GLAST LAT Project LAT Mgr s Meeting November 17

GLAST LAT Project LAT Mgr’s Meeting November 17, 2004 LAT Planning Meeting Mechanical/Thermal Systems November 2004 Marc Campell 1

GLAST LAT Project LAT Mgr’s Meeting November 17, 2004 THE GRID IS HERE! 2

GLAST LAT Project LAT Mgr’s Meeting November 17, 2004 MECH Milestones R B s. T ate D 3

GLAST LAT Project LAT Mgr’s Meeting November 17, 2004 LM ETC • Formal ETC from LM is in progress. This data has not been submitted by LM. 4

GLAST LAT Project LAT Mgr’s Meeting November 17, 2004 LM Risks • Radiator – Timely headcount roll-off – First time use of bonding/assembly tool & procedures (No full sized Dev hardware). MFG marching army costs – Radiator Assembly design doesn’t accommodate repairs – Handling risks – large, fragile hardware – Cost over runs in testing • Fixture design (Acoustic) • Facility scheduling – competing with other LM priority programs • Resolution of TCS anomalies during Thermal Balance testing. Test marching army costs – Satisfactory replacement of key personnel 5

GLAST LAT Project LAT Mgr’s Meeting November 17, 2004 LM De-scope Options • Radiator Vibe testing – Current plan • 5 -150 Hz low level sine sweep in 3 axes • 5 -50 Hz sine sweep in 2 axes • 5 -150 Hz low level sine sweep in 3 axes • Acoustic test • 5 -150 Hz low level sine sweep in 3 axes (plan to substitute - 6 d. B acoustic run for this) 6

GLAST LAT Project LAT Mgr’s Meeting November 17, 2004 LM De-scope Options (cont) • Radiator Vibe testing - De-scope options – Defer 5 -150 Hz sine sweep until LAT level • Perform twang and/or tap test of Radiator for model validation (first modes only) – Delete 5 -150 Hz sine sweep for post test signatures • Perform -6 d. B Acoustic runs before & after P/Qual level Acoustic test for pass/fail evaluation – Delete 5 -50 Hz sine sweep • Qual by analysis (LM is defining where there are inadequate margins for this) • Interface potted inserts are tested by witness coupons that are bonded simultaneously on the sides of the Radiator panel during layup – These actions carry low to moderate risk per J. Ku – Cost savings ~$160, 000 (8 LM EM x. 75 month)? 7

GLAST LAT Project LAT Mgr’s Meeting November 17, 2004 LM De-scope Options (cont) • X-LAT Thermal Testing – Perform Thermal Cycle test in air instead of thermal vacuum – This is primarily a workmanship test and there is low risk. – Violates MAR requirement for 4 Thermal Vacuum cycles. – Tom Mc. Carthy indicated that 8 thermal cycles in air would be acceptable to him. – Need to implement now to maximize savings (test preparations are underway). – LM will investigate the feasibility of this change. – Cost Savings ~$50, 000 (~1/2 of quoted cost) 8

GLAST LAT Project LAT Mgr’s Meeting November 17, 2004 Grid #2 Static Load Test To Go • SLT budget – Grid Box #2 Assy Operations – Design & Fab MGSE/fixtures – Test – Total $34, 170 $78, 650 $180, 000 $292, 820 – Note: This test does not drive LAT schedule • Risks – Test house not selected – If FE model doesn’t correlate then additional test cases will be required – There is sufficient budget for these contingencies • De-scope options – None. This test allows deletion of LAT Sine Vibe (LAT descope). – The number of load cases required has been reduced. 9

GLAST LAT Project LAT Mgr’s Meeting November 17, 2004 BACK-UP 10

GLAST LAT Project LAT Mgr’s Meeting November 17, 2004 MECH ETC 11

GLAST LAT Project LAT Mgr’s Meeting November 17, 2004 MECH BOE Mechanical Systems Labor Increases $140. 5 K • This increase consists of $40 K for the Multi- Layer Insulation (MLI) blanket design. Very early on in the program, the ACD subsystem was responsible for the LAT MLI design and fabrication. Because of the complexity of the MLI interfaces with the Spacecraft, Radiators and LAT external features, it was decided to pull this work back to SLAC. Additionally, Thermal Engineering support is now available at SLAC to support this task. • $100. 5 K has been added for Mechanical Systems support of the LAT I & T efforts at the end of FY 05. These tasks include X-LAT Plate installation and Radiator fit check and shimming operations on the LAT prior to LAT shipment. 12

GLAST LAT Project LAT Mgr’s Meeting November 17, 2004 MECH BOE (con’t) Mechanical Systems Material Increases $1, 620. 5 K This increase consists of $1, 580. 5 K (TBR) additional funding to complete the Lockheed Martin contract. There are two main cost drivers: 1) Lockheed schedule delays and 2) SLAC imposed changes. • 1) LM overran the following tasks: – Radiator design, – Radiator analysis (structural development), – Radiator tooling design & fab, – Radiator Thermal Controls design and – X-LAT Plate analysis. • These overruns have left insufficient budget for the remaining tasks to be completed. 13

GLAST LAT Project LAT Mgr’s Meeting November 17, 2004 MECH BOE (con’t) • 2) The following changes were made after Lockheed submitted their February 2004 cost proposal and resulted in extra costs (WAG $150 K). – Additional thermal analyses for the X-LAT plate to electronics box interface, for thermal combs (heat shunt for the GASU box) and for the U-shaped heat pipes that were added then removed from the X-LAT plate, – MLI blanket design consultant, – Radiator EMI coupon testing, – Added keying features to the Radiator There is also an additional $40 K for the Multi- Layer Insulation (MLI) blanket fabrication. Very early on in the program, the ACD subsystem was responsible for the LAT MLI fabrication. Because of the complexity of the MLI interfaces with the Spacecraft, Radiators and LAT external features, it was decided to pull this work back to SLAC. 14