1. GLAST LAT ProjectDOE/NASA Mechanical Systems Peer Review, March 27, 2003 Document: LAT-PR-0XXXX Section 6.0 Subsystem Verif. Test Plan 1 GLAST Large Area Telescope: Mechanical Systems Peer Review March 27, 2003 Section 6.0 – Subsystem Verification Test Plans Leonard Lee SLAC Systems Engineer lhlee@slac.stanford.edu Gamma-ray Large Area Space Telescope

2. GLAST LAT ProjectDOE/NASA Mechanical Systems Peer Review, March 27, 2003 Document: LAT-PR-0XXXX Section 6.0 Subsystem Verif. Test Plan 2 Topics Agenda Overview Verification Test Levels Mechanical Subsystem Verification Matrix Verification Items Verification Test Flow

3. GLAST LAT ProjectDOE/NASA Mechanical Systems Peer Review, March 27, 2003 Document: LAT-PR-0XXXX Section 6.0 Subsystem Verif. Test Plan 3 Overview The intent of the Mechanical Subsystem verification plan is to ensure that the component, assembly and subsystem hardware: - Verify workmanship and performance of hardware per Level III and IV subsystem specification - Provides traceability back to requirements in the Level III and IV subsystem specifications - Satisfies LAT Performance Specification (LAT-SS-00010) - Compatible with other LAT subsystem’s interfaces

4. GLAST LAT ProjectDOE/NASA Mechanical Systems Peer Review, March 27, 2003 Document: LAT-PR-0XXXX Section 6.0 Subsystem Verif. Test Plan 4 Verification Test Levels Mechanical Systems hardware verified with tests performed at one or more of the following test levels: –Qualification –Proto-Flight –Flight Hardware test levels driven by –Design Maturity of Hardware –Hardware Flight History

5. GLAST LAT ProjectDOE/NASA Mechanical Systems Peer Review, March 27, 2003 Document: LAT-PR-0XXXX Section 6.0 Subsystem Verif. Test Plan 5 Test Levels/Durations Table Shaded areas do not apply. 1- If qualified by analysis only, positive margins must be shown for load factors of 2.0 on yield and 2.6 on ultimate. Composite materials cannot be qualified by analysis alone. Note: Test and Analysis levels for composite strictures, including metal matrix, requires acceptance level testing to 1.25 x Limit Level. 2- As a minimum, the test level shall be equal to or greater than the workmanship level. 3- The sweep direction should be evaluated and chosen to minimize the risk of damage to the hardware. If the sine sweep is used to satisfy the loads or other requirements, rather than to simulate an oscillatory mission environment, a faster sweep rate may be considered, e.g., 6-8 oct/min to reduce the potential for over stress. 4- Normal operating temperature for the LAT is –10° C to 25° C. Survival temperature is –20° C to 40° C. 5-The number of thermal cycles for spares is 8.

6. GLAST LAT ProjectDOE/NASA Mechanical Systems Peer Review, March 27, 2003 Document: LAT-PR-0XXXX Section 6.0 Subsystem Verif. Test Plan 6 Mechanical Subsystem Verification Matrix LEGEND Assembly Level Unit TypeVerification Method S – SubsystemPF – Proto FlightQ – QualT – Test TQ – Test, Qualification Level A- AssemblyF – FlightE – Engineering ModelA –AnalysisTA – Test, Acceptance Level C – ComponentS – SpareV – Verification ModelM – MeasurementP – Proof I – Inspection

7. GLAST LAT ProjectDOE/NASA Mechanical Systems Peer Review, March 27, 2003 Document: LAT-PR-0XXXX Section 6.0 Subsystem Verif. Test Plan 7 Verification Items Mechanical Systems hardware to be verified consists of the following assemblies and components: –Heat Pipes* –4x4 Grid Structure –X-LAT Thermal Plate/Mid-Plate* –Grid Box Assembly –Radiator Assemblies* –Thermal Control System(TCS)* * Addressed in Section 4 of this review

8. GLAST LAT ProjectDOE/NASA Mechanical Systems Peer Review, March 27, 2003 Document: LAT-PR-0XXXX Section 6.0 Subsystem Verif. Test Plan 8 4 x 4 Grid Structure Verification Mass properties and c.g. verified Dimension Check verified Proof Test of inserts

9. GLAST LAT ProjectDOE/NASA Mechanical Systems Peer Review, March 27, 2003 Document: LAT-PR-0XXXX Section 6.0 Subsystem Verif. Test Plan 9 Grid Box Assembly Verification Grid Box Assembly Dimension Check Grid Box Assembly Functional Test Grid Box Assembly Thermal Cycle Grid Box Assembly Static Load Test Grid Box Assembly Alignment Check Grid Box Assembly Mass Properties/C.G. Grid Box Assembly Functional Test Grid Box Assembly Functional Test

10. GLAST LAT ProjectDOE/NASA Mechanical Systems Peer Review, March 27, 2003 Document: LAT-PR-0XXXX Section 6.0 Subsystem Verif. Test Plan 10 Mechanical Verification Tests Dimensional Check Mass Properties and C.G. verified Alignment verification per LAT Survey & Alignment Plan (LAT- MD-01586)

