A group for allowing free orientation of a sphere with respect to outside force fields includes a support structure, a sphere, two locking elements acting from opposite sides on the sphere and useful to keep the sphere in a right position during a nonoperational phase of the group, at least four drop supports located around the sphere and able to form drops and to keep them at a desired temperature, and an isolation structure useful to isolate the above devices from the surroundings and to prevent dust deposition on the sphere surface and the four realized drops, and cooling device able to keep the sphere at a temperature lower than that of the drops.