Meeting ID: 4886
1. static test status
2. K13d panels
3. tray assembly for the EM tower
4. EM tower vibration planning
5. EM flex cables
6. Thermal vacuum test planning
7. mini-tower status and pitch-adapter issues; last 2 MCMs
Actions to complete in preparation for the vibration test: (Dates are my estimates of latest possible, for July 28 vibe test; let me know if I forgot something)
- Hytec static test of the 1st bottom tray, with YS90 panels, to 125% of CLA loads (July 18)
- Hytec ship 1st bottom tray back to Pisa (hand carry) (July 21)
- Completion of K13d sidewalls, static-test sidewalls, and coupons at Plyform; ship joint coupons to Hytec (July 21)
- Material strength tests of K13d coupons at Plyform (July 23)
- Hytec pull the joint coupons (coupons with inserts) (July 23)
- Hytec static test of the 2nd bottom tray to static-equiv random vibe loads and then to destruction, with K13d sidewalls (July 25)
- Completion of ladder and MCM mounting at G&A; wire bonding, encapsulation of a few layers (July 21)
- Pisa completion of the tower assembly fixture (July 21)
- Bari et al. finalize the vibration test plan and review with GSFC (July 21)
- SLAC ship the vibration fixture and bottom plate and lifting fixture to Pisa (July 14)
- SLAC machine the cable-holding fixture parts for the vibe test and send to Italy with Ronaldo(July 18)
- SLAC finish the flex cable assembly & debugging and send to Italy with Ronaldo (July 18)
- Pisa test and survey the fixtures on the vibration table at Alenia (July 24)
- Pisa assemble the EM tower and install instrumentation (July 25)
- Pisa securing and torque striping of fasteners? (We need a plan here!) (July 25)
- SLAC complete and ship the tower inner shipping container to Pisa, to be used in transporting the tower to Alenia (July 24)
Steve asked if the side flexures are bonded on the bottom tray. The adhesive is only on the screws, whereas the plan had been to bond the entire joint. Some adhesive could still be added in the gap along the face sheet. BJ needs to add this glue joint to the assembly drawing.
K13d panels: The material is being picked up today from customs. Testing of the resin and testing of lamination will be done first, to requalify the material. First thing next week Plyform will do the lamination, maybe tomorrow. Sandro will be there Monday to define the schedule in detail.
Pitch adapter problems. They have wire bonded 4 layers at G&A, 1 double-sided tray and the top/bottom trays. Sandro tried and failed to repair the unbonded flex. 200 channels were lost on the left side (1 to 200). 10 channels are unbonded on one side of double-sided tray as well, due to damage in the trimming process at Teledyne. The finished PWBs were slightly short, such that the Teledyne tool for flex attach tool ended up putting the flex on at a slope, with a lot of glue under the SSD end. This caused bad trimming and bad planarity for wire bonding.
There also appears to be a dimensional problem with the pitch adapters, which are 0.2mm too long, from the first strip to the last. BJ is getting unused pitch adapters measured at SLAC to see if the error is manufactured into them. If not, then it may be a CTE problem at Teledyne, although the problem does not show up in older EM pieces, which used the same layout and the same assembly tooling.
Tom is taking the last two MCMs to Riccardo in Los Alamos. One (106) is electrically perfect, while the other (109) has one dead front-end chip, apparently from damage during encapsulation. Tom is also taking a NASA approved tape for sealing the tracker corners.
G&A is continuing to mount ladders onto trays. 9 trays have ladders. 1 more will be done tomorrow. They will start tomorrow to glue electronics on. They plan to wire bond all, but encapsulate only a few. They will encapsulate more after the shake test and prior to the thermal-vacuum test.
BJ is trying to get a fixture made for holding the cables during the vibration test. BJ will send the fixture drawing to Nanda and Steve for review.
Steve will send Nanda and Robert the static test procedure.
Sandro said that a modal survey of the bottom plates and fixtures need to be done the week before the vibration test. He must have all the fixtures by the 21st. They can be sent with Tom, or with Ronaldo on the 18th.
They will have a meeting at Alenia next week to go over the test plan. The plan will have to be reviewed with GSFC by the 21st.
BJ needs to send the tower lifting device to Pisa also.
Steve reported the that the grid simulator is still missing from the static test setup. They are hoping for it by the end of the week. Hytec will install the strain gauges today and tomorrow. He estimates 2 to 3 days for the test. The tray needs to be in Pisa by the 21st. Nanda suggested the TWI courier service for hand carrying.
Nanda suggested that a face-to-face thermal-vacuum test meeting take place in Pisa following the vibe test.
Sandro reported that the 2nd bottom tray is in transit by DHL, going to Los Alamos.