GLAST LAT ProjectMonthly Review, November 3, 2004 Tracker SubsystemP. S. Drell 1 GLAST Large Area Telescope: Tracker Subsystem WBS Persis S. Drell Stanford Linear Accelerator Center LAT Deputy Project Manager Gamma-ray Large Area Space Telescope

GLAST LAT ProjectMonthly Review, November 3, 2004 Tracker SubsystemP. S. Drell 2 Outline Technical Status- last month’s accomplishments –Issues identified and closure plans –Status of flight hardware Cost and Schedule Status –Tower A Schedule –Delivery schedule for Tower B—Tower 16

GLAST LAT ProjectMonthly Review, November 3, 2004 Tracker SubsystemP. S. Drell 3 Accomplishments and Issues Identified in Tower A Fabrication Tracker Tray Fabrication –Bias circuit bonding problem resolved MRB 10/1/04 –Flight tray production restarted 10/4/04 Tray Production Status (Plyform + INFN) –>90 bare trays (no converter or bias circuits) produced –Converter production Tiles for Tower A at Plyform etched in Turin, primed in Plyform Tiles for Tower B and beyond being etched and primed at GSFC –Delivery rate plan of 300 tiles/week –21 trays completed with converter and bias circuit through T/V 1 failure –2 tiles had primer delaminate from converter foils (Turin process) –Cause under investigation 3 others show bubbles (before T/V) –Disposition under discussion

GLAST LAT ProjectMonthly Review, November 3, 2004 Tracker SubsystemP. S. Drell 4 Tray Production Status (example) FLIGHT TRAYS SUMMARY 10T-VAC done 20Panel with payload 56ESPI done 73Bare Panel Qty-FHProduction Step

GLAST LAT ProjectMonthly Review, November 3, 2004 Tracker SubsystemP. S. Drell 5 Issues Identified in Tower A Fabrication Tower A Tray Assembly Status (G&A) –Anomaly found in assembly: missing connections on MCM WORK IS STOPPED –1 tray with MCMs bonded (but no SSDs yet) found to have a problem with no bias from the MCM to the two center ladder attachment points on the bias circuit. –One caused by resistor badly soldered on MCM –Cause of other is not yet known –6 more MCMs of 32 tested in Pisa have at least 1 missing bias or HV connection 18+ tested at SLAC do not show any problem –Currently applying all available resources in Pisa and at SLAC to determine root cause –G&A work is ~ 1 week behind nominal Tower A fabrication schedule at this point

GLAST LAT ProjectMonthly Review, November 3, 2004 Tracker SubsystemP. S. Drell 6 MCM and Bias Circuit

GLAST LAT ProjectMonthly Review, November 3, 2004 Tracker SubsystemP. S. Drell 7 Issues Identified in Tower A Fabrication Other Issues for Tower A –In Tower 0, identified interference between connector on MCM and sidewall on many trays New MCM bonding procedures finalized to ensure connector stay clear –Critical hardware for Tower A assembly in work Impacted by SLAC shutdown Pulled work from shops and sent outside to complete Flight cables for Tower A a critical problem

GLAST LAT ProjectMonthly Review, November 3, 2004 Tracker SubsystemP. S. Drell 8 Issues Identified in Flight Cable Production Two technical issues identified: –Separations between barrel plating and internal layers. –Bubbles in adhesive holding connector to cable

GLAST LAT ProjectMonthly Review, November 3, 2004 Tracker SubsystemP. S. Drell 9 Path forward with Tracker Flex Cables Parlex –CAP developed for plating process Early tests validated new process Coupon tests on cables with new plating process so far test acceptable –Process problems in cable assembly under discussion Bubbles in the adhesive between the flex and the Omnetics connectors. –Stop work issued—QA visit tomorrow supported by tracker personnel –Delivery schedule continues to be unreliable –Project Manager to visit next week –Option: If new process has good coupons, consider getting bare cables and assemble at company of our choosing Investigations underway Current proposal to install cables in hand (with original plating process or with adhesive bubbles) if necessary to stay on schedule for Tower A assembly –Tower A will have lien to be resolved at a later time

GLAST LAT ProjectMonthly Review, November 3, 2004 Tracker SubsystemP. S. Drell 10 Alternate sources for tracker flex cables Developing alternate source for full length cables PO at Titan with 12/1 delivery to produce 5 C4 cables Will proceed with QA source inspection if looks viable Developing option of 2 short cables with ‘rigid-flex’ joint Need to validate design New drawings in process –Anticipate flight order with alternate source by 12/15

