THEMIS MISSION PRE-SHIP REVIEW Vibration, Acoustics, & Spin Balance David Pankow

1. THEMIS MISSION • PRE-SHIP REVIEW • Vibration, Acoustics, & Spin Balance • David Pankow • University of California - Berkeley

2. GO FOR LAUNCH ! • … now how should I fill this 40 minutes

3. Overview • Topics Overview • 5-50 Hz Pre-Test of Probe Carrier with Mass Dummies • 5-50 Hz Test of Probe Carrier Assembly (Flight Probes) • MECO Transient Documentation • Acoustic Test of Probe Carrier Assembly • Spin Balance & Mass Properties of all Probes • PCA Spin Balance Planning for ASO

4. Vibrations Background • Probes were “Well Behaved” • Lateral Axes (X shown) • Most Q’s were < 15 • Probe antenna Q  25 • Thrust Axis (Z) • Q’s were mostly below 10

5. Vibrations Background • PCA was “Very Lively” • Lateral Axes (X shown) • Consistent with FEM & CLA • Top Probe Q  60-70 • “Twisting” Petals Q 20-30 • “Flapping” Petals Q 20-30 • All were Non-Linear • Crosstalk 1st Peaks  Input • Thrust Axis (Z) was “Quiet”

6. Sine Sweep • 5-50 Hz Pre-Test of Probe Carrier with Mass Dummies • Rationale: Not a required test, suggested by GSFC/AETD • Prior PSS Quals all between stiff plates, Petal Flex was a concern • Qual PSS was subjected Limit Load Sine Burst, strength should be OK • 80 kg Probes lack 50 kg Fuel in PCA test (insufficient loading) • Prior FEM indicated Petal “Twist Mode” was worst case • X direction PCA shake w/ QM PSS on Probe E Mass Dummy • PSS Loading Goal is 125% of FDLC RSS moment • Procs: Thm-mint-proc-049 rev 4; SAI-TM-3068; JPL-144-D-V-100261 • Test Report: SAI-TM-3068 to GSFC for review • Status: complete • Additional Information • Very Good Rehearsal for upcoming PCA test (after 8 tries) • Post Test QM PSS Pyro Release & Inspection - OK

7. PCA Sine Sweep • 5-50 Hz Test of Probe Carrier Assembly (Flight Probes) • Rationale: Required by NASA & Boeing • Often considered the “Dress Rehearsal” for Flight • Procs: Thm-mint-proc-049 rev 6; SAI-TM-3075 ;JPL-144-D-V-100261 • Report: SAI-RPT-788 to GSFC, KSC & Boeing for review • Status: complete • Additional Information follows • Quick Look Results • 1st MODES: • Top-26.5 Hz ; Petal Twist-31 Hz (pairs); Petal Flap-38 Hz (pairs) • PEAK LOADING GOALS: 125% of FDLC PSS RSS moment • (Top) A @ 86%; (Flap) B @ 94%; C @ 93%; (Twist) D @ 99%; E @ 96%

8. PCA Sine Sweep • 5-50 Hz PCA Sweep • Lateral Sine Sweeps • Data reflects PCA Behavior • Qtop ~ 60-70; Qpetals ~ 20-30 • No probe resonances in this range M+P Controller Tracking

9. MECO EVENT • MECO (main engine cut off) transient documentation • GOAL: document previous tests to projected MECO levels • 2 Stage Delta MECO Sine Input: 100-125 Hz @ 0.2g lateral; 0.5g axial • Opening Comments on Prior Test Data • Themis PCA showed NO MAJOR RESONANCES in this range • Any First Occurrence in our accumulated Test Data should be Adequate • Demonstration • Graphic “Quick Look” summary results & table on the subsequent pages • All Vibration testing raw “CSV” data is posted at: • ftp://apollo.ssl.berkeley.edu/pub/ME_Archives/Themis_I&T_procedures

10. MECO EVENT

11. MECO EVENT

12. MECO EVENT

13. MECO EVENT • STATUS: UCB draft to GSFC & KSC – KSC would like all boxes listed in this table

14. PCA Acoustics • Acoustic Test of Probe Carrier Assembly • Rationale: Required by NASA & Boeing • Procs: Thm-mint-proc-061; SAI-spec-1164; JPL-144-DA-100000 • Test Report: Thm-mint-rpt-061 to GSFC, KSC & Boeing • Status: complete • Additional Information Follows

15. PCA Acoustics Tabular Summary of Measured Responses Test Chamber Input

16. PCA Acoustics Response Plots:Solid – Random Input; Jagged – Acoustics Response

17. PCA Acoustics • SST Grms Response Compared • right: ETU random; 18.3 in / 42 response • below: P-2 random 4.43 in / 3.29 res. • below right: Acoustics 4.1 res. (P-1) 4.0 res. (P-5)

18. PCA Acoustics Boeing providedhardware NTE’s

19. PCA Acoustics Measured Extreme Peaks in Vibration & Acoustics Testing …from PER NEW DATA !

20. Probe Spin Balance • Spin Balance & Mass Properties of All Probes • Rationale: Science Rqm’t: CG < 0.18” ; PA offset < 1 • Procs: Thm-mint-proc-049; SAI-plan-0731; ManTech-09PC-WI58 Rev.4 • Reports: ATAC-23-15-7628 (ManTech); Thm-mint-rpt-049 (UCB) • Status: complete • Additional Information Follows • Common Set of Balance Masses & Mass Properties was Adequate • FOT will need to Track Fuel Use, as Previously Planned

21. Probe Spin Balance • Mag Boom Simulator Masses Review • Static Balance drives X,Y cg to 0,0 • Dynamic Balance drives Lateral POIs (Ixz, Iyz) to zero • Find a set of masses that make the MB’s look deployed • All other measured mass properties have to be corrected • Independent Solutions by 3D CAD & 1st Principals • Solid Works model used for MB parts fabrication, reviewed by G.Dalton • Excel model assembled a set of point & distributed masses (ftp posted) • Continued Validation Efforts • Mass information checked against Build Logs • Locations (dimensions) from Probe CMM data & MB deployment tests • Swales agrees with our methods (but can’t vouch for our first hand data) • AXB’s & SPB’s use this same mass & dimension approach • Lateral POI’s are the “new wrinkle” for the Mag Booms.

22. Probe Spin Balance

23. Probe Spin Balance • On Orbit Spin Axis Uncertainties

24. ASO Spin Balance • PCA Spin Balance Planning • Rationale: Required by Boeing for STAR-48 1 Hz Spin • Static Balance < 0.05 inch • Dynamic Balance < 1/4 (P.A. offset) • Procs: Thm-mint-proc-067; SAI-plan-0794; ASO-M0006 rev A • Status: ASO’s proc is long standing, UCB proc in draft form • Additional Information: no identified issues • Adaptor Plate & Balance Mass Kit are both In-house