Transcript ppt

GLAST LAT Project
Gamma-ray Large
Area Space
Telescope
F-to-F, June 15, 2005
GLAST Large Area Telescope:
Tracker, W.B.S 4.1.4
Face-To-Face June Meeting
Robert Johnson
U.C. Santa Cruz
[email protected]
4.1.4 Tracker
R.P. Johnson
1
GLAST LAT Project
F-to-F, June 15, 2005
Tower Status
• Towers A, B, 1, 2, 3, 4, 5:
– Handed off to I&T
• Tower 6:
– Assembled and electrically tested with C5, C6, and C7 cables missing.
– Sidewalls installed and full alignment CMM measurements done.
– Stored in its inner shipping container in the Pisa cleanroom.
• Tower 7:
– Assembly is in progress in Pisa.
– Only 2 cables (C0 and C1) are available in Pisa for this assembly.
• Tower 8:
– All but 3 (heavy) mechanical panels were delivered by Plyform as of
Monday of this week. The remainder should be delivered this week.
– G&A is assembling Tower-8 trays.
• Tower 9:
– At least most of the Tower-9 mechanical panels should be delivered by
the end of this week.
4.1.4 Tracker
R.P. Johnson
2
GLAST LAT Project
F-to-F, June 15, 2005
Tray Panel Fabrication
• Plyform received a payment on their first invoice under the ASI/G&A
subcontract, which helped defuse many concerns.
• Plyform has been doing an excellent job at delivering trays.
• There have been some potential material problems:
– Defective bias circuits (see the following slide). Replacements are on
order.
– Carbon-carbon materials: the last orders were received and shipped to
Italy.
– Tungsten tiles could hold up the show.
• The new orders were received in Italy and shipped to GSFC.
• Substantial customs delays resulted.
• Pisa has said that delays could result if the tiles are not receive in Italy by
about June 20 (next week).
• The work is now in progress at GSFC, but I don’t yet have a status update
on when the first batches will be ready.
4.1.4 Tracker
R.P. Johnson
3
GLAST LAT Project
F-to-F, June 15, 2005
Bias Circuit Issue
•
The root cause of the bad circuits was never determined.
– The bad circuits have a different color in the region where there is no copper
plane. See below.
•
However, a visual screening procedure was discovered, and we found that a
total of 75 circuits have to be replaced.
This region
delaminates
easily in the
bad circuits.
FAILED
4.1.4 Tracker
PASSED
R.P. Johnson
4
GLAST LAT Project
F-to-F, June 15, 2005
MCM Production
Shipment to SLAC
Plan
Actual
600
Cumulative Number
500
400
300
200
100
7/4/05
6/27/05
6/20/05
6/13/05
6/6/05
5/30/05
5/23/05
5/16/05
5/9/05
5/2/05
4/25/05
4/18/05
4/11/05
4/4/05
3/28/05
3/21/05
3/14/05
3/7/05
2/28/05
2/21/05
0
Week Starting
• Production halted for one week to rework the tooling for flex trimming.
• Production is underway again this week. 15 MIP-2 tests Mon./Tues.
• Only about 2 more weeks of production are needed for flight towers.
4.1.4 Tracker
R.P. Johnson
5
GLAST LAT Project
F-to-F, June 15, 2005
MCM Production Issues
• We believe that we have resolved the financial issues remaining in
the contract with a good compromise between SLAC and Teledyne
(many thanks to Ladan Saghafi in SLAC purchasing!).
• Omnetics connector deliveries are critical for keeping the Teledyne
production rolling.
– The next delivery date given by Omnetics, July 1 for 400 units, is most
likely too late to avoid a work stoppage at Teledyne.
– Jeff Tice is pushing Omnetics to deliver some connectors earlier than
that, but they have been strongly resisting so far.
– We have started removing connectors from failed flight MCMs in order
to build up a stock of usable connectors, just in case. They are now in
the hands of QA for cleaning and inspection.
• The first production trial of conformal coating (4 MCMs) had
problems that have not yet been resolved. Production is continuing
with the in-house Teledyne process. Moving to the new process
becomes less and less attractive as we near the finish line.
4.1.4 Tracker
R.P. Johnson
6
GLAST LAT Project
F-to-F, June 15, 2005
Flex-Circuit Cables
• The last Tower-6 cable is supposed to ship from Parlex June 24
• I’m hoping to get some firm information on Tower-7 cables from Parlex
today. In principle they are only slightly behind Tower 6.
• Cables are dribbling in from Parlex, with 4 shipped last week and
hopefully at least 3 this week.
• Parlex was funded to make 2 improvements:
– Work weekends
– Retool the longest cables to go 4 per panel (not diagonal) on a new panel
size that Parlex is now processing (this will not pay off immediately)
• We are investigating relaxing the annular ring requirements to IPC
Class-3 specs to improve the yield.
• Pioneer flex-circuit manufacturing is in progress, with all circuits due to
be fabricated by July 1.
• Pioneer is also actively working on assembly issues, including making
test assemblies.
4.1.4 Tracker
R.P. Johnson
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GLAST LAT Project
F-to-F, June 15, 2005
Tracker Tower RFI Schedule
Tower 6
July 11
Tower 7
July 13
Tower 8
July 29
Tower 9
August 2
Tower 10
August 16
Tower 11
August 18
Tower 12
August 25
Tower 13
September 7
Tower 14
September 9
4.1.4 Tracker
These are my guesses, based on my MS
Project schedule.
Towers 6 and 7 are already in trouble due to
lack of cables.
INFN believes that up through Tower 14 can
still be assembled and tested in Italy by end
of August if cable sets start arriving regularly
no later than mid July (assuming that at least
Towers 6 and 7 are equipped and tested
earlier).
There are potential problems with competing
for access to the Alenia vibration facilities.
R.P. Johnson
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