The IMpulsive Phase Rapid Energetic Solar Spectrometer CubeSat

The IMpulsive Phase Rapid Energetic Solar Spectrometer (IMPRESS) is a 3U NSF-Funded cube-satellite that contains a scintillation detector optimized to observe X-ray spectra from a wide range of solar flares (targeting C1 to X1 class flares) without saturating the detector and without moving attenuators.The mission’s main objective is to investigate solar flares by resolving sub-second fluctuations in the hard X-ray flux that are closely related with the electron acceleration processes by measuring X-rays from 5-100keV at a 32Hz cadence. Hard X-ray emission (HXR) from solar flares can be analyzed to explore flare particle acceleration dynamics. Prior studies using Fermi/GBM and RHESSI data have found fast hard HXR variations on timescales of < 10s, but no lower limit to the durations of these limitations has yet been uncovered. IMPRESS is designed to observe both soft X-ray (4 to 12 keV) and hard X-ray (10 to 300 keV) emission from solar flares with tens-of-millisecond time resolution to better constrain the timescales of HXR spikes and associated acceleration mechanisms. The project is a collaboration between UMN, MSU, UCSC, and SwRI.