Science Goals and Overview of the Radiation Belt Storm Probes (RBSP) Energetic Particle, Composition, and Thermal Plasma (ECT) Suite on NASA’s Van Allen Probes Mission

TLDR

All three instruments are based on measurement techniques proven in the radiation belts. The paper outlines the RBSP‑ECT science objectives, instrument capabilities, data collection, and early results to support understanding of radiation belt dynamics. The RBSP‑ECT suite comprises three coordinated instruments—MagEIS, HOPE, and REPT—that together provide continuous coverage of electron and ion spectra from 1 eV to tens of MeV with high resolution, pitch‑angle coverage, and composition measurements up to 50 keV and 50 MeV/nucleon, using proven techniques and innovative designs optimized for extreme radiation belt conditions. Early mission results demonstrate the suite’s capability to capture radiation belt dynamics. ECT instrument details are provided in companion papers in this issue.

Abstract

The Radiation Belt Storm Probes (RBSP)-Energetic Particle, Composition, and Thermal Plasma (ECT) suite contains an innovative complement of particle instruments to ensure the highest quality measurements ever made in the inner magnetosphere and radiation belts. The coordinated RBSP-ECT particle measurements, analyzed in combination with fields and waves observations and state-of-the-art theory and modeling, are necessary 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 Van Allen Probes mission. The RBSP-ECT suite consists of three highly-coordinated instruments: the Magnetic Electron Ion Spectrometer (MagEIS), the Helium Oxygen Proton Electron (HOPE) sensor, and the Relativistic Electron Proton Telescope (REPT). Collectively they cover, continuously, 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. The instruments use those proven techniques along with innovative new designs, optimized for operation in the most extreme conditions in order to provide unambiguous separation of ions and electrons and clean energy responses even in the presence of extreme penetrating background environments. The design, fabrication and operation of ECT spaceflight instrumentation in the harsh radiation belt environment ensure that particle measurements have the fidelity needed for closure in answering key mission science questions. ECT instrument details are provided in companion papers in this same issue. In this paper, we describe the science objectives of the RBSP-ECT instrument suite on the Van Allen Probe spacecraft within the context of the overall mission objectives, indicate how the characteristics of the instruments satisfy the requirements to achieve these objectives, provide information about science data collection and dissemination, and conclude with a description of some early mission results.