The Compact Radiation BElt Explorer (CeREs) is a 3U CubeSat that is part of NASA’s Low-Cost Access to Space program. CeREs will primarily be focusing on radiation belt electrons, studying the energization and loss processes of these electrons, low-energy seed populations for the radiation belts, and microbursts. A secondary science goal for CeREs is the characterization of solar wind electrons and solar energetic protons (SEPs) that reach the near-Earth environment. CeREs will fly the Miniaturized Electron and PRoton Telescope (MERiT), that consists of a low energy-range silicon avalanche photodiode (APD) sitting on top of a stack of silicon solid state detectors (SSDs). The CeREs CubeSat is a collaboration between SwRI, NASA, and University of Maryland, where SwRI has contributed the APD detector and serves as the mission science operations center.