using the Miniature X-ray Solar Spectrometer (MinXSS) CubeSats to Probe HOT plasma in the atmosphere of a COOL star

The Sun is the closest star to Earth and hence provides a unique opportunity to study numerous stellar phenomena in detail unprecedented to other stars. One such phenomena, which is a longstanding mystery, is coronal heating of low mass stars. The solar corona contains plasma in excess of 1 MK at all times, strong concentrations of magnetic field called active region contain plasma at least up to 3 MK, and large flares heat plasma above 10 MK. Solar flares accelerate particles into the solar atmosphere and into interplanetary space and emit copious high energy electromagnetic radiation, such as soft X-rays (sxr). Hence sxr measurements provide an early warning for any pending geomagnetic affects as a result of solar flares. Additionally, the detection of sxr from the Sun provide direct information on coronal plasma of temperatures in excess of ~1 MK, but there have been relatively few solar spectrally resolved measurements from 0.5 – 10. keV. CubeSats can be a low-cost alternative to rapidly fill astrophysical observation gaps, that large missions are currently missing. The twin Miniature X-ray Solar Spectrometer (MinXSS) CubeSats are the first solar science oriented CubeSat missions flown for the NASA Science Mission Directorate. The twin MinXSS have provided measurements from 0.8 -12 keV, with resolving power ~40 at 5.9 keV, at a nominal ~10 second time cadence. have proven to be consistent with numerous solar observations, proving the scientific capability of CubeSats.