FM1 Instrument Suite Pre-Ship Review (PSR)Magbooms- 1 UCB September 21, 2005 THEMIS FM1 INSTRUMENT SUITE PRE-SHIP REVIEW (PSR) MAGNETOMETER BOOMS Paul Turin Lead Mechanical Engineer University of California - Berkeley

FM1 Instrument Suite Pre-Ship Review (PSR)Magbooms- 2 UCB September 21, 2005 Summary of Current Mag Boom Status FM1 Configuration End Item Data Package ToC Requirements Fulfillment of Requirements PFR Status RFAs, Closeouts, Rework, etc. Appendices (testing info) Outline

FM1 Instrument Suite Pre-Ship Review (PSR)Magbooms- 3 UCB September 21, 2005 Requirements and Design: No change to (official) Requirements since MCDR Two changes to Boom design due to other considerations: –Tilt upwards 5 deg (FGM)10 deg (SCM) to reduce S/A shadowing –Required taller frangibolt towers, inclined pivots –Raise boom height above deck to clear higher solar array –Required raising shoulder bases on taller feet Several more changes needed to fix problems caused by 1 st two changes: –Strengthen SCM Frangibolt tower –Strengthen SCM Shoulder Feet Flexures –Replace FR-4 thermal isolators with steel blocks –Redesign shaft retention set screws Personnel, Assembly, and Test: 5 flight and 1 flight spare boom sets have completed functional and environmental testing and have been delivered to I&T. Force Reductions: –Booms are supported by LME on an as needed basis. Mag Boom Status

FM1 Instrument Suite Pre-Ship Review (PSR)Magbooms- 4 UCB September 21, 2005 Configuration Mag Boom Configuration by Serial Number: FM1 suite contains FM1 FGB and FM1 SCB The first “flight” unit was converted to FM6 (flight spare) due to ~1 hour of vibration testing incurred while sorting out problems caused by deployment angle and height above deck changes. Subsequent units all passed all tests first time.

FM1 Instrument Suite Pre-Ship Review (PSR)Magbooms- 5 UCB September 21, 2005 EIDP

FM1 Instrument Suite Pre-Ship Review (PSR)Magbooms- 6 UCB September 21, 2005 Mag Boom Requirements

FM1 Instrument Suite Pre-Ship Review (PSR)Magbooms- 7 UCB September 21, 2005 Satisfaction of Requirements Test Proof test of graphite tubes Ambient, 0 rpm deployment test Sine, Random Vibration test Ambient, 0 rpm deployment test Thermal vacuum test (cycling + Hot and Cold 1 st motion deployments) Ambient, 0 rpm deployment test 15 rpm equivalent drop test Repeatability test Torque margin test Mag alignment verification Length Measurement All test complete, all booms passed, all results in family (except FM6, still acceptable) Satisfies Requirement GEVS IN.BOOM_4 GEVS IN.BOOM_4 IN_BOOM_2,4 IN.BOOM_4 IN.BOOM_1 IN.BOOM_4 Science IN_BOOM_9,10

FM1 Instrument Suite Pre-Ship Review (PSR)Magbooms- 8 UCB September 21, 2005 PFR Status PFRStatusTitle PFR-025CLOSEDCracked feet in SCB frangibolt towerReplaced DAD Tower PFR-027CLOSEDCracked Base Bracket in SCBReplaced tower, used steel washers PFR-041CLOSEDSpring spool in SCB base hinge loosened by vibration. Tightened Spools with new tool to higher torque PFR-043CLOSEDDamaged threads in FGB frangibolt ring.Repaired thread with helicoil. Affects FM6 spare only PFR-044CLOSEDFriction increase in hinge mechanism after vibe Set screw backing out and binding – larger screw used and staked PFR-053CLOSEDIncreased base hinge friction post vib at qual levels Bronze on Al galling -- SS shim added for bronze bushing to ride on PFR-058CLOSEDSCB connector wire damageETU cable too short – Flight long enough PFR-073CLOSEDLength Discrepancy between SCM Flight Harnesses All cut to same length PFR-077CLOSEDFM1 FGB Fail to deploy in Cold Vacuum TestInadequate firing time for cold temperature – worked fine with correct time PFR-078CLOSEDCable for FGM Mag Boom is discoloredContamination analyzed by GSFC determined not a contamination hazard PFR-079CLOSEDFM2 FGB fails cold deployment 6/21/05Inadequate firing time for cold temperature – worked fine with correct time PFR-080CLOSEDFGB 2 fails cold deployment 6/22/06Frangibolts did fire, Operator forgot to remove tape holding booms together PFR-086CLOSEDIncorrect Deployment Angles in FGM DesignShims added to get correct angles

