THEMIS MRRSystems - 1 GSFC, Jan 5, 2007 Systems Engineering

THEMIS MRRSystems - 2 GSFC, Jan 5, 2007 Design Mission Description Instrument and Probe Configuration Launch and Mission Description Requirements Verification Summary, Waived and Pending Requirements New Mission Profile Review Resources Operating Hours Problem Failure Reports Statistics and Status Unverifiable Failures Operational WorkArounds Systems Agenda

THEMIS MRRSystems - 3 GSFC, Jan 5, 2007 Launch Vehicle:Delta II, Eastern Range Apogee: km ± 9567 km Perigee:435 km ± 10 km (500 km ± 7 km on or after 3/1/2007) Inclination:16.0 deg ± 0.5 deg Date:February 15, 2007 Space Segment Spacecraft:5 Spinning Probes with Fuel for Orbit & Attitude Adjust Instruments:3-Axis Electric Field, Magnetic Field 3-D Ion & Electron Particle Detectors Spin Rate:20 RPM Orbit Period(s):1, 2 and 4 days Orientation:Ecliptic Normal Ground Segment Observatories:20 Northern with All Sky Imagers and Magnetometers Control Facilities:Mission and Science Operations Centers Operations Phases:L&EO, Cruise, Ascent, Campaigns, De-orbit Lifetime:2.3 years Mission Summary

THEMIS MRRSystems - 4 GSFC, Jan 5, 2007 Instrument Configuration IDPU: Instrument Data Processor Unit SPB : Spin Plane Booms (4x) AXB : Axial Booms (2x) SST : Solid State Telescope (2x) ESA : Electrostatic Analyzer FGM : Fluxgate Magnetometer SCM : Search Coil Magnetometer

THEMIS MRRSystems - 5 GSFC, Jan 5, 2007 Fuel Tank ESA EFI SPB Thruster T1 EFI Axial Booms (2, Stowed) Battery BAU Repress Tank Miniature Sun Sensor Transponder Thruster T2 IDPU Fuel Tank Antenna EFI SPB Thruster A1 Thruster A2 AEB Gyros Probe Configuration

THEMIS MRRSystems - 6 GSFC, Jan 5, 2007 Standard Delta 10 ft. Fairing Static Envelope 3712 PAF Probe Carrier Assembly (PCA = 5 Probes + Probe Carrier) on L/V Probe Carrier Assembly (PCA = 5 Probes + Probe Carrier) on L/V THEMIS Launch Configuration Probe Carrier Assembly (PCA) on Delta 3 rd Stage Launch Configuration Dedicated launch accommodated within standard Delta vehicle configuration and services 10’ Composite Fairing required to accommodate five Probes on the Probe Carrier in the “Wedding Cake” configuration PC stays attached to Delta 3 rd stage after probe dispense Each probe dispense from the PCA is coordinated with but independent of the other probes No single probe anomaly precludes dispense of remaining probes Star 48 3 rd Stage

THEMIS MRRSystems - 7 GSFC, Jan 5, 2007 Mission Profile

THEMIS MRRSystems - 8 GSFC, Jan 5, 2007 Mission Requirements Documentation (MRD) THM_SYS_001K_MRD.xls Mission Requirements Verification 476 Requirements total 467 Requirements verified 5 Requirements pending 4 Requirements waived Requirements Status

THEMIS MRRSystems - 9 GSFC, Jan 5, 2007 Implementation Change IN.ESA-08: ESA Dayside Energy Flux Attenuator Waived: Electronic Counting Was Fast Enough IN.DPU-09: Stored Housekeeping Telemetry Storage Waived: BAU saves all IDPU Engineering Data As Measured IN.EFI-11: EFI Noise Level < 1 x 10^-4 mV/m/sqrt(Hz). Waived: EFI measured noise level is 2 to 3 x 10^-4 mVm/sqrt(Hz). PC.Mech-1: Probe-to-Probe Static Clearance of 4 inches Waived: Current static clearance is 3.75 inches. Requirements Waived

THEMIS MRRSystems - 10 GSFC, Jan 5, 2007 Launch Site Verification M-33 Electrostatic Cleanliness requirement verification pending ESC survey after all flight close-outs (Jan 9) M-45, M-47, PC-8 PCA Mass Properties (Mass, CG, and Principle Misalignment) requirement verification pending PCA Spin Balance Test and final weighing of PCA with fueled Probes. (Jan 12 and 13) Post-Launch Verification IN.ESA-13 ESA On-Orbit Calibration requires raw data to be collected prior to final coefficients to be delivered to the Science Operations Center. (March 2007) Requirements Pending

THEMIS MRRSystems - 11 GSFC, Jan 5, 2007 Mission Profile Review for Feb 15, 2007 Launch EFI Boom Deploy delayed ~ 9 months on Probes 1 & 5 –THEMIS Deployment Motors Life Test (21 50 C) –CLUSTER lifetime tests also relevant and showed no issues RCS Re-pressurization delayed about 6 months –No Issues with RCS Components –Cassini waited several years to do the recharge. Ascent Maneuvers Delayed appx 6 months –Increased IRU radiation qualification to 63 Krad (RDM of 2) Power considerations –Improved launch orientation, side solar arrays in sun. –No change in number or duration of eclipses Thermal environment –No change New Mission Profile

THEMIS MRRSystems - 12 GSFC, Jan 5, 2007 Mass Status < 2% mass deviation between Probes (requirement) Dry Mass Margin: 4.5% (Worst case) Power Status Probe CBE: 38.7 W Probe Capability: W Probe Margin: 8.8% (First 3-hour Eclipse Season) 4.9% (Second 3- hour Eclipse Season) Resources

THEMIS MRRSystems - 13 GSFC, Jan 5, 2007 Integrated Probe Hours: Components : Averaged 780 hours run time prior to integration. Failure Free Hours: Hours accumulated on core system after return of transponder and BAU during mission integration. Late Instrument Swaps (>100 hours gained on integrated system after all swaps): Spare SST on F1 swapped in prior to TVac in August Spare SCM on F1 swapped in early October EFI re-work on F1-F5 completed in November Thermal Vacuum Hours: failure free hours were accumulated on all components during Probe Level TVac. Components accumulated and average of 250 hours during Component Level TVac. Operating Hours

THEMIS MRRSystems - 14 GSFC, Jan 5, 2007 PFR Statistics (All Spacecraft) Total : 237 Closed : 237 Open: 0 Unverifiable Failures : 13 Operational Work-Arounds : 10 Problem/Failure Reports

THEMIS MRRSystems - 15 GSFC, Jan 5, 2007 Unverifiable Failures

THEMIS MRRSystems - 16 GSFC, Jan 5, 2007 Operational WorkArounds