The manufacturing method is described and the results of the study of the X-ray optical properties of a concave spherical mirror made of crystalline quartz are presented. The radius of curvature was 1630 mm. The shape of the mirror surface was studied on an interferometer with a diffraction wave of comparison. It was shown that in the whole processing area the maximum deviation from the nearest sphere was about 0.2 μm, and the square root of rms is 34 nm, which ensures high quality of images with an angular error of 2” (angular seconds). The reflection coefficients (about 7%) and the lower estimate of the spectral selectivity (λ / delta λ = 1775) are determined in the vicinity of the wavelength λ = 0.834 nm, which is close to the working wavelengths of the MgXII doublet (λ = 0.8418 and 0.8423 nm). During the bending of the crystal mirror, no change in the position of the Bragg peak and spectral selectivity was found within the limits of the accuracy of measurements.

Within the Universat program, a set of solar vacuum ultraviolet (VUV) telescopes has been developed for deployment on 6U nanosatellites. Telescopes are designed to get images of the solar corona. The spectral ranges of observations is considered, the characteristics of the nanosatellite from the point of view of the observations feasibility are opmized, the optical scheme of the telescope and VUV multilayer mirrors coatings and thin-film filters are modelled.