11. GLAST LAT ProjectDOE/NASA Mechanical Systems Peer Review, March 27, 2003 Document: LAT-PR-0XXXX Section 6.0 Subsystem Verif. Test Plan 11 Functional Test Grid Box Assembly to undergo functional verification –Resistance check of heaters –Isolation check of harnesses –Continuity check of harnesses

12. GLAST LAT ProjectDOE/NASA Mechanical Systems Peer Review, March 27, 2003 Document: LAT-PR-0XXXX Section 6.0 Subsystem Verif. Test Plan 12 Static Load Test Test Objectives –Primary Objective: Verify static strength and stability of the Grid Box Assembly under worst case Delta II-H vehicle loads of 1.25 times limit loads Achieve maximum stresses in grid box assembly Load subsystem interfaces to qualification design loads –Secondary Objective: Verify the design analysis process by comparing measured strains and deflections to predictions from the finite element analysis model Test Success Criteria –Successful test completion is when all load cases have been performed and it is verified that no yielding, buckling, de-bonding, or fractures have been observed. A visual inspection is to be performed after each load case to check the critical joints and bonded interfaces A review of all pertinent data during test including deflections and strains to verify linearity

13. GLAST LAT ProjectDOE/NASA Mechanical Systems Peer Review, March 27, 2003 Document: LAT-PR-0XXXX Section 6.0 Subsystem Verif. Test Plan 13 Grid Box SLT Configuration The SLT configuration consists of all primary structure grid box components as described below The SLT article will be grounded at the SC Mount Brackets with correct degrees of freedom Radiator Mount Brackets - 4X - Flight EMI Skirts - Flight XLAT Plate - Flight Grid - Flight Down spout HPs - 12X - Flight Calorimeter Plates -16X - Flight-like Spacecraft Mount Brackets - 4X - Flight

14. GLAST LAT ProjectDOE/NASA Mechanical Systems Peer Review, March 27, 2003 Document: LAT-PR-0XXXX Section 6.0 Subsystem Verif. Test Plan 14 SLT Instrumentation (preliminary) Strain Gauge Requirements –Sensitivity range is between 0 and 3000 microstrains –Strain gauge type LE (lead wires already attached) –Approximately 100 locations will be specified in the test procedure Displacement Gauge Requirements –Approximately 25 locations will be specified in the test procedure

15. GLAST LAT ProjectDOE/NASA Mechanical Systems Peer Review, March 27, 2003 Document: LAT-PR-0XXXX Section 6.0 Subsystem Verif. Test Plan 15 SLT Load Cases Specific load cases and load application methods are in work Load cases will test –Max X + max Z loads applied to Grid –Max Y + max Z loads applied to Grid –Radiator Mount Bracket loads –ACD insert loads –TRK flexure insert loads

16. GLAST LAT ProjectDOE/NASA Mechanical Systems Peer Review, March 27, 2003 Document: LAT-PR-0XXXX Section 6.0 Subsystem Verif. Test Plan 16 Thermal Cycle Test Thermal Cycle Grid Box Assembly to “Qualification” level 4 cycles to protoqual temperatures Thermal vacuum test meets MAR but thermal cycle may be adequate(TBR) –Verify Flight heater, thermistors and thermostats can be performed in ambient pressure –Verify Downspout & Top Flange Heat Pipe bond integrity (mechanical & thermal). Heat transport of heat pipes are verified at ambient pressure at component level X-LAT plates thermal vacuum cycled at component level Thermal performance of X-LAT and Heat Pipes are verified in Thermal Balance test

17. GLAST LAT ProjectDOE/NASA Mechanical Systems Peer Review, March 27, 2003 Document: LAT-PR-0XXXX Section 6.0 Subsystem Verif. Test Plan 17 Thermal Cycle Test Configuration Thermal chamber sized to accommodate Grid Box assembly Grid Box Assembly with test heaters (STE) and thermocouples (STE)

18. GLAST LAT ProjectDOE/NASA Mechanical Systems Peer Review, March 27, 2003 Document: LAT-PR-0XXXX Section 6.0 Subsystem Verif. Test Plan 18 Mechanical Systems Verification Test Flow Grid Structure -Proof Load -Mass Properties & C.G. -Dimension Check Radiator Mount Bracket Grid Box Base Assembly -Static Load -Thermal Cycle -Mass Properties & C.G. -Dimension Check -Alignment -Functional Disassemble Grid Box Base Assembly X-LAT Plates Mid-Plate -Static Load Test -Mass Properties & C.G. -Dimension Check -Thermal Vacuum Test -Static Load Test -Mass Properties & C.G. -Dimension Check Radiator -Sine Sweep -Acoustic -Mass Properties & C.G. -Dimension Check -Interface Verification -EMI/EMC -Functional Assemble Radiator pair test configuration -Thermal Balance -Mass Properties & C.G. -Dimension Check LAT Integration LAT Level Verification Tests Grid Box Base Assembly X-LAT Plates Radiators Grid Assembly