Analysis and Modeling of the Data from CubeSat: Colorado Student Space Weather Experiment (CSSWE)

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The electron radiation environment around Earth is a major hazard to spaceflight assets. Understanding it, ideally to the point of predictive modeling of its response to changing solar wind driving conditions, is a central goal of magnetospheric physics. The condition in the radiation belts at any given time is the result of a delicate balance between energization and loss processes operating on the particles in the near-Earth environment. Neither of these is well understood at present. This project will use new measurements from a NSF-funded CubeSat mission that was recently carried out together with numerical modeling to determine the energetic electron loss rate. Only when the loss rate is accurately determined will it be possible to fully model the radiation belt dynamics. The Colorado Student Space Weather Experiment (CSSWE) is a tiny, so-called CubeSat, satellite mission funded by NSF and launched into a high inclination, low-altitude orbit as a secondary payload under NASA?s Educational Launch of Nanosatellites (ELaNa) program in September 2012. The entire CSSWE system, including its ground station, was designed, built, calibrated, tested, delivered, and operated by students, with mentoring and help provided by faculty and professional engineers at the Laboratory for Atmospheric and Space Physics at University of Colorado. The satellite project far exceeded it?s expected life-time and has collected more than 12 months worth of high quality data on energetic electrons and protons in Low-Earth-Orbit. The advanced data analysis to be done under this award will continue the exploitation of this unique dataset and, in turn, will help to maximize the scientific return on investment of this already highly successful CubeSat project. For the most part, the scientific investigation is designed for and will be carried out by graduate students under the supervision of the PI and collaborators. To date, the precipitation loss rate of the outer radiation belt electrons has not been quantified and resolved. The electron loss rates in current published papers are erratic and diverge by an order of magnitude. The goal of this study is to quantify the precipitation losses and their dependence on longitude, L, and MLT directly from the data with advanced modeling, thus providing a quantitative answer to the research community on this important issue. Specifically, this effort will analyze over a year's worth of CSSWE data in conjunction with the NASA Van Allen Probes to determine the loss rates into the ionosphere during periods of gradual decay, during episodes of fast loss and during episodes of large gain. Analyzing CSSWE data during periods of gradual loss will determine how much additional energization occurs during such periods to maintain the radiation belts; analyzing the data during periods of fast loss will determine how much of the loss occurs by scattering into the ionosphere versus loss due to outward radial diffusion; analyzing the loss during periods of large gains will determine how much additional energization is needed to produce the observed gains in electron flux. The impact of such precipitation loss to the overall dynamics of radiation belt electrons will then be assessed by comparing the measurements of CSSWE and the corresponding modeling results with measurements from the Van Allen Probes at the same times and locations.