Progress towards achieving Level-1 Requirements NASA/GSFC, Oct 26, 2007

1. Progress towards achieving Level-1 Requirements NASA/GSFC, Oct 26, 2007

2. Science ObjectivesNote: Primary Science is sole Mission Design Driver • THEMIS HAS FOCUSED MINIMUM (TO BASELINE) OBJECTIVES: • Time History of Events… • Auroral breakup (on the ground) • Current Disruption [CD] (2 probes at ~10RE) • Reconnection [Rx] (2 probes at ~20-30RE) • … and Macroscale Interactions during >5 (>10) Substorms (Primary): • Current Disruption and Reconnection coupling • Outward motion (1600km/s) of rarefaction wave • Inward motion of flows (1000km/s) and Poynting flux. • Ionospheric coupling • Cross-tail current reduction (P5u/P4) vs flows • Field aligned current generation by flow vorticity, pressure gradients (dP/dz, dP/dx). • Cross-scale coupling to local modes • Field line resonances (10RE, 5 min) • Ballooning modes, KH waves (1RE, 1min) • Weibel instability, cross-field current instability, kinetic Alfven waves (0.1RE, 60Hz) • Production of storm time MeV electrons (Secondary) • Control of solar wind-magnetosphere coupling by the bow-shock, magnetosheath and magnetopause (Tertiary) Placement TBD

3. EFIs EFIa SCM ESA SST FGM Tspin=3s Instruments required: Redundancy and Overlap 1 FGM: Low freq. B-field (0-64Hz) 1 ESA: Thermal plasma2 SSTh (heads): Super-thermal plasma1 SCM: High freq. B-field (1Hz-4kHz) 4 EFIs (spin plane) & 2 EFIa (axials): Low&High freq. E-field Deployment TBD

4. Level 1 Science Requirements • Progress Towards Meeting Science Requirements • The THEMIS team, through its current science analysis, has demonstrated complete and flawless instrument operation from all operational spacecraft instruments and ground based observatories • Exception (non L1 threatening): Two GBO ASIs: • KIAN (Kiana, Western Alaska) • NAIN (Eastern Canada, currently in deployment) • Only one GBO magnetometer per hour of Magnetic Local timeis required to meet the baseline objectives (per L1 requirements document) • Data products required for L1 req’s are currently being generated • Baseline mission success still requires: • 1. Probe alignments for 188hrs/yr • Expected to be in position by early November • End-to-End Mission design runs demonstrate >250hrs/yr • 2. The deployment of at least one pair of EFI spin plane booms on P1 • Slated for Nov 3rd • All other boom pairs (6 out of 6) have been deployed flawlessly • All EFI instruments are returning good quality data • We expect that THEMIS instruments, data return and data processing shall have no problem meeting the THEMIS Level 1 Requirements

5. Specific L1 Science Requirements • Baseline science • Use array of ground magnetometers (2/MLT hour) and ASI (1/MLT hr) in North America to determine within < 30s and 1° longitude the time and location of substorm onset. Verified by March 23, 2007 substorm event. • Use two near-equatorial probes 8-10 RE from Earth to determine time and location of current disruption. Awaiting February 2008 alignment of spacecraft in magnetotail. • Use two near-equatorial probes 20-25 RE from Earth to determine time and location of magnetotail reconnection. Awaiting February 2008 alignment of spacecraft in magnetotail. • Obtain simultaneous observations of substorm onset and meridian (ground), current disruption and and reconnection for >10 substorms. Method validated by study of March 23, 2007 substorm. • Use the probes to track sunward moving flows and tailward moving rarefactions. Method validated by study of March 23, 2007 substorm dipolarization. • Determine radial and cross-tail pressure gradients and plasma flows. Awaiting alignment during February 2008. • Determine the change in cross-tail current at current disruption. Awaiting alignments during February 2008. • Distinguish between MHD and non-MHD components of the plasma flow. Demonstrated by work of J. McFadden (comparisons of ExB and V)

6. Specific L1 Science Requirements • Baseline science • Determine the characteristics of field line resonances, Kelvin-Helmholtz waves, and ballooning waves. (TBD in tail). • Determine the presence of cross-field current instabilities. (TBD in tail). • Determine the source and acceleration mechanisms for for storm-time MeV electrons (TBD during storm time tail excursions). • Determine the nature and cause of magnetopause transient events. Validated by ongoing studies of (1) boundary waves, (2) flux transfer events, and (3) hot flow anomalies in the foreshock.

7. Mission and Spacecraft Requirements • Instruments and Spacecraft shall be designed to last 2 years • Spacecraft now completing 9th month of operations • The spacecraft will have a 3-s spin period. • Current spin period is 3s.

8. Level 1 Ground System Requirement • The THEMIS Ground Data System shall capture and process a daily average of 1 Gbyte. • Demonstrated during last Winter season

9. Level 1 Mission Data Requirement • Validated and calibrated data shall be made publicly available within 6 months of the observation. • Survey plots available on-line from UCB within 2-3 days • Plasma moments, energetic particle distributions, and E/B/wave field observations delivered to SPDF within 1 day. High resolution (3s) plasma moments during fast survey mode will be delivered within 2 weeks. • Science analysis software used by the team will be made available to the public. • All analysis software is publicly available from the UCB WWW site. • Data Management Plan • THEMIS team working closely with both VMO’s and SPDF to ensure easy access to THEMIS observations by broad community. • THEMIS team defining parameters in SPASE terminology with assistence of VMO teams.