How the corona is heated to tens of megakelvin (MK) in solar flares and quiescent (non-flaring) active regions is still poorly understood. Elemental abundances are a unique diagnostic of how mass…

Southwest Research Institute (SwRI) was awarded a $6.4M cooperative agreement by a civilian federal agency on April 1, 2022, for the CubeSat Imaging X-Ray Solar Spectrometer (CubIXSS) mission, with completion targeted for May 31, 2026. CubIXSS is a scientific research initiative designed to address fundamental questions about solar corona heating mechanisms during solar flares and quiescent active regions by measuring elemental abundances and spectral signatures across soft X-ray wavelengths (0.25–3 kiloelectron volts). The mission builds on heritage from prior pathfinder programs including MinXSS-1 and SDO/EVE sounding rockets, providing unprecedented soft X-ray spectroscopy with improved spectral coverage and dynamic range to simultaneously measure key low and high first ionization potential (FIP) ion species across the entire coronal temperature range from approximately 1 to greater than 30 megakelvin.

The contract supports two primary objectives: measuring how elemental abundances vary within and across solar flares to test chromospheric evaporation and direct coronal heating models, and demonstrating spatial resolution capabilities to quantify individual active region contributions to total soft X-ray spectra. This cooperative agreement represents no set-aside contract and leverages SwRI's established expertise in space science research and advanced instrumentation development. The work will be performed at SwRI's San Antonio, Texas facility, where the institute's multidisciplinary team will conduct the necessary research, development, and instrument operations to advance understanding of hot plasma formation mechanisms in the solar corona.

How the corona is heated to tens of megakelvin (MK) in solar flares and quiescent (non-flaring) active regions is still poorly understood. Elemental abundances are a unique diagnostic of how mass and energy flow into and within the corona.