GLAST LAT ProjectMonthly Review, November 3, 2004 Tracker SubsystemP. S. Drell 11 Alternate sources for tracker flex cables

GLAST LAT ProjectMonthly Review, November 3, 2004 Tracker SubsystemP. S. Drell 12 Issues Identified in MCM Production 343 units delivered to SLAC –325 through burn in and final test at SLAC –Need 686 for 18 towers + electronics group –Production at Teledyne currently stopped MCM Issues –Pitch adaptor 13.5% drop out at MIP 1 due to broken traces (visual inspection) Brittle Ni plating cracks easily in bend region, sometimes also cracking Cu Two new pitch adaptor concepts in work to eliminate problem –Option 1: masking over bend radius –Option 2: selective plating process for Ni plating »New designs to be qualified when production at Teledyne resumes (scheduled for 11/15) New electrical test fixture in test for detecting broken traces

GLAST LAT ProjectMonthly Review, November 3, 2004 Tracker SubsystemP. S. Drell 13 Issues Identified in MCM Production MCM Issues (cont.) –MCM Leakage Current Problem 8 boards have developed low resistance between layers 7 and 8 (120 V potential difference) of the multilayer board during burn-in. Destructive Physical Analysis in process at Goddard and CALCE to determine root cause –Moisture during lamination or reflow, contamination, and conductive filament growth are all possibilities. In case it is moisture, a pre-reflow bake has been added. Prepreg will be vacuum dried if more PWBs are made. The problems seem clustered, so we are holding PWBs from the same panels as failed boards The MCMs failed 2, 3.5, 4, 6, 10, 20, and 75 hours into our 168 hour burn-in where about 350 others did not fail giving hope that the burn- in catches almost all the problems. –Data readback errors Some MCMs are too sensitive to clock duty factor during burn-in –Related to quality of clock received by GTRC –Problem mitigated by changing termination resistor on cables

GLAST LAT ProjectMonthly Review, November 3, 2004 Tracker SubsystemP. S. Drell 14 Issues Identified in MCM Production MCM Conformal Coating Problems –Issues identified in QA with peeling, contamination and bubbles –A full inspection of all units has been completed. CC got into many connectors. –They will be carefully cleaned CC is lifting in small areas near components. –200 thermal cycles did not make the lifting worse. –3 vacuum cycles on 4 MCMs did not make lifting worse –The risk involved in reworking them may be greater than in using them as is. CC is thin or missing on sides of many components –Due to spraying from only one direction –Mostly on non-conductive sides of “tall” components –Not clear if rework is practical. (CC could end up too thick.) –MRB 10AM 11/3/04 In parallel, manufacturing process is being improved to prevent these problems on future units.

GLAST LAT ProjectMonthly Review, November 3, 2004 Tracker SubsystemP. S. Drell 15 Issues Identified in MCM Production Restart of MCM Flight Production –Need improved ESD and PWB bake-out Waiting for final quote –Implement conformal coat process improvments –Pitch adapter re-qualification program –MC restart MRR at Teledyne anticipated 11/15/04

GLAST LAT ProjectMonthly Review, November 3, 2004 Tracker SubsystemP. S. Drell 16 Flight Hardware Drawings Status Top/Bottom Tray Panels (including flexures) –All drawings complete and released. Interface Hardware –All complete and released. Mid Tray Panels –Some rework and improvements of the drawings to reflect as-built condition are in work. Tray Assembly (Bonding MCMs + Ladders to tray panels) –All complete and released. Sidewall Drawings –All complete and released. Heat Straps –Complete and released.

GLAST LAT ProjectMonthly Review, November 3, 2004 Tracker SubsystemP. S. Drell 17 Flight Hardware Drawings Status Flex-Circuit Cables –All complete and released. Drawing revision to match as built in progress Top Mount Cable Retainer and Alignment Hardware –All complete and released. Tower Assembly Drawing –Complete and in release cycle Electronics, including SSDs, MCMs, Bias Circuits, ASICs, etc.: all complete and released. –Ladder drawing revised to match as built. Ready for release

GLAST LAT ProjectMonthly Review, November 3, 2004 Tracker SubsystemP. S. Drell 18 Status of Parts & Materials from SLAC ItemStatusIssues MCMs~40 will be hand carried to Italy Sunday for Tower B Resolution of conformal coat issues have delayed shipment Flex-Circuit CablesNo complete flight sets in handProduction problem at Parlex In discussion with alternate vendors Ti Corner Brackets & Flexures Flight order complete Bottom-tray closeouts Flight order complete Interface cones & studs The Tower-A set is ready and the remainder is in fab Threads on some studs are out of spec. Return to AMT for rework. Nytemp patch will be run-in. Hex nutIn hand

