The effect of the doping by compounds with bivalent and trivalent cations (BN, Al2O3, MgO + SiO2) on the diffuse reflectance spectra (ρλ) and the integral solar absorptance (as) and their changes at irradiation (with 30 keV electrons, 3 keV protons, and electromagnetic radiation that imitates solar spectra) of the reflecting thermal control coatings based on ZrO2 powders is examined. The coating based on untreated ZrO2 pigment and the coatings based on the pigments treated with 1 and 3 mass% of Al2O3 nanopowder were subjected to simultaneous action of electrons, protons, and electromagnetic radiation that imitates action of these irradiations on geostationary satellite orbit. After that, the comparative investigations of the changes in spectral reflectance and solar absorptance of these coatings were carried out.