15-1 MAVEN IPER May 22-23, 2012 Particles and Fields Package Pre-Environmental Review May , SWIA (Solar Wind Ion Analyzer) J.S. Halekas and the SWIA Team Mars Atmosphere and Volatile EvolutioN (MAVEN) Mission

15-2 MAVEN IPER May 22-23, 2012 SWIA PER Outline I.Overview II.Test Results III.Vibration Plans IV.Thermal Vacuum Plans

15-3 MAVEN IPER May 22-23, 2012 SWIA Integration Status & PFR Status SWIA FM build nearly complete –PWB Stake/Coat In Process (Anode Board Already Done) PFRs & NCRs all resolved –Wrong gender on Preamp MDMs (NCR) Fixed by re-routing pigtails –Lifted-up resistor pads on SWEEP Fixed with epoxy –Added Resistors on SWEEP Added resistors to fix deflector settling time –Analyzer exit grid tolerance stackup (NCR) Fixed by reworking hemisphere mount –Anode/Analyzer outer diameter mate (NCR) Fixed by reworking outer EMI closeout –MCP Imon MUX saturation possible (NCR) Fixed by changing divider in circuit –Timing slip for last message of cycle (NCR) Instituted operational workaround –Several DCB parts installed too high (NCR) Plan to stake them –Preamp annular gap around pins (NCR) Fixed layout

15-4 MAVEN IPER May 22-23, 2012 SWIA Test Status EM Testing completed after CDR –EM Attenuator thermal/life tests –EM Sensor Calibration FM Component Level Testing Completed –Board Level tests of all 5 FM boards, plus flight spare Anode FM System Level Testing Completed –Integrations: DCB/LVPS, DCB/LVPS/Preamp, DCB/LVPS/SWEEP, final integration with all 5 boards on bench, then in instrument –Product tests and threshold testing with DCB/Preamp/Anode –First functional and calibration completed in small calibration chamber Final calibration in big chamber after environments –Thermal cycle of FM LVPS/DCB/PreampMCP + spare Anode Comprehensive Performance Test Completed –First SWIA Instrument CPT Complete PFDPU Integration and PF CPT after stake/coat

15-5 MAVEN IPER May 22-23, 2012 SWIA Resource Update Power With HV On, Not Sweeping: 1.62 W Total Power While Sweeping (Room Temp): Min 1.62 W, Max 2.52 W, Cycle Average 1.75 W (<1.93 CBE) +7.5mW/MHz/channel=> ~1.92 W at peak rates Min: 58 mA, Max 90 mA Mean 62 mA kg (-60 g savers, +stake/coat) < 2.67 CBE

15-6 MAVEN IPER May 22-23, 2012 SWIA FM Board Test GSE Digital+Preamp+Anode MISG in PFDPU Mode GSEOSLaptop CalibratedScope LVPS SWEEP CalibratedPowerSupplies GSE Cables SWIA Deconstructed!

15-7 MAVEN IPER May 22-23, 2012 SWIA FM Board Tests Fully tested functionality of all boards, separately and integrated together in various configurations Standard Product Test: Threshold Scan w/ Test Pulser Run in Many Configurations, as part of Many Tests MCPHV Control Voltage SWEEP Control Voltage Also, settling time, stability, ripple, etc. P0 P1 P2

15-8 MAVEN IPER May 22-23, 2012 SWIA FM System Level Test Facilities Instrument operation in chamber uses same GSE as board testing, with extender harnesses through the chamber wall Three-axis manipulator allows full scan of FOV w/ stationary ion source in chamber Old Chamber New Chamber EM on Manipulator IonBox CleanRoom

15-9 MAVEN IPER May 22-23, 2012 Raw HV SWIA FM CPT Complete Verify Aliveness L ✔ Verify Housekeeping L ✔ Verify Data Products L ✔ Run Test Pulser to Verify Products L ✔ Run Threshold Sweep to Characterize Noise Level L ✔ Test S/C controlled Heater/Temp Sensor (A&B sides) ✔ Open Top-cap with S/C Controlled Actuator (A&B sides) ✔ Test Attenuator ✔ Verify High Voltage Operation ✔ Test Memory L ✔ Power Down L ✔ Reset Actuator ✔ (*) Purge and/or vacuum required L Also Part of LPT Analyzer Sweep Products w/ Test Pulser P1 P2 Heater Test Reference: MAVEN_SWI_PROC_036_Instrument_CPT MAVEN_PF_TP_054_SWIA_LPT

15-10 MAVEN IPER May 22-23, 2012 SWIA Trending Values for I&T/ATLO Housekeeping Values –Digital and Analog Voltages With (if configuration allows) and without HV enabled and ramped up Instrument Power Draw –With (if configuration allows) and without HV enabled and ramped up Background Count Rates –At nominal preamp thresholds 0x9500 –With (if configuration allows) and without MCP HV on and ramped up To get intrinsic instrument electronic background (effectively zero) & channel plate background (~10 c/s for whole instrument)

15-11 MAVEN IPER May 22-23, 2012 SWIA FM Initial Calibration Results Model Data Model Data Contours = Simulation Color = Measured Response Analyzer Response < 1.5% Off From Simulation Variation <2% Around Analyzer Hemispheres Located & Concentric to Within 30μ (~1 mill) Verifies PF72 Verifies PF74 Concentricity Scan

15-12 MAVEN IPER May 22-23, 2012 SWIA FM Initial Calibration Results Energy Scan: 5 kV to 20 eV Phi Scan: Full 360 degrees Theta Scan: -18 to +18 degrees (Will do wider scan in big chamber) 22.5° Anodes 4.5° Anodes One-Time Low Energy Measurement Verifies PF73 Verifies PF75, PF77 All Verify PF76 (*) Hand Scan, Non-Uniform Rate

