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Living With a Star Radiation Belt Storm Probes and Associated Geospace Missions D. G. Sibeck Project Scientist NASA Goddard Space Flight Center Geospace: Part of the Integrated LWS Plan Stereo Lead Solar Probe Stereo Lag Distributed network of spacecraft providing continuous observations of Sun-Earth system Solar and Heliospheric Network observing the Sun & tracking disturbances from the Sun to Earth Geospace Network uses a comprehensive set of spacecraft to diagnose the Geospace response Original Geospace Mission Concept • •Radiation Belt Storm Probes •Ionosphere-Thermosphere Storm Probes •UV Imager: O/N2 and Electron Density •SDO observations of EUV input The Radiation Belt Storm Probes Mission is in Phase A Formulation Launch 2012 Perigee: ~630 km altitude Apogee ~5.8 Re geocentric altitude Inclination ~10° Sun pointing, spin stabilized Duration 2 years (expendables 4 years) Radiation Belt Storm Probes – twin spacecraft in highly elliptical orbits to understand the basic principals behind relativistic particle acceleration, transport, and loss. Radiation Belts: Our Window on Fundamental Physics •Physics of the radiation belts are the physics of •Charge particle acceleration, transport, and loss. LWS Geospace RBSP Study Objectives • Source, loss, and transport processes • Shock-associated creation and decay of radiation belts; • Quantifying adiabatic and nonadiabatic processes; • ”Seed" or source populations; • Ring current and its effects on energetic particles; • Data assimilation and specification models --> for practical applications Mission Approach •Simultaneous two-point measurements by plasmasphere • identical spacecraft in common orbits. •with a slow separation in phase, 1 3 •lapping one another 4-5 times/year, •Covering the full range of local outer radiation times in 2 years. belt •Apogee of ~ 5.8 Re to sample 2 outer belt and ring current. •Perigee of ~ 630 km to sample inner belt. Precession Radial Profiles --> Distinguish Mechanisms •When closely spaced--> • determine radial phase space density gradients and discriminate between proposed source/loss regions and processes. Convection Radial Diffusion Local Acceleration Spatial Extent •When widely separated --> •measure spatial extent of ring current asymmetries and wave fields. Identify Source Populations •Measure ‘seed’ or source populations: Plasma sheet Substorm injected plasma Pre-existing relativistic particles Solar Energetic Particles. •and accelerated populations simultaneously. 4. Selected Investigations • NASA/HQ selected the following experiments: – ECT (Spence, Boston U.) Energetic Particle Composition and Thermal Plasma Suite – EMFISIS (Kletzing, U. Iowa) Electric and Magnetic Field Instrument Suite and Integrated Science – EFW (Wygant, U. Minnesota) Electric Field and Waves Instrument for the NASA RBSP Mission – RBSPICE (Lanzerotti, N.J. Inst. Technology) Radiation Belt Storm Probes Ion Composition Experiment • NASA entered into a partnership agreement with the NRO, who will supply: – RPS (Groves) Relativistic Proton Spectrometer The Radiation Belt Storm Probes: Particle Experiments The Radiation Belt Storm Probes: Field and Wave Experiments Three Missions of Opportunity in Competitive Phase A Study BARREL GOLD Robyn Millan Richard Eastes Dartmouth College U. Central Florida Balloon Array for RBSP Relativistic Electron Losses Global-scale Observations of Limb and Disk MORE Daniel Baker U. Colorado Boulder Mission of Opportunity RadBelt Experiment –Final reports due September 12, 2007 –Result could augment RBSP and/or IT science.