We are a spacefaring society, ever reliant on space technologies and on the threshold of manned space exploration. However, the space environment is harsh to both machines and astronauts. In coming decades, the multi-billion-dollar satellite industry will grow substantially. Most satellites orbit at high altitudes in the radiation belts, a dynamic region where energetic electrons and ions are trapped in Earth's magnetic fields also known as the "magnetosphere". Even the low-altitude International Space Station orbit skims the radiation belts, posing serious concerns to astronaut safety. As noted by NASA's Living With a Star Geospace Mission Definition Team: "Understanding the radiation belt environment and its variability has extremely important practical applications in the areas of spacecraft operations, spacecraft and spacecraft system design, and mission planning and astronaut safety."(1) In order to protect satellites and astronauts from high energy radiation and other adverse effects, it is essential to understand first how energetic charged particles are accelerated, transported, and lost in Earth's radiation belts.

The Radiation Belt Storm Probes (RBSP) - Energetic Particle, Composition, and Thermal Plasma (ECT) suite contains a well-proven complement of particle instruments to ensure the highest quality measurements ever made in the inner magnetosphere. The coordinated ECT particle measurements, analyzed in combination with fields and waves observations and state-of-the-art theory and modeling, are necessary yet sufficient for understanding the acceleration, global distribution, and variability of radiation belt electrons and ions, key science objectives of NASA's Living With a Star program and the RBSP mission.

The RBSP-ECT suite consists of three highly-coordinated instruments (MagEIS, HOPE, and REPT) that cover comprehensively the full electron and ion spectra from one eV to 10’s of MeV with sufficient energy resolution, pitch angle coverage and resolution, and with composition measurements in the critical energy range up to 50 keV and also from a few to 50 MeV/nucleon. All three instruments are based on measurement techniques proven in the radiation belts, optimized to provide unambiguous separation of ions and electrons and clean energy responses even in the presence of extreme penetrating background environments. The ECT team applies our extensive experience in designing, fabricating and operating spaceflight instrumentation in the harsh RBSP radiation environment to ensure that ECT particle measurements have the fidelity needed to answer key RBSP science questions.

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Reference: (1) The LWS Geospace Storm Investigations - Exploring the Extremes of Space Weather, Report of the Living With a Star Geospace Mission Definition Team, NASA/TM—2002—211613, September 2002. http://lws.gsfc.nasa.gov/documents/geospace/geospace_gmdt_report.pdf