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Particles and Fields Package Pre-Environmental Review May 22 -23, 2012 03 - Systems Engineering

Mars Atmosphere and Volatile EvolutioN (MAVEN) Mission. Particles and Fields Package Pre-Environmental Review May 22 -23, 2012 03 - Systems Engineering Dave Curtis, PFP Package Manager. Design Changes Since CDR. Changes to thermal design:

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Particles and Fields Package Pre-Environmental Review May 22 -23, 2012 03 - Systems Engineering

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  1. Mars Atmosphere and Volatile EvolutioN (MAVEN) Mission Particles and Fields Package Pre-Environmental Review May 22 -23, 2012 03 - Systems Engineering Dave Curtis, PFP Package Manager

  2. Design Changes Since CDR Changes to thermal design: SWIA and STATIC deck mounted (not isolated) to keep them from over-heating in some cases (early cruise) SWEA, SWIA, STATIC, and SEP thermal radiators changed from black to white paint to keep them cooler in hot cases Z93 applied and tested at GSFC Coatings Lab Heater sizes updated based on thermal modeling results STATIC heater changed from 21 to 24W peak MAG heaters changed from 4.3W to 6.5W peak (each) power increase worked with the Project & S/C MAG sensor mounting bracket now built at GSFC Improve magnetics properties Mag sensor mounting bracket  designed, fabricated, and tested at GSFC EUV actuator status switch removed (caused sticking) EGSE sensor has been and will be used for ground testing FSW infers door status based on actuations All design changes documented, ICDs updated, and approved by CCB

  3. Plan Changes since CDR STATIC foil vibration screening added (complete) EM testing showed that screening eliminated foils poorly bonded to frames which then faired poorly in vibration Thermal Balance tests added to plan for MAG, SEP Thermal balance plan reviewed with thermal engineers from SSL, GSFC, and LM to identify which units require thermal balance to verify thermal models I&T Flow adjusted to optimize schedule keep package integration from slipping too far to the right SWIA, STATIC, SEP calibrations defered LPW FM preamp thermal vac deferred EUV environments moved forward

  4. Waivers & Deviations CCR082 against ERD, Instrument Interface not differential CCR135 against ERD, SEP grounding CCR231 against SOW, No structural math model for LPW CCR322 against MAR/MAIP/ERD, LTC1604 latchup testing CCR328, against MAR/MAIP, STATIC LVPS Derating Violation CCR405 against MAR/MAIP, SWEA Derating Violation CCR448, against MAR/MAIP, REG Derating Violation CCR408, against MAR/MAIP, DFB Derating Violation CCR432, against MAR/MAIP, BEB Derating Violation CCR464, against MAR/MAIP, DFB Derating Violation CCR407 against MAR/MAIP, soldering standard CCR484 against MAR/MAIP, PCB coupon rejection CCR493 against MAR/MAIP, skip transformer powered burn-in (*) CCR523 against MAR/MAIP, PCB coupon rejection (*) CCR545, against ERD, Connector carries signal and power (*) CCR334, Gold Rule 2.18, single connectors carry redundant functions CCR360, Gold Rule 2.07, no LPW boom deployment at spacecraft level All Approved by Project CCB except (*) The gold rule waivers were discussed at CDR One more potential gold rule waiver pending, 1000 operational hours at launch; some subsystems may not reach this. working with S/C Team to maximize run time during ATLO

  5. PFRs 34 Non-conformance Reports Items requiring rework but not repair. Record these on PFR forms 14 closed 17 PFRs requiring MRB Items requiring repairs such as white wires, but not associated with test failures, such as corrections to layout mistakes 3 closed; many waiting final sign-off 3 PFRs requiring FRB Items resulting from failures discovered in tests, typically resulting in damage to the item under test. One closed

  6. PFR List

  7. PFRs Requiring FRB PFR024, SWEA Intermittents See evidence of high voltage transients in vacuum 2-3 days after start of pump-down. No damage. Tracked down to air bubbles in staking material used on anode board near high voltage components FRB held Anode replaced with spare Closed, pending final signature PFR032 SWEA Damaged Major high voltage event caused by inadvertently leaving instrument powered on (including one section of high voltage) during pump-down. Damage to a number of parts. Analysis also indicates potential stress to other parts. FRB held All damaged and potentially stressed parts replaced and re-tested Closure pending parts failure analysis

  8. PFRs requiring FRB, cont. PFR052, REG FM1 Actuator Power Reversed Actuator power in REG board reversed Connector mis-wired Test proc did not include continuity check of power lines to active components Proc amended to add continuity test Power supply current-limit at 2A for ~2 seconds Proc amended to reduce current limit at initial turn-on 5 parts identified by analysis and test as potentially damaged FRB held 5/8, but PFR open pending fix, testing

  9. PFP Risks • 21 risks closed

  10. Risks List

  11. PFP Mass

  12. PFP Power SWEA, SWIA, LPW, MAG measured FM operational power Recent increase (4.8W orbit average) in MAG heater power, plus other small changes from thermal modeling ECR203 pending to increase PFP NTE heater power allocation Includes Adjustment to SEP thermal limits, CCR pending Reduces SEP heater power LM verifies heater power services can handle the load

  13. PFP Data Rate

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