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THEMIS MISSION PRE-SHIP REVIEW Mission Assurance Manager Ron Jackson

THEMIS MISSION PRE-SHIP REVIEW Mission Assurance Manager Ron Jackson University of California - Berkeley. QA Audit of I & T Activities. Remaining Risk Items. * ESA AMPTEK – A121 Failure Analysis/PFR - 159

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THEMIS MISSION PRE-SHIP REVIEW Mission Assurance Manager Ron Jackson

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  1. THEMIS MISSION • PRE-SHIP REVIEW • Mission Assurance Manager • Ron Jackson • University of California - Berkeley

  2. QA Audit of I & T Activities

  3. Remaining Risk Items • * ESA AMPTEK – A121 Failure Analysis/PFR - 159 • - Silver Dendrites are shorting non-common inputs to a dual-inputs NAND die that directly provides the device output. Shorting these two inputs likely causes the device to not operate as expected. • - It appears that a manufacturing or workmanship defect resulted in displaced silver and also the presence of moisture, at least in the localized area, and precipitated this failure. • - Additional failure analysis was performed to determine if more dendrites found: • 1. 2 each DPA with no failures. • 2. 3 each RGA with very low level of moisture. • 3. 10 each, 1000hrs life test, with units opened and checked for • dendrites. • Schedule to complete by November 10, 2006. Risk = Low

  4. Remaining Risk Items • * Solar Array Diode Board/PFR - 165 • - Risk statement: • If application of conformal coating to the solar array diodes impacts the solar array functioning after extreme temperatures, then one or more of the probes may lose power after shadow periods • - Impact: • Loss of power leading to loss of some science • - Probability: • NASA certified technicians applied the coating in NASA standard techniques and 100% verified using NASA inspectors. Panels were taken to flight temperatures plus margin in system thermal vacuum and then successfully lamp-tested afterward (the test that C/NOFS failed). • Our assessment is that P = 1,I = 1, P*I =1 (low) • - Note: • First long shadows occur following minimum science data collection.

  5. Remaining Risk Items • * Probe #1 Broken Piece of Mirror/PFR – 221 • - With the –Y solar array removed from Probe 1, a piece of inspection mirror was found lying on the bottom deck during closeout inspection, below the fuel tank in the –X-Y corner. • - The source of the piece of mirror is not known. Previous inspections of the spacecraft bus did not show signs of broken glass, shards of glass, or any other foreign material. A interview of Swales THEMIS inspection and test personnel was conducted – No broken or missing mirrors. Also a survey of Berkeley inspection mirrors returned no broken or missing mirrors. It is determined that the piece of mirror was dislodged during environmental testing and the associated probe handling (roll-overs). • - The spacecraft was thoroughly inspected and no other foreign material found. Future inspections, with QA presence, will continue to be performed on the spacecraft if the bus is opened. • - Open until final probe closeout at ASO in December 2006. Risk = Low

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