GLAST LAT ProjectMonthly Review, November 3, 2004 Tracker SubsystemP. S. Drell 19 Status of Parts & Materials from SLAC ItemStatusIssues ShimsEnough in hand for Tower A, but working on Ni plating Top Tray Corner Brackets Two tower sets on-hand. CMM inspection this week Sidewall PrepregItaly purchased enough already for at least 2 or 3 towers. Rest is in shipment Ti Sidewall washers Sufficient quantities are in Italy Sidewall FastenersAll are except for bottom tray are in hand and verified Cytec BR-127 Primer A large quantity was shipped last week and arrived okay Bias CircuitsPlenty in Italy for tray mass production to begin CR released. Coupon via plating thickness issue resolved

GLAST LAT ProjectMonthly Review, November 3, 2004 Tracker SubsystemP. S. Drell 20 Status of Parts & Materials from SLAC ItemStatusIssues Heat strapsTower A set plus spares are in Italy. Balance at SLAC. CMM and ship to INFN. Locktite 401 for heat straps Being shipped to Italy Solithane (for locking screws) Being shipped to Italy, will ship to INFN next week Nusil silicone adhesives Sufficient quantities now in Italy Aeroglaze paint and primer Sufficient quantities now in Italy HoneycombFull flight order is in Italy Carbon Carbon for Tray Closeouts Full flight order is in Italy Flex Cable Foam Compression Pads Placing order. Ship to INFN next week. INFN to perform 1 st article fit check. M2.5 x 100 degReplacement units being orderedOriginal order has wrong head

GLAST LAT ProjectMonthly Review, November 3, 2004 Tracker SubsystemP. S. Drell 21 Status of GSE from SLAC ItemStatusIssues Vibration Fixture (Grid Simulator) Ten units received and CMM inspected. Adding insert for electrical grounding Inner Shipping Container Tower-A container is on-hand and is being proof tested Cable Holding PlateIn hand and being proof tested this week. Will ship with all associated H/W. Static Test Grid Simulator In Italy, already used for Tower A Lifting FixtureOne is in hand and proof tested. 2 more will also be made for use in Italy. Outer Shipping Container 1 st article is at SLACNeeds drop test qualification performed. Outsource test due to SLAC stand-down.

GLAST LAT ProjectMonthly Review, November 3, 2004 Tracker SubsystemP. S. Drell 22 Status of GSE from SLAC ItemStatusIssues Cable Bending ToolProduction models in fab Tools for Cone Alignment and Extraction Enough tools are in hand for Tower A assembly in Italy. Improved stud socket in fab. EGSE Sets4 sets are in Italy. One more for T/V testing is under test at SLAC prior to shipping. Long EGSE Cables for T/V Test 1 set delivered to Italy. 2 more are in work C0 Cables for Stacked Tray Tests Enough in hand for Tower ARemaining test sets in Italy will be equipped with reject cables Breakout Boxes for Tray Testing 2 are in Italy~10 more in fab at SLAC

GLAST LAT ProjectMonthly Review, November 3, 2004 Tracker SubsystemP. S. Drell 23 Status of GSE from SLAC ItemStatusIssues Transport Environmental monitors Pisa has nine units ESD wrap for inner container Order placed. Ship to INFN next week. Desiccant pads (for inner container On hand at SLAC. Ship to INFN this week

GLAST LAT ProjectMonthly Review, November 3, 2004 Tracker SubsystemP. S. Drell 24 PMCS Schedule & Cost Variance September: Schedule variance decreased from -$736k to - $575k on total $15,274 BCWI –Schedule has actually degraded due to work stoppage at Teledyne –Improvement in PMCS comes from receiving prepreg used for sidewalls –Keep in mind most of Tracker assembly work is in Italy and not tracked by this schedule variance calculation Cumulative Cost Variance: -$456k –Large payment made to Teledyne for MCM’s received before work stoppage

GLAST LAT ProjectMonthly Review, November 3, 2004 Tracker SubsystemP. S. Drell 25 Schedule Status: Tower A Campaign The Tracker team is focused on delivery of Tower A to I&T –Updated plan: Tower A ships 12/16/04

GLAST LAT ProjectMonthly Review, November 3, 2004 Tracker SubsystemP. S. Drell 26 Schedule Status: Tower Delivery Schedule Updated plan: –Start production 10/4 –Plyform produces 4 trays/day starting 11/1 –G&A going to 2 shifts Extra CMM Extra Wire bonder Tower 13,14 arrive in May