FM1 Instrument Suite Pre-Ship Review (PSR)Magbooms- 9 UCB September 21, 2005 RFAs, Closeouts, Rework, etc. No Mag Boom RFAs No remaining Closeout Items Rework or replacement of hardware: Flexure Feet replaced on SCM Set screw size increased and epoxied to prevent backing out Shims added to prevent galling Shims added to all units to correct deployment angle –Deployment and repeatability tests repeated on one unit to verify no problems Compliance with Test Verification Matrix Complete Test Margins Adequate margins at Deployment extremes Torque margin worst-case > 3.3 (reqmt >2) Survived vibration and thermal limits + margin Integration with Probe 1 Bus Per thm-mint-proc-026,-027,-037(currently in draft form) Units will get 1 st motion deployments during probe TV Changes requalified on FM6, and acceptance tested on all other units

FM1 Instrument Suite Pre-Ship Review (PSR)Magbooms- 10 UCB September 21, 2005 Appendix 1 Vibration Testing

FM1 Instrument Suite Pre-Ship Review (PSR)Magbooms- 11 UCB September 21, 2005 Vibration Testing Sine Vibration Levels (Ref. Swales SAI-TM-2430-RevD ) FM 6 tested to qual levels, FM 1-5 to acceptance levels

FM1 Instrument Suite Pre-Ship Review (PSR)Magbooms- 12 UCB September 21, 2005 Vibration Testing cont. Random Vibration Levels (Ref. Swales SAI-TM-2430-RevD ) FM 6 tested to qual levels, FM 1-5 to acceptance levels

FM1 Instrument Suite Pre-Ship Review (PSR)Magbooms- 13 UCB September 21, 2005 Vibration Testing Status

FM1 Instrument Suite Pre-Ship Review (PSR)Magbooms- 14 UCB September 21, 2005 Appendix 2 Themal Vac Testing

FM1 Instrument Suite Pre-Ship Review (PSR)Magbooms- 15 UCB September 21, 2005 Thermal Vacuum Testing -115C, 4h 75C, 4h -115C, 4h 75C, 4h 75C, 12h 50C, Hot Deploy -40C, Cold Deploy Restow Test temperatures and Profile:

FM1 Instrument Suite Pre-Ship Review (PSR)Magbooms- 16 UCB September 21, 2005 SCM/FGM Boom Thermal Testing Status

FM1 Instrument Suite Pre-Ship Review (PSR)Magbooms- 17 UCB September 21, 2005 Appendix 3 Strength, Repeatability, and Torque Margin Testing

FM1 Instrument Suite Pre-Ship Review (PSR)Magbooms- 18 UCB September 21, rpm and Repeatability Test Booms hung vertically and weighted so that 1g replicates loads caused by spin accelerations, then dropped from angle that gives correct energy at end of stroke to simulate 15 rpm deployment forces. Boom then dropped 5 times and the rest angles were measured, worst-case variations below.

FM1 Instrument Suite Pre-Ship Review (PSR)Magbooms- 19 UCB September 21, rpm and Repeatability Test continued Drop and repeatibility tests repeated on one unit with angle correction shims to show that shims (added per PFR-086) have no effect on repeatability or strength.

FM1 Instrument Suite Pre-Ship Review (PSR)Magbooms- 20 UCB September 21, 2005 Torque Margin test Ts Torque from Spring Tm Torque from Resistive Force on Force Gauge Tc Torque from Centripetal Force on Elbow Arm on Elbow Joint Tf Frictional Torque on Elbow Joint Minimum Torque Margin = 4.3 This test was run to verify adequate torque margin at worst-case joint at worst-case temperature of -8C and worst-case spin rate of 20rpm (bounce during thrust). Worst-case torque margin of 4.3 meets minimum requirement of 3