Abstract: The real surface of the mirror is represented by a set of values corresponding to radial or approximately radial distances between points distributed over the surface of the mirror and a spherical reference surface. The method is implemented by using apparatus comprising a support provided with at least three abutments suitable for supporting the support and distributed or suitable for being distributed as points on the surface of a sphere, the support also carrying at least one distance sensor. The invention is particularly suitable for inspecting the optical parameters of a plane, spherical, or aspherical mirror, and in particular mirrors for telescopes.

Abstract: The invention pertains to a method to test the polishing of a mirror by means of a testing device, in a fluid through which rays of light are propagated homogeneously, and a system that puts this method into use. The method consists in placing the mirror on a support, in fixing this support imperviously to one end of a flexibly shaped and/or folding chamber in such a way that its internal volume can be elminated, the testing device being at an opposite end of the chamber, and it further consists in driving out the residual air contained in the chamber is driven out by eliminating its internal volume, then in injecting a volume of fluid into the chamber so that the polishing can be tested, the said testing being done before the support and the mirror are removed in order to correct faults or to finally package the mirror.

Abstract: The invention relates to a mirror having a non-plane reflecting face (M.sub.2), said mirror being constituted by a mass of optical material (M) having cells (A) formed therein in such a manner that the centers of gravity (g) of the portions of mirror material surrounding each cell lie in the same plane as the center of gravity (G) of the mirror as a whole. The invention is particularly applicable to large diameter mirrors used in telescopes and whose optical axes are generaly used in a horizontal position (or close thereto). The aim of the invention is to reduce the distortion phenomena which may occur due to the mirror bending under its own weight.

Abstract: The invention relates to a mounting device for supporting a component, especially a mirror or an antenna reflector in a spacecraft. The device comprises a combination of flexible blades disposed between the support, and between the intermediate piece and the component.