CALOS: an experiment to study the solar corona with an array of NTD Ge microcalorimeters

In response to the Italian Space Agency announcement "New Ideas for Space Missions", we have proposed an observatory "CALorimetri per Osservazioni Solari" (CALOS) that will perform spatially resolved (Deltatheta similar to 2) X-ray spectroscopy of the solar corona over the 0.1 - 10 keV band using an array of NTD germanium microcalorimeters. The observatory will also include an X-ray polarimeter of radically new design that will study the hard X-ray solar emission and its polarization and will serve as a flare alarm.