Presentation #207.04 in the session Coronal Spectroscopy: New Results and Future Instruments.
The CubeSat Imaging X-ray Solar Spectrometer (CubIXSS) is a 6U CubeSat funded under NASA H-FORT. CubIXSS is motivated by a compelling overarching science question: what are the origins of hot plasma in solar flares and active regions? CubIXSS addresses its science question through sensitive, precise measurements of abundances of key trace ion species, which are a unique diagnostic of how mass and energy flow into and within the corona, and whose spectral signatures thus reveal the chromospheric or coronal origins of heated plasma across the entire temperature range from ~1 to >30 MK. CubIXSS measurements of the coronal temperature distribution and elemental abundances directly address longstanding inconsistencies from prior studies using instruments with limited, differing temperature and composition sensitivities.CubIXSS comprises two co-optimized and cross-calibrated instruments that fill a critical observational gap:* MOXSI, a novel diffractive spectral imager using a pinhole camera and X-ray transmission diffraction grating for spectroscopy of flares and active regions over an unprecedented spectral range of 1 to >55 Å; and* SASS, a suite of four spatially-integrated off-the-shelf spectrometers for high-cadence, high-sensitivity X-ray spectra of lines and continuum from 0.5 to >30 keV.CubIXSS is currently at the end of Phase B and plans to launch in early to mid-2025 to observe intense solar flares and active regions during the peak of the solar cycle. Its 1-year prime mission is well timed with perihelia of Parker Solar Probe and Solar Orbiter, and with the launches of complementary missions such as SunCET and PUNCH. CubIXSS is a pathfinder for the next generation of Explorer-class missions with improved capabilities for SXR imaging spectroscopy.We present the CubIXSS motivating science background, its suite of instruments and expected performances, and its current status and projected outlook, as well as additional planned developments including novel analysis techniques to fully exploit the rich data set of CubIXSS spectral observations.