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GLAST Large Area Telescope: Cost/Schedule Review November 3, 2004 PowerPoint PPT Presentation


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Gamma-ray Large Area Space Telescope. GLAST Large Area Telescope: Cost/Schedule Review November 3, 2004 AntiCoincidence Detector (ACD) Subsystem WBS: 4.1.6 David J. Thompson Thomas E. Johnson NASA Goddard Space Flight Center Subsystem Manager/Instrument Manager [email protected]

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GLAST Large Area Telescope: Cost/Schedule Review November 3, 2004

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Glast large area telescope cost schedule review november 3 2004

Gamma-ray Large Area Space Telescope

GLAST Large Area Telescope:

Cost/Schedule Review

November 3, 2004

AntiCoincidence Detector (ACD) Subsystem

WBS: 4.1.6

David J. Thompson

Thomas E. Johnson

NASA Goddard Space Flight Center

Subsystem Manager/Instrument Manager

[email protected]

[email protected]


Significant accomplishments

Significant 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 status

Recent Accomplishments - Electronic Component Status


Fabrication assembly and testing status

Fabrication, Assembly and Testing status

Number needed in parenthesis

STATUS KEY

6

Prototyped

130

Clear fiber cables (130)

In Fabrication or Ordered

130 (All)

Received

In assembly

12

All 89 + spares

All

All

45

Assembled

Tested

ACD Assembly (1)

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

1

8

8

8

8

Tile Shell Assembly –TSA (1)

8

Fiber ribbon detectors (8)

8

360

360, All

1

1

Detector Flexures (366+20 spares)

Base Electronics Assembly (BEA) From next page

Composite Shell Assembly (1)


Fabrication assembly and testing status1

Fabrication, Assembly and Testing status

1

1

1

1

1

1

1

1

1

1

Base Electronics Assembly (1)

Electronics Chassis (8) (4 double + 4 single)

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

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

Base Frame Assembly (1)

– in and assembled

Chassis and connector frames (8) – All in

Connectors (32) – All in


Tsa i t

TSA 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.


I t flow

I&T Flow

10/4 – 11/30

11/25 – 12/7

12/2 – 1/11

Qual

Electronics

Chassis

Environmental

Test

1st flight

chassis

Environmental

Acceptance

Test

The remaining

Seven Flight

Chassis

Environmental

Acceptance tests

12/29/04 – 1/14/05

6/10 – 11/19

12/14 – 1/13

12/7 – 12/13

Assemble last 2

rows of

TDAs & WSF

(124-130, 224-230,

324-330, 424-430)

onto TSA

Initial

TDA/TSA

I&T in B7

Install & test

1st & 2nd flight

Chassis onto

ACD

Install & test

remaining six

flight

Chassis onto

ACD

1/27/05 – 2/10/05

2/23/05 – 3/4/05

2/11/05 – 2/23/05

2/10/05

1/25/05 – 1/27/05

1/14/05 – 1/25/05

1/14/05

ACD Subsystem

Efficiency

Verification test

(include rotate

ACD 90 degree)

Vibration Test

EMI/EMC Test

Pre-

Environmental

Review (PER)

Install Thermal

Blanket &

MMS

ACD Full

Functional

Test

ACD

Integration

complete

4/12/05-4/19/05

(was 3/26/05 – 4/2/05)

3/4/05 –3/10/05

3/10/05 – 4/7/05

4/7/05 – 4/8/05

4/11/05

4/19/05 – 5/17/05

Mass Properties

Pre-ship

Review (PSR)

Acoustic Test

Thermal Balance/

Thermal-Vac

Test

Post-ship

Checkout &

Full Functional

Test at SLAC

ACD ship

to SLAC


Near term milestones

Near Term Milestones


Interdependencies

Interdependencies

  • EGSE/G3 – Ongoing development with I&T and Electronics groups.

    • LAT team to arrive at Goddard tomorrow.

  • 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 program

Issues, 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 variances

ACD 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 variances

ACD 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 variances1

ACD 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 cost

Threats to Schedule and Cost

  • GASU/G3 EGSE

  • PMT Assembly

  • Electronics assembly and test

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


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