15-13 MAVEN IPER May 22-23, 2012 SWIA FM Initial Calibration Results Attenuator works perfectly as designed Provides ~15x attenuation over +/-45 degrees –Smooth roll-off allows some pickup ion measurements simultaneously w/ intense solar wind Phi Scan: Attenuator Open Phi Scan: Attenuator Closed Open Closed (*) Hand Scan, Non-Uniform Rate

15-14 MAVEN IPER May 22-23, 2012 REQUIREMENTSWIA DESIGNVerification PF72: SWIA shall measure energy fluxes from 1x10 7 to 1x10 10 eV/(cm 2 s sr eV) with no worse than 25% precision Compliance. SWIA designed to measure energy fluxes from 5x10 4 to 7x10 11 eV/(cm 2 s sr eV) Verified: Calibration/ Simulation PF73: SWIA shall measure ion flow velocities from km/s Compliance. SWIA designed to measure energies from 5 eV – 25 keV and thus ion flow velocities from km/s Verified: Calibration PF74: SWIA shall have energy resolution dE/E at least 15% Compliance. SWIA designed to have energy resolution of 15% Verified: Calibration PF75: SWIA shall have angular resolution of at least 30° (10° in Sun direction) Compliance. SWIA designed to have angular resolution of 22.5° (4.5° in Sun direction) Verified: Calibration PF76: SWIA shall have time resolution of at least 1 minute or better Compliance. SWIA designed with intrinsic time resolution of 4 seconds. Verified: Calibration PF77: SWIA shall have a FOV of 180x40° or better Compliance. SWIA designed to have a FOV of 360x90° Verified: Calibration PF106: SWIA shall have an in-flight calibration procedure to determine its absolute sensitivity to within 25%. Compliance. Inflight Calibration Plan PF_SYS_35 written in response to CDR RFA Verified: PF_SYS_35 SWIA PF Level 3 Requirements Reference: MAVEN_PF_SWIA_009b_Calibration_Plan ✔ ✔ ✔ ✔ ✔ ✔−✔− ✔

1-15 MAVEN CDR May 23-25, 2011 SWIA Final Calibration Final SWIA Calibration still required –All PF Level 3 requirements have been verified, or could be verified with analysis of calibration data conducted to date The FM instrument works and will meet requirements –To fully characterize the instrument, we need to conduct a final calibration in the big chamber, where we can yaw to +/-45 Can only yaw +/-18 in the small chamber: This could be used together with simulation/analysis to verify +/-20 requirement, but we prefer to directly verify the requirement, and fully characterize the FOV –This also serves the purpose of ensuring that nothing in the optics or any electrical connections are affected when boards are removed for stake/coat and then replaced Final Calibration will take place after environments –(Or before PF I&T if stake/coat finishes quickly) –Low risk of any result that would require a repeat of environmental tests, given initial calibration results

15-16 MAVEN IPER May 22-23, 2012 SWIA Attenuator Test Flow Calibrations & Environments: Limited Actuations (<50) Calibrations & Environments: Limited Actuations (<50) Characterize Actuation Hot and Cold Life Test (4100 cycles, 2x expected) Characterize Actuation Hot and Cold Life Test (4100 cycles, 2x expected) SWIA FMAttenuator SWIA FM Attenuator Reference: MAVEN_PF_TP_051_STATIC_Attenuator_Test

15-17 MAVEN IPER May 22-23, 2012 Limited Life Testing Attenuator Mechanism –EM unit life tested Tested to >12,000 cycles –Spare FM unit built for characterization over thermal limits, life testing etc. Test to > 4,100 cycles –Instrument FM attenuator actuations tracked Expected actuations: 50 on ground, 2,000 in orbit Actuations so far: 14 (10 in mechanism checkout, 2 in CPT, 2 in initial calibration) One-Time-Cover Release Mechanism –EM unit tested 16x to verify durability (Good for 100 cycles according to manufacturer) –FM cover firings tracked Expected openings: 7 on ground, 1 in orbit Cover openings so far: 2 (A&B side circuit tested in instrument CPT)

15-18 MAVEN IPER May 22-23, 2012 SWIA Vibration Plans SWIA will be vibrated at the same facility as the EM EM was vibrated with one EM board to test two staking schemes for A121 preamplifiers (both successful) SWIA EM Vibe Purged & Bagged (cutouts for accelerometers) Reference: MAVEN_PF_TP_047_SWIA_Vibration_Test

15-19 MAVEN IPER May 22-23, 2012 SWIA TVAC Configuration Cover Mon/ Thermister SWI-J4 Enable Plug SWI-J2 GSEOS PC MISG BOX NETGEAR TVAC Chamber SWIA Cover/Heater Relay Box 28V Power Supply SWI-J1 SWI-J5 SWI-J3 28V Power Supply Attenuator I/F MGSE EGSE Flight HW Adapter Plate Ion Box KEY: Power Supply TQCM Note: some portion of TVAC HV Test will include interface to EM PFDPU outside chamber.

15-20 MAVEN IPER May 22-23, 2012 SWIA TVAC Cycles Cycle Number: 1 LPT CPT Bake-Out LPT CPT Open Cover, Test Atten Open Cover, Test Atten Break Vacuum: Reset Cover, LPT Reconfigure to I/F to EM PFDPU HV On. Ion Box On HV On, Ion Box On LPT Cold Start, Heater Test Hot Start CPT

15-21 MAVEN IPER May 22-23, 2012 TVAC Functional Plan NB: Currently Survival and Operating are the same value for both Hot and Cold. Limited thermal balance requires no extra cycles or change in configuration. Reference: MAVEN_PF_TP_048_SWIA_Thermal_Vacuum_Test