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SPACECRAFT OVERVIEW/STATUS Peter R Harvey THEMIS Project Manager. 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.
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SPACECRAFT OVERVIEW/STATUS • Peter R Harvey • THEMIS Project Manager
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 : Ground Based Observatory Probe conjunctions along Sun-Earth line recur once per 4 days over North America. … while THEMIS’s space-based probes determine onset of Current Disruption and Reconnection each within <10s. Ground based observatories completely cover North American sector; can determine auroral breakup within 1-5s …
Mission Overview Launch 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 Transponder Fuel Tank 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 ofremaining 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
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
Geographic Longitude 195° Geographic North Pole Geographic Longitude 324° Geomagnetic NorthPole Courtesy H.Frey, UCB Ground Based Observatories • 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
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
Probe Processing Delivery to ASO Bolt Cutter Installation Solar Array Illumination Performance Tests
Probe Fueling Vibration Acoustics Spin Balance Dry Weigh & Pressurize Fueling Thermal Vacuum Storage
PCA Processing Final checks Acoustics Spin Balance PCA Integration SSS Installation Ready for Probes Vibration Fairing Installation Storage Spin Balance
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