Technologies

Mirrors for space applications, besides featuring suitable optical properties, should be light, resistant to mechanical stresses, and unsensitive to light-shadow thermal cycling. The standard optical materials easily fulfill optical and thermal requirements, but are fragile, and the mirrors must be thick (typically 1/6 of the diameter). For this reason they are heavy, and the only available solution is to lighten them, by removing material from the back side, still preserving the necessary mechanical robustness and optical quality.

The working principle of VTTJ is extremely simple. Two parts (at least one with tube shape) are screwed one into the other with a mechanical interference that creates a metallic seal. One part presents a cylindrical slot, the other presents a conical ring, whose diameter is slightly larger than the one of the cylindrical slot. When the two parts are screwed together, a plastic deformation occurs in the mechanical interference region.