For refining cosmochemical studies, we are investigating the statistical equilibrium (non-LTE) of neutral and singly-ionized calcium (CaI/II) in the atmospheres of solar-type stars. The envisioned applications are a) detailed abundance studies beyond classical models, b) using CaI/II as a gravity indicator for ultra-metal-poor (UMP) stars and c) detailed modelling of the CaII IR triplet lines for the astrophysical parametrization of the Gaia mission. We present first results for some well-studied reference cases, both at solar and low metallicity.