SPACECRAFT OVERVIEW/STATUS Peter R Harvey THEMIS Project Manager

Flight Systems Overview Ground Systems Overview Agenda Mission Objectives Flight Systems Overview Ground Systems Overview Ground Based Observatories Overview Major Reviews and RFAs Current Status / Open Work Issues Summary

Mission Objectives Probe conjunctions along Sun-Earth line recur once per 4 days over North America. Ground based observatories completely cover North American sector; can determine auroral breakup within 1-5s … … while THEMIS’s space-based probes determine onset of Current Disruption and Reconnection each within <10s. : Ground Based Observatory

Mission Overview Launch Space Segment Ground Segment Operations Vehicle: Delta II, Eastern Range Apogee: 91845.2 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

Instrument Overview 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

Probe Overview Antenna EFI Axial Booms (2, Stowed) ESA Miniature Sun Sensor Fuel Tank IDPU EFI SPB Repress Tank Fuel Tank Transponder Thruster A2 Thruster T1 EFI SPB Thruster A1 BAU Battery Gyros EFI SPB Thruster T2 AEB

Launch Configuration Dedicated launch accommodated within standard Delta 7925-10 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 3rd 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 Standard Delta 10 ft. Fairing Static Envelope Probe Carrier Assembly (PCA = 5 Probes + Probe Carrier) on L/V 3712 PAF Star 48 3rd Stage Probe Carrier Assembly (PCA) on Delta 3rd Stage THEMIS Launch Configuration

Ground System Overview Ground System Elements Ground Stations Ground Network Space Network Mission Operations Center Science Operations Center Flight Dynamics Center Including Mission Design Orbit & Attitude Determination Maneuver Planning Limit Detection and Notification Network Security

Mission Operations Center BGS Antenna, Equipment Racks and FOT Workstations at the Mission Operations Center

Secondary TLM/CMD/TRK Ground Stations Mission Supported by 5 Ground Stations Ground Stations: BGS, WGS, MILA, AGO, HBK GN, SN and FDF Support Documented in PSLA All Stations Have Successfully Flowed Data with MOC Ground Station Station Designator Figure of Merit Location Function Berkeley, CA BGS 11-m 24.0 dB/K 37.879° N 122.243° W Primary TLM/CMD/TRK Wallops Island, VA WGS 11-m 23.0 dB/K 37.925° N 75.476° W Secondary TLM/CMD/TRK Merritt Island, FL MILA 9-m 1/2 21.6 dB/K 28.508° N 80.693° W Santiago, Chile AGO 9-m 33.151° S 70.668° W Hartebeesthoek, SA HBK 10-m 20.4 dB/K 25.883° S 27.708° E

Mission Profile 81

Ground Based Observatories UCB has Delivered All 20 GBO (GMAG and ASI) units 19 Have Been Installed, 1 Needs Repair Automatic Data Collection and Archiving in Progress Remote Commanding and Diagnostics Working Expect to be Fully Functional at Winter 2008 Courtesy H.Frey, UCB Geographic Longitude 324° Longitude 195° Geomagnetic North Pole

Major Reviews

Final Two Closed since MRR RFA Status IIRT Reviews IIRT Performed 27 Formal Reviews of THEMIS IIRT Issued 308 RFAs and Recommendations Project Completed & IIRT Concurred on all 308 Final Two Closed since MRR RCS Proof Launch Window Analysis SMSR RFAs Provide update on NROL-21 FOD Issue Assess Issues with L3 Across Agency MRB RFAs Complete Launch Window Analysis Update/Provide First Contact Timeline

Current Status/Open Work

Solar Array Illumination Probe Processing Delivery to ASO Bolt Cutter Installation Performance Tests Solar Array Illumination

Probe Fueling Vibration Acoustics Spin Balance Dry Weigh & Pressurize Thermal Vacuum Storage

PCA Processing Final checks Acoustics Spin Balance PCA Integration SSS Installation Ready for Probes Vibration Fairing Installation Spin Balance Storage

Issues Bolt Cutter Thermal Tape PCA Separation System Bolt Cutters Only Partially Taped Concern Bolt Cutter Temp Would Exceed 160F Allowable Access to Cutters Posed Some Risk to Payload ULA Reran Thermal Analysis for Feb 15 to Mar 15 2007 Predict Max Cutter Temperature of 100F Concluded “as installed” is acceptable for flight. Payload Concurred

Summary Issues Bolt Cutter Taping – Use as Is P1115 Connector Demated – Closed PCA-3rd Stage CG Offset – Closed Summary Status Probes and Probe Carrier are Flight Ready Mission Operations is Complete Launch Team and Operations Teams are Ready Readiness Statement THEMIS is Ready to Continue Processing for Launch