qual Electronics Chassis functional testing.• Made preparations to go to EMI testing.• Received 36 new PMTs from Hamamatsu.• Completed the assembly and functional testing of all (4)

single row Electronic Chassis (minus the PMTs)



Recent Accomplishments - Electronic Component Recent Accomplishments - Electronic Component StatusStatus

ITEM Quantity Required

Flight (Spare)

Assembly Complete

Functional Testing

Conformal Coating

Thermal Testing

Ready for next assembly

Front End Electronics Boards

12

(4)

16 16 16 16 16

High Voltage Bias Supply 24

(6)

30 30 30 30 30

Photomultiplier Tube Assembly

196

(40)

16 10 0 10 0



Fabrication, Assembly and Testing statusFabrication, Assembly and Testing status

Blanket Stand-off

Flexure

Doubler

Base Electronics Assembly (BEA) From next page

Fiber ribbon detectors (8)

Composite Shell Assembly (1)

Detector assemblies - TDA - (4 basic types, 89 needed total)

Detector Flexures (366+20 spares)

ACD Assembly (1)

Tile Shell Assembly –TSA (1)

STATUS KEY

In Fabrication or Ordered

Received

In assembly

Assembled

Tested

PrototypedClear fiber cables (130)

Number needed in parenthesis

130

6

12

All 89 + spares

All

All

45

1

8

8

360

1

360, All

130 (All)

88

8

8

1



Fabrication, Assembly and Testing statusFabrication, Assembly and Testing status

Base Electronics Assembly (1) Electronics Chassis (8) (4 double + 4 single)

Base Frame Assembly (1)

– in and assembled

Photomultiplier Tube rails (8 + 2 spares) – All in

Power distribution board (8+2 spares) – All in

Chassis and connector frames (8) – All in

Connectors (32) – All in

1

1

1

1

1

1

1

1

1

1



TSA I&TTSA I&T

• Fiber Ribbon Installation Complete– Resolved issues with overall length

(they were too long) and supporting the ribbons (they sagged)

• All 25 TOP TDAs INSTALLED and GAPS MEASURED

– Data Assessment Showed Some Vertical Gaps Too Large And Some Too Small

• Large Gaps Affect ACD Performance

• Small Gaps Could Lead To Tiles Interference During Vibration Environments

– Mechanical, Science And Systems Teams Met And Agreed To A Plan For Accepting ‘Predicted’ Final Gaps

• Reduced Minimum Allowable Gap From .035” To .024”

• Allowed Largest Gaps at Outer Tile Locations

– FINAL GAP PLAN ESTABLISHED• FINAL INSTALLATION OF TDAs IS

UNDERWAY.

GLAST ACD I&T AETD Monthly 11-01-04

7

InitialTDA/TSA I&T in B7

ACD SubsystemEfficiency

Verification test(include rotate

ACD 90 degree)

EMI/EMC Test

Pre-shipReview (PSR)

Vibration Test

Thermal Balance/Thermal-Vac

Test

Mass Properties ACD ship to SLAC

Pre-EnvironmentalReview (PER)

Acoustic Test

Post-shipCheckout &

Full Functional Test at SLAC

Install & test 1st & 2nd flightChassis onto

ACD

Qual Electronics

ChassisEnvironmental

Test

1st flight chassis

Environmental Acceptance

Test

The remaining Seven Flight

Chassis Environmental

Acceptance tests

10/4 – 11/30 11/25 – 12/7 12/2 – 1/11

ACD FullFunctional

Test

Install ThermalBlanket &

MMS

2/10/05

Assemble last 2 rows of

TDAs & WSF (124-130, 224-230, 324-330, 424-430)

onto TSA

ACD Integrationcomplete

12/29/04 – 1/14/05

1/14/05 – 1/25/05

6/10 – 11/19 12/7 – 12/13

Install & test remaining six

flightChassis onto

ACD

12/14 – 1/13

1/14/051/25/05 – 1/27/051/27/05 – 2/10/05

2/11/05 – 2/23/052/23/05 – 3/4/05

3/4/05 –3/10/05 3/10/05 – 4/7/05 4/7/05 – 4/8/05 4/11/05

4/12/05-4/19/05(was 3/26/05 – 4/2/05) 4/19/05 – 5/17/05

I&T FlowI&T Flow



Near Term MilestonesNear Term MilestonesMilestone Description Date New Date Status/Notes

Complete PMT AssemblyJanuary,

2004

11/05/04 First group completed mid-October. See back up material for more information on PMT issue

Complete Qualification Unit Electronics Chassis Assembly

5/20/0410/1/04 COMPLETED

Complete Flight Mechanical Drawings

September12/1/04 One assembly drawings remains. Designer has been

focused on problem resolution, revisions, and EOs.

