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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 David.J.Thompson@nasa.gov

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

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  1. 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 David.J.Thompson@nasa.gov Thomas.E.Johnson@nasa.gov

  2. 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)

  3. Recent Accomplishments - Electronic Component Status

  4. 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)

  5. 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

  6. 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.

  7. 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

  8. Near Term Milestones

  9. 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.

  10. 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)

  11. 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.

  12. 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

  13. 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

  14. 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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