Colorado Student Space Weather Experiment: Differential Flux Measurements of Energetic Particles in a Highly Inclined Low Earth Orbit

The Colorado Student Space Weather Experiment (CSSWE) is a three-unit (10 cm x 10 cm x 30 cm) CubeSat mission.funded by the National Science Foundation; it was launched into a low Earth, polar orbit on 13 September 2012 as a secondary payload under NASA's Educational Launch of Nanosatellites program. The science objectives of CSSWE are to investigate the relationship of the location, magnitude, and frequency of solar flares to the timing, duration, and energy spectrum of solar energetic particles reaching Earth and to determine the precipitation loss and the evolution of the energy spectrum of radiation belt electrons. CSSWE contains a single science payload, the Relativistic Electron and Proton Telescope integrated little experiment (REPTile), which is a miniaturization of the Relativistic Electron and Proton Telescope (REPT) built at the Laboratory for Atmospheric and Space Physics. The REPT instrument will fly onboard the NASA Radiation Belt Storm Probes mission, which consists of two identical spacecraft launched on 30 August 2012 that will go through the heart of the radiation belts in a low-inclination orbit. CSSWE's REPTile is designed to measure the directional differential flux of protons ranging from 10 to 40 MeV and electrons from 0.5 to >3 MeV. Such differential flux measurements have significant science value, and a number of engineering challenges were overcome to enable these clean measurements to be made under the mass and power limits of a CubeSat. The CSSWE is an ideal class project, providing training for the next generation of engineers and scientists over the full life cycle of a satellite project.