Complete installation of 25 top TDAs 10/15/0411/10/04 Initial installation and measurement verification

complete. Final installation underway.

Complete vibration testing of Spare/Qual Electronics Chassis

10/8/04COMPLETE

Complete qualification testing of new PMT mounting design

10/15/04COMPLETED ON 10/26

EMI Testing of Qual/Flight Spare Electronics Chassis

11/29/04Continuing to work on defining requirements that can be tested effectively and efficiently.

Complete environmental and functional testing of first 10 flight PMTs

11/10/04PMTs in conformal coating.

Complete 34 PMTs for first dual row Electronic Chassis

11/19/04

Thermal vacuum test Qual/Flight Spare Electronic Chassis using fully functional EGSE

12/15/04



InterdependenciesInterdependencies

1. EGSE/G3 – Ongoing development with I&T and Electronics groups. – LAT team to arrive at Goddard tomorrow.

2. ICD, IDD, etc – Rich Bielawski is helping track a set of needed changes.– Another IDD (LAT-DS-00309) update has been sent to us for

review. It is currently being reviewed by the mechanical team.



Issues, Concerns, Documentation, & Qual ProgramIssues, Concerns, Documentation, & Qual Program

• Issues– PMTs– EGSE/Electronics Chassis testing

• Concerns– EGSE/Electronics Chassis testing– PMTs– Numerous “minor” technical issues causing schedule and cost

concerns.• Documentation

– Recent “upgrades” to the CM system have caused several issues. This comes at an especially bad time since we have an ISO audit on November 19.

– Status of PR/PFRs– 88 PR’s Closed– 2 PFR’s Closed– 10 PR’s Open– 6 PFR’s Open (1 black, 3 yellow, 2 red)



ACD Schedule VariancesACD Schedule Variances

• 4.1.6 – ACD Subsystem (-$574K cum, -$176 current)• 4.1.6.1 – Management/Science/Systems (-$28K cum, -$10K

current) – LOE tasks scheduled incorrectly in PMCS• 4.1.6.2 – Safety and Mission Assurance (-$37K cum, -$23K

current) – LOE tasks scheduled incorrectly in PMCS• 4.1.6.3 - TSA Schedule Variances ($0K cum, $1K current)• 4.1.6.4 BEA Schedule Variances (-$239K cum, -$30K current)

– All variance is due to the PMTs.• 4.1.6.7 ACD I&T (-$243K cum, -$114K current)

– Technical issues have delayed progress. PMCS schedule has the ACD in TVAC this month. This will continue to get worse, unless rebaseline or CR action is taken.

• 4.1.6.B GSE (-$23K cum, $0K current)– ($23K) – Shipping container work being pushed out to

reduce manpower.



ACD Cost VariancesACD Cost Variances

• 4.1.6 ACD (-$42K cum, $93K current period)• 4.1.6.1 ACD Project Management/Sys Eng/Science (+$213K

cum, +$24K current period)– Science support lower than planned. This is one area that

has been identified as needing additional support in the form of a Grad student.

• 4.1.6.2 Safety and Mission Assurance (-$81K cum, -$69K current period)– (-$44K) - Materials support on the PMT anomaly was

assessed to 4.1.6.2 instead of 4.1.6.4• 4.1.6.3 Tile Shell Assembly (-$122K cum, -$70K current period)

– (-$76K) - Design and analysis manpower– (-$46K) - Fabrication charge backs higher than planned



ACD Cost VariancesACD Cost Variances

• 4.1.6.4 Base Electronics Assembly (-$92K cum, $197K current month)– CCB action corrected majority of cost variance this month– (-$44K) - SLAC ASIC charges.

• 4.1.6.5 MS/TB (+$35K cum, +$5K current month)• 4.1.6.6 ACD Mech Qual and Cal Unit (-$33K cum, -$2K current

month)• 4.1.6.7 I&T (-$66K cum, -$17K current month)

– Have not received credit for the amount of work done.• 4.1.6.B Ground Support Equipment (+$104K cum, +$25K

current month)– (+$38K) – Labor. Costs lagging on mechanical design and

EGSE support.– (+$66K) – Materials. Not billed for work completed



Threats to Schedule and CostThreats to Schedule and Cost

1. GASU/G3 EGSE

2. PMT Assembly

3. Electronics assembly and test

4. Minor Technical Issues that require manpower and time to resolve.

glast lat project – cost and schedule reviewnovember 3, 2004 anticoincidence detector 1